feat: 新增LoRA微调模块

- LoRALinear基于register_parameter托管base weight，state_dict路径不变 - inject_lora/merge_lora/save_lora/load_lora完备封装 - 24个单元测试覆盖注入、合并、存取、边界场景
2026-05-25 20:11:25 +08:00
145 changed files with 3522 additions and 19981 deletions
@@ -1,92 +0,0 @@
-name: Release
-
-on:
-  push:
-    tags:
-      - "v*"
-
-jobs:
-  build-pure:
-    name: Build pure-Python wheel
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
-        with:
-          python-version: "3.12"
-
-      - name: Build wheel (no CUDA)
-        run: |
-          pip wheel . --no-deps -w dist/
-
-      - uses: actions/upload-artifact@v4
-        with:
-          name: pure-wheel
-          path: dist/*.whl
-          if-no-files-found: error
-
-  build-cuda-linux:
-    name: Build CUDA wheel (Linux)
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
-        with:
-          python-version: "3.12"
-
-      - name: Install torch (CUDA 12.8)
-        run: |
-          pip install torch --index-url https://download.pytorch.org/whl/cu128
-
-      - name: Setup CUDA
-        uses: Jimver/cuda-toolkit@v0.2.35
-        with:
-          cuda: "12.8.0"
-
-      - name: Build wheel (with CUDA kernels)
-        run: |
-          CSRC_KERNELS=true pip wheel . --no-deps --no-build-isolation -w dist/
-
-      - uses: actions/upload-artifact@v4
-        with:
-          name: cuda-wheel-linux
-          path: dist/*.whl
-          if-no-files-found: error
-
-  release:
-    name: Attach wheels to release
-    needs: [build-pure, build-cuda-linux]
-    runs-on: ubuntu-latest
-    permissions:
-      contents: write
-    steps:
-      - name: Download pure-Python wheel
-        uses: actions/download-artifact@v4
-        with:
-          name: pure-wheel
-          path: release-assets/pure
-
-      - name: Download CUDA wheel
-        uses: actions/download-artifact@v4
-        with:
-          name: cuda-wheel-linux
-          path: release-assets/cuda
-
-      - name: Verify release assets
-        shell: bash
-        run: |
-          set -euo pipefail
-          pure_wheels=(release-assets/pure/*.whl)
-          cuda_wheels=(release-assets/cuda/*.whl)
-          test "${#pure_wheels[@]}" -eq 1
-          test "${#cuda_wheels[@]}" -eq 1
-          test "$(basename "${pure_wheels[0]}")" != "$(basename "${cuda_wheels[0]}")"
-
-      - name: Create release & upload assets
-        uses: softprops/action-gh-release@v2
-        with:
-          files: |
-            release-assets/pure/*.whl
-            release-assets/cuda/*.whl
-          tag_name: ${{ github.ref_name }}
-          generate_release_notes: true
@@ -5,16 +5,8 @@
 !*/

 # Allow specific file types and root files
-!astrai/**/*.py
-!scripts/**/*.py
-!tests/**/*.py
-!csrc/**/*.py
-
-!csrc/**/*.cu
-!csrc/**/*.h
-!csrc/**/*.cuh
-
-!scripts/**/*.sh
+!*.py
+!*.sh

 # Allow GitHub files
 !/.github/**
@@ -28,9 +20,4 @@
 !/CONTRIBUTING.md
 !/LICENSE
 !/pyproject.toml
-!/README.md
-# Allow extension modules (only source .py)
-!/astrai/extension/**/*.py
-
-# Allow build files
-!/setup.py
+!/README.md
@@ -5,7 +5,7 @@ Thank you for your interest in contributing! This document provides step-by-step
 ## Quick Start

 ```bash
-git clone https://github.com/ViperEkura/AstrAI.git
+git clone https://github.com/your-username/AstrAI.git
 cd AstrAI
 pip install -e ".[dev]"     # install with dev dependencies (pytest, ruff)
 ```
@@ -23,7 +23,7 @@ COPY astrai/ ./astrai/
 COPY pyproject.toml .
 RUN pip install --no-cache-dir --upgrade pip \
    && pip install --no-cache-dir . \
-    --extra-index-url https://download.pytorch.org/whl/cu128
+    --extra-index-url https://download.pytorch.org/whl/cu126

 # Production stage
 FROM ubuntu:24.04 AS production
@@ -9,9 +9,9 @@
 <div align="center">
  <img src="https://img.shields.io/badge/python-3.12+-blue.svg" alt="python">
  <img src="https://img.shields.io/badge/license-GPL--3.0-blue.svg" alt="license">
-  <img src="https://img.shields.io/github/v/tag/ViperEkura/AstrAI?label=Release&color=76bad9" alt="release">
-  <img src="https://img.shields.io/github/stars/ViperEkura/AstrAI?style=flat&label=Stars&color=76bad9" alt="stars">
-  <img src="https://img.shields.io/github/forks/ViperEkura/AstrAI?style=flat&label=Forks&color=76bad9" alt="forks">
+  <img src="https://img.shields.io/github/v/release/ViperEkura/AstrAI?color=76bad9" alt="release">
+  <img src="https://img.shields.io/badge/dynamic/json?url=https%3A%2F%2Fapi.github.com%2Frepos%2FViperEkura%2FAstrAI&query=%24.stargazers_count&label=stars&suffix=%20stars&color=76bad9" alt="stars">
+  <img src="https://img.shields.io/badge/dynamic/json?url=https%3A%2F%2Fapi.github.com%2Frepos%2FViperEkura%2FAstrAI&query=%24.forks_count&label=forks&suffix=%20forks&color=76bad9" alt="forks">
 </div>
 <br>

@@ -20,7 +20,7 @@
  <a href="assets/docs/README-zh-CN.md">中文</a> •
  <a href="https://github.com/ViperEkura/AstrAI/issues">Issue Tracker</a> •
  <a href="https://github.com/ViperEkura/AstrAI/discussions">Discussions</a> •
-  <a href="https://huggingface.co/ViperEkura">HuggingFace</a>
+  <a href="https://huggingface.co/ViperEk/">HuggingFace</a>
 </div>

 <br>
@@ -28,8 +28,7 @@
 ## 📖 Table of Contents

 - [Features](#features)
- [Getting Started](#getting-started)
- [Demo](#demo)
+- [Quick Start](#quick-start)
 - [Documentation](#documentation)
 - [Contributing](#contributing)
 - [Community](#community)
@@ -50,51 +49,39 @@
 - 🤗 **HuggingFace-Style API**: AutoModel/AutoTokenizer APIs inspired by HuggingFace for easy model and tokenizer loading.
 - 🔌 **Dual API Compatibility**: Supports both OpenAI and Anthropic chat completion APIs out of the box.

-### Getting Started
+### Quick Start

-End-to-end walkthrough in 5 steps:
-
-**1. Install**
+#### Installation

 ```bash
 git clone https://github.com/ViperEkura/AstrAI.git
 cd AstrAI
-pip install -e .                                          # pure PyTorch (no CUDA kernels)
-# CSRC_KERNELS=true pip install -e . --no-build-isolation  # optional: fused CUDA kernels
-# pip install -e ".[dev]"                                  # dev dependencies (pytest, ruff)
+pip install -e .
 ```

-**2. Download model**
+For development dependencies:

 ```bash
-python scripts/demo/download.py    # downloads 1B checkpoint to params/
+pip install -e ".[dev]"
 ```

-**3. Preprocess data**
+#### Download Pre-trained Model

-Create `pretrain.json` (preprocessing config for `seq` strategy):
-
-```json
-{
-    "version": 1,
-    "input": {"sections": [{"field": "text", "action": "train"}]},
-    "preprocessing": {"max_seq_len": 2048},
-    "output": {"storage_format": "bin"}
-}
-```
+Download pre-trained model weights (1B bilingual checkpoint) to `params/`:

 ```bash
-python scripts/tools/preprocess.py data/*.jsonl -o output/ -c pretrain.json
+python scripts/demo/download.py
 ```

-**4. Train**
+Or download manually from [HuggingFace](https://huggingface.co/ViperEk/KHAOSZ) into `params/`.
+
+#### Train a Model

 ```bash
 export CUDA_VISIBLE_DEVICES=0,1,2,3

 nohup python scripts/tools/train.py \
    --nprocs=4 \
-    --parallel_mode=ddp \
    --train_type=seq \
    --data_root_path=/path/to/dataset \
    --param_path=/path/to/model \
@@ -103,7 +90,9 @@ nohup python scripts/tools/train.py \
    --warmup_ratio=0.05 \
    --max_lr=1e-4 \
    --max_grad_norm=1.0 \
-    --weight_decay=0.1 \
+    --adamw_beta1=0.9 \
+    --adamw_beta2=0.95 \
+    --adamw_weight_decay=0.01 \
    --window_size=2048 \
    --ckpt_interval=10000 \
    --ckpt_dir=./checkpoint \
@@ -112,54 +101,15 @@ nohup python scripts/tools/train.py \
    > out.log 2> err.log &
 ```

-**5. Serve & query**
+Full reference at [Parameter Guide](assets/docs/params.md).

-```bash
-# Terminal 1: start server
-python scripts/tools/server.py --param_path ./params --device cuda
-
-# Terminal 2: query
-curl http://localhost:8000/v1/chat/completions \
-  -H "Content-Type: application/json" \
-  -d '{"messages":[{"role":"user","content":"Hello"}],"max_tokens":512}'
-```
-
-### Demo
-
-Check out the demos in the `scripts/demo/` folder:
-
-```bash
-# Download model weights (required before running demos)
-python scripts/demo/download.py                      # model → params/
-
-# Interactive streaming chat (multi-turn, maintains history)
-python scripts/demo/stream_chat.py
-# Type your message after >>, type !exit to quit
-
-# Batch generation (5 hardcoded prompts, non-streaming)
-python scripts/demo/generate_batch.py
-
-# Single-prompt autoregressive streaming
-python scripts/demo/generate_ar.py
-```
-
-All generation demos use `temperature=0.8`, `top_p=0.95`, `top_k=50`, `max_tokens=2048` by default and require `params/` to contain model weights (run `download.py` first).
-
-Watch a video walkthrough on [bilibili](https://www.bilibili.com/video/BV1fuLB6yEj6).
-
---
-
-See [Documentation](#documentation) for full references beyond the examples above.
-
-#### Text Generation
-
-Batch generation from a JSONL file:
+#### Generate Text

 ```bash
 python scripts/tools/generate.py \
-    --param_path ./params \
-    --input_json_file input.jsonl \
-    --output_json_file output.jsonl
+    --param_path /path/to/model \
+    --input_json_file /path/to/input.json \
+    --output_json_file /path/to/output.json
 ```

 #### Docker
@@ -173,6 +123,9 @@ docker build -t astrai:latest .
 # Run with GPU support
 docker run --gpus all -it astrai:latest

+# Run with specific GPUs
+docker run --gpus '"device=0,1"' -it astrai:latest
+
 # Run inference server
 docker run --gpus all -p 8000:8000 astrai:latest \
  python -m scripts.tools.server --port 8000 --device cuda
@@ -189,42 +142,88 @@ docker compose --profile cpu up -d

 > **Note**: `--gpus all` is required for CUDA support. Without it, `torch.cuda.is_available()` will return `False`.

-#### HTTP API Examples
+#### Start HTTP Server

-Additional request examples beyond the [Getting Started](#getting-started) flow:
+Start the inference server with OpenAI and Anthropic-compatible HTTP API:

 ```bash
+python -m scripts.tools.server --port 8000 --device cuda
+```
+
+Make requests:
+
+```bash
+# OpenAI-compatible
+curl -X POST http://localhost:8000/v1/chat/completions \
+  -H "Content-Type: application/json" \
+  -d '{
+    "messages": [{"role": "user", "content": "Hello"}],
+    "max_tokens": 512
+  }'
+
 # OpenAI-compatible streaming
 curl -X POST http://localhost:8000/v1/chat/completions \
  -H "Content-Type: application/json" \
-  -d '{"messages":[{"role":"user","content":"Tell a story"}],"stream":true,"max_tokens":500}'
+  -d '{
+    "messages": [{"role": "user", "content": "Tell a story"}],
+    "stream": true,
+    "max_tokens": 500
+  }'

 # Anthropic-compatible
 curl -X POST http://localhost:8000/v1/messages \
  -H "Content-Type: application/json" \
-  -d '{"model":"astrai","system":"You are a helpful assistant.","messages":[{"role":"user","content":"Hello"}],"max_tokens":512}'
+  -d '{
+    "model": "astrai",
+    "system": "You are a helpful assistant.",
+    "messages": [{"role": "user", "content": "Hello"}],
+    "max_tokens": 512
+  }'

 # Anthropic-compatible streaming with stop sequences
 curl -X POST http://localhost:8000/v1/messages \
  -H "Content-Type: application/json" \
-  -d '{"model":"astrai","messages":[{"role":"user","content":"Write a story"}],"max_tokens":500,"stream":true,"stop_sequences":["The end"]}'
+  -d '{
+    "model": "astrai",
+    "messages": [{"role": "user", "content": "Write a story"}],
+    "max_tokens": 500,
+    "stream": true,
+    "stop_sequences": ["The end"]
+  }'

 # Health check
 curl http://localhost:8000/health
 ```

-See [Inference Guide](assets/docs/inference.md) for SSE streaming format, error codes, and stats endpoint.
+#### Demo
+
+Check out the demos in the `scripts/demo/` folder:
+
+```bash
+# Download pre‑processed data (required before running demos)
+python scripts/demo/download.py
+
+# Interactive streaming chat
+python scripts/demo/stream_chat.py
+
+# Batch generation
+python scripts/demo/generate_batch.py
+
+# Auto‑regressive generation
+python scripts/demo/generate_ar.py
+```
+
+Watch a video walkthrough on [bilibili](https://www.bilibili.com/video/BV1fuLB6yEj6).

 ### Documentation

 | Document | Description |
 |----------|-------------|
-| [CLI Reference](./assets/docs/params.md) | Parameters for all CLI tools (train, server, generate, preprocess) |
+| [Parameter Guide](./assets/docs/params.md) | Training & inference parameters |
 | [Architecture](./assets/docs/architecture.md) | System architecture, class diagram & design patterns |
 | [Training](./assets/docs/training.md) | Training loop, strategies & formulas |
 | [Inference](./assets/docs/inference.md) | KVCache, continuous batching, sampling & HTTP API |
 | [Data Flow](./assets/docs/dataflow.md) | Data pipeline, storage backends & dataset architecture |
-| [Preprocessing](./assets/docs/preprocessing.md) | Declarative JSON-driven data preprocessing |

 ### Contributing

@@ -241,7 +240,7 @@ For major changes, please open an issue first to discuss what you would like to

 - **GitHub Issues**: [Issue Tracker](https://github.com/ViperEkura/AstrAI/issues)
 - **Discussions**: [GitHub Discussions](https://github.com/ViperEkura/AstrAI/discussions)
- **HuggingFace**: [Model Hub](https://huggingface.co/ViperEkura)
+- **HuggingFace**: [Model Hub](https://huggingface.co/ViperEk)

 ### License

@@ -15,9 +15,9 @@
 <div align="center">
  <img src="https://img.shields.io/badge/python-3.12+-blue.svg" alt="python">
  <img src="https://img.shields.io/badge/license-GPL--3.0-blue.svg" alt="license">
-  <img src="https://img.shields.io/github/v/tag/ViperEkura/AstrAI?label=Release&color=76bad9" alt="release">
-  <img src="https://img.shields.io/github/stars/ViperEkura/AstrAI?style=flat&label=Stars&color=76bad9" alt="stars">
-  <img src="https://img.shields.io/github/forks/ViperEkura/AstrAI?style=flat&label=Forks&color=76bad9" alt="forks">
+  <img src="https://img.shields.io/github/v/release/ViperEkura/AstrAI?color=76bad9" alt="release">
+  <img src="https://img.shields.io/badge/dynamic/json?url=https%3A%2F%2Fapi.github.com%2Frepos%2FViperEkura%2FAstrAI&query=%24.stargazers_count&label=stars&suffix=%20stars&color=76bad9" alt="stars">
+  <img src="https://img.shields.io/badge/dynamic/json?url=https%3A%2F%2Fapi.github.com%2Frepos%2FViperEkura%2FAstrAI&query=%24.forks_count&label=forks&suffix=%20forks&color=76bad9" alt="forks">
 </div>

 <br>
@@ -27,15 +27,14 @@
  <a href="#chinese">中文</a> •
  <a href="https://github.com/ViperEkura/AstrAI/issues">问题追踪</a> •
  <a href="https://github.com/ViperEkura/AstrAI/discussions">讨论区</a> •
-  <a href="https://huggingface.co/ViperEkura">HuggingFace</a>
+  <a href="https://huggingface.co/ViperEk">HuggingFace</a>
 </div>
 <br>

 ## 📖 目录

 - [特性](#特性)
- [快速上手](#快速上手)
- [演示](#演示)
+- [快速开始](#快速开始)
 - [文档](#文档)
 - [贡献](#贡献)
 - [社区](#社区)
@@ -56,51 +55,39 @@
 - 🤗 **HuggingFace 风格 API**: 类 HuggingFace 的 AutoModel/AutoTokenizer 接口，方便加载模型和分词器。
 - 🔌 **双 API 兼容**: 同时支持 OpenAI 和 Anthropic 聊天补全 API，开箱即用。

-### 快速上手
+### 快速开始

-端到端演示，只需 5 步：
-
-**1. 安装**
+#### 安装

 ```bash
 git clone https://github.com/ViperEkura/AstrAI.git
 cd AstrAI
-pip install -e .                                          # 纯 PyTorch（不含 CUDA 内核）
-# CSRC_KERNELS=true pip install -e . --no-build-isolation  # 可选：融合 CUDA 内核加速
-# pip install -e ".[dev]"                                  # 可选：开发依赖（pytest, ruff）
+pip install -e .
 ```

-**2. 下载模型**
+安装开发依赖：

 ```bash
-python scripts/demo/download.py    # 下载 1B 检查点到 params/
+pip install -e ".[dev]"
 ```

-**3. 预处理数据**
+#### 下载预训练模型

-创建 `pretrain.json`（`seq` 策略的预处理配置）：
-
-```json
-{
-    "version": 1,
-    "input": {"sections": [{"field": "text", "action": "train"}]},
-    "preprocessing": {"max_seq_len": 2048},
-    "output": {"storage_format": "bin"}
-}
-```
+下载预训练模型权重（1B 双语检查点）到 `params/` 目录：

 ```bash
-python scripts/tools/preprocess.py data/*.jsonl -o output/ -c pretrain.json
+python scripts/demo/download.py
 ```

-**4. 训练**
+或从 [HuggingFace](https://huggingface.co/ViperEk/KHAOSZ) 手动下载放入 `params/`。
+
+#### 训练模型

 ```bash
 export CUDA_VISIBLE_DEVICES=0,1,2,3

 nohup python scripts/tools/train.py \
    --nprocs=4 \
-    --parallel_mode=ddp \
    --train_type=seq \
    --data_root_path=/path/to/dataset \
    --param_path=/path/to/model \
@@ -109,7 +96,9 @@ nohup python scripts/tools/train.py \
    --warmup_ratio=0.05 \
    --max_lr=1e-4 \
    --max_grad_norm=1.0 \
-    --weight_decay=0.1 \
+    --adamw_beta1=0.9 \
+    --adamw_beta2=0.95 \
+    --adamw_weight_decay=0.01 \
    --window_size=2048 \
    --ckpt_interval=10000 \
    --ckpt_dir=./checkpoint \
@@ -118,54 +107,15 @@ nohup python scripts/tools/train.py \
    > out.log 2> err.log &
 ```

-**5. 启动服务并调用**
-
-```bash
-# 终端 1：启动服务
-python scripts/tools/server.py --param_path ./params --device cuda
-
-# 终端 2：发起请求
-curl http://localhost:8000/v1/chat/completions \
-  -H "Content-Type: application/json" \
-  -d '{"messages":[{"role":"user","content":"你好"}],"max_tokens":512}'
-```
-
-### 演示
-
-查看 `scripts/demo/` 文件夹中的演示：
-
-```bash
-# 下载模型权重（运行演示前必需）
-python scripts/demo/download.py                      # model → params/
-
-# 交互式流式聊天（多轮对话，保持历史记录）
-python scripts/demo/stream_chat.py
-# 在 >> 后输入消息，输入 !exit 退出
-
-# 批量生成（5 条硬编码提示词，非流式）
-python scripts/demo/generate_batch.py
-
-# 单条提示词自回归流式生成
-python scripts/demo/generate_ar.py
-```
-
-所有生成演示默认使用 `temperature=0.8`、`top_p=0.95`、`top_k=50`、`max_tokens=2048`，需要 `params/` 目录包含模型权重（请先运行 `download.py`）。
-
-观看 [bilibili](https://www.bilibili.com/video/BV1fuLB6yEj6) 上的视频演示。
-
---
-
-更多选项请参考[文档](#文档)。
+完整参数列表见[参数说明](./params.md)。

 #### 文本生成

-从 JSONL 文件批量生成：
-
 ```bash
 python scripts/tools/generate.py \
-    --param_path ./params \
-    --input_json_file input.jsonl \
-    --output_json_file output.jsonl
+    --param_path /path/to/model \
+    --input_json_file /path/to/input.json \
+    --output_json_file /path/to/output.json
 ```

 #### Docker
@@ -179,6 +129,9 @@ docker build -t astrai:latest .
 # 启用 GPU 运行
 docker run --gpus all -it astrai:latest

+# 指定特定 GPU
+docker run --gpus '"device=0,1"' -it astrai:latest
+
 # 运行推理服务
 docker run --gpus all -p 8000:8000 astrai:latest \
  python -m scripts.tools.server --port 8000 --device cuda
@@ -195,42 +148,88 @@ docker compose --profile cpu up -d

 > **注意**: 必须使用 `--gpus all` 才能启用 CUDA 支持，否则 `torch.cuda.is_available()` 将返回 `False`。

-#### HTTP API 示例
+#### 启动 HTTP 服务

-除[快速上手](#快速上手)流程外，更多请求示例：
+启动推理服务器，支持 OpenAI 和 Anthropic 兼容的 HTTP API：

 ```bash
+python -m scripts.tools.server --port 8000 --device cuda
+```
+
+发起请求：
+
+```bash
+# OpenAI 兼容
+curl -X POST http://localhost:8000/v1/chat/completions \
+  -H "Content-Type: application/json" \
+  -d '{
+    "messages": [{"role": "user", "content": "你好"}],
+    "max_tokens": 512
+  }'
+
 # OpenAI 兼容流式
 curl -X POST http://localhost:8000/v1/chat/completions \
  -H "Content-Type: application/json" \
-  -d '{"messages":[{"role":"user","content":"讲个故事"}],"stream":true,"max_tokens":500}'
+  -d '{
+    "messages": [{"role": "user", "content": "讲个故事"}],
+    "stream": true,
+    "max_tokens": 500
+  }'

 # Anthropic 兼容
 curl -X POST http://localhost:8000/v1/messages \
  -H "Content-Type: application/json" \
-  -d '{"model":"astrai","system":"你是一个乐于助人的助手。","messages":[{"role":"user","content":"你好"}],"max_tokens":512}'
+  -d '{
+    "model": "astrai",
+    "system": "你是一个乐于助人的助手。",
+    "messages": [{"role": "user", "content": "你好"}],
+    "max_tokens": 512
+  }'

 # Anthropic 兼容流式并设置停止序列
 curl -X POST http://localhost:8000/v1/messages \
  -H "Content-Type: application/json" \
-  -d '{"model":"astrai","messages":[{"role":"user","content":"写个故事"}],"max_tokens":500,"stream":true,"stop_sequences":["结束"]}'
+  -d '{
+    "model": "astrai",
+    "messages": [{"role": "user", "content": "写个故事"}],
+    "max_tokens": 500,
+    "stream": true,
+    "stop_sequences": ["结束"]
+  }'

 # 健康检查
 curl http://localhost:8000/health
 ```

-SSE 流式格式、错误码和统计端点详见[推理文档](./inference.md)。
+#### 演示
+
+查看 `scripts/demo/` 文件夹中的演示：
+
+```bash
+# 下载预处理数据（运行演示前必需）
+python scripts/demo/download.py
+
+# 交互式流式聊天
+python scripts/demo/stream_chat.py
+
+# 批量生成
+python scripts/demo/generate_batch.py
+
+# 自回归生成
+python scripts/demo/generate_ar.py
+```
+
+观看 [bilibili](https://www.bilibili.com/video/BV1fuLB6yEj6) 上的视频演示。

 ### 文档

 | 文档 | 说明 |
 |------|------|
-| [CLI 参考](./params.md) | 所有 CLI 工具参数（训练、服务、生成、预处理） |
+| [参数说明](./params.md) | 训练与推理参数配置 |
 | [架构文档](./architecture.md) | 系统架构、类图与设计模式 |
 | [训练文档](./training.md) | 训练循环、策略与公式 |
 | [推理文档](./inference.md) | KVCache、连续批处理、采样与 HTTP API |
 | [数据流程](./dataflow.md) | 数据管道、存储后端与数据集架构 |
-| [数据预处理](./preprocessing.md) | 声明式 JSON 驱动数据预处理 |

 ### 贡献

@@ -247,7 +246,7 @@ SSE 流式格式、错误码和统计端点详见[推理文档](./inference.md)

 - **GitHub Issues**: [问题追踪](https://github.com/ViperEkura/AstrAI/issues)
 - **Discussions**: [GitHub 讨论区](https://github.com/ViperEkura/AstrAI/discussions)
- **HuggingFace**: [模型中心](https://huggingface.co/ViperEkura)
+- **HuggingFace**: [模型中心](https://huggingface.co/ViperEk)

 ### 许可证

@@ -1,119 +1,46 @@
 # Data Flow

-This document describes the data pipeline: from raw text to model input tensors. For creating preprocessing configs, see [Preprocessing Guide](preprocessing.md).
-
-## Contents
-
- [Overview](#overview)
- [Data Preparation](#data-preparation) — tokenization, format detection, backends
- [Data Keys by Training Type](#data-keys-by-training-type)
- [Dataset Architecture](#dataset-architecture)
- [Sampler](#sampler)
- [DataLoader](#dataloader)
+This document describes the data pipeline: from raw text to model input tensors.

 ## Overview

 ```
-JSONL Lines → Pipeline (mask builder) → Tokenized Tensors
-                                              ↓
-                                      .h5 or .bin storage
-                                              ↓
-                                      Store.load()
-                                              ↓
-                                      Store.fetch(begin, end, keys)
-                                              ↓
-                                      BaseDataset.__getitem__(idx)
-                                              ↓
-                                      Sampler → DataLoader → Training / Inference
+Raw Text → AutoTokenizer → Token IDs → .h5/.json → Dataset → Sampler → DataLoader → Training/Inference
 ```

 ## Data Preparation

-Raw text is tokenized via `AutoTokenizer.encode()` and saved as HDF5 (`.h5`) or binary (`.bin` + `meta.json`) files with keyed tensor groups.
-
-### Tokenization
-
-The `Pipeline` reads JSONL lines, applies the mask builder (see [Preprocessing](preprocessing.md)), and produces flat token sequences:
-
-```python
-# Per JSONL line: messages → chat template → token IDs + loss mask
-tokens = tokenizer.encode(rendered_text)        # List[int]
-loss_mask = [0, 0, 0, 1, 1, 1, 1, 1, 1]        # 0=masked, 1=train
-# Stored as flat tensors, packed with other lines by packing strategy
-```
-
-The output `meta.json` records the storage format, key names, dtype, total token count, and tensor shapes for each shard.
-
-### Format Detection
-
-`detect_format(load_path)` inspects the path:
-
- If `load_path` is a file: checks suffix — `.h5`/`.hdf5` → `"h5"`, `.jsonl` → `"jsonl"`, unknown suffix raises `ValueError`
- If `load_path` is a directory: recursively globs for `*.h5`/`*.hdf5` files → `"h5"`, `*.bin` + `**/meta.json` → `"bin"`, or `*.jsonl` + `dataset_config.json` → `"jsonl"`
-
-### Store Backends
+Raw text is tokenized via `AutoTokenizer.encode()` and saved as HDF5 (`.h5`) or JSON (`.json`/`.jsonl`) files with keyed tensor groups.

 Storage format is auto-detected by `detect_format()`; backends are dispatched via registry:

 ```
-StoreFactory.create("h5")    → H5Store
-StoreFactory.create("bin")   → MmapStore
-StoreFactory.create("jsonl") → JsonlStore
+StorageFactory.create("h5")   → H5Storage
+StorageFactory.create("json") → JSONStorage
 ```

-All three inherit `Store` (base, owns `_data`/`_cum`/`_offsets`/`_normalize`) plus the `Streamable` and `Recordable` mixins, so every backend supports both `fetch(begin, end, keys)` (stream) and `fetch_record(index, keys)` (record) APIs.
-
-**H5Store**: Reads HDF5 files. Tensors are loaded into host memory and normalized into segmented storage. `segments_are_records=True` — each `data_i` dataset is one record.
-
-**MmapStore**: Memory-maps `.bin` files. OS page cache sharing is native — no explicit `share_memory_()` needed. Uses `torch.from_numpy(np.memmap(...))`. `segments_are_records=False` — bin segments are contiguous streams; record access is driven by `_offsets` (written when `save_bin(..., record_keys=...)` was used at preprocessing time).
-
-**JsonlStore**: On-the-fly tokenization of raw JSONL files at load time. Requires a `dataset_config.json` alongside the `.jsonl` files following the same `PipelineConfig` schema with an additional `tokenizer_path` field. Two modes: eager (default, applies `TokenizeTransform` to all records at load) and lazy (`processor=fn` given, defers tokenisation to `fetch_record` — used by DPO/GRPO).
-
-All backends normalise tensors into `Store._data[Dict[str, List[Tensor]]]` + `Store._cum[Dict[str, List[int]]]` (cumulative lengths for bisect-based stream indexing) + `Store._offsets[Dict[str, List[int]]]` (per-record offsets for record-mode indexing). Nested keys (GRPO `responses`/`masks` as `List[List[Tensor]]`) are stored as-is and excluded from both bookkeepings — they are only accessed record-by-record.
+Both support shared memory via `.share_memory_()`.

 ## Data Keys by Training Type

-| Type | Storage Keys | Access Mode |
-|------|-------------|-------------|
-| `seq` | `sequence` (→ input_ids, target_ids via offset-by-1) | stream (`fetch`) |
-| `sft` | `sequence`, `loss_mask`, `position_ids` | stream (`fetch`) |
-| `dpo` | `chosen`, `rejected`, `chosen_mask`, `rejected_mask` | record (`fetch_record`) |
-| `grpo` | `prompts`, `responses`, `masks`, `rewards` | record (`fetch_record`) |
+| Type | Storage Keys |
+|------|-------------|
+| `seq` | `sequence` (→ input_ids, target_ids via offset-by-1) |
+| `sft` | `sequence`, `loss_mask` |
+| `dpo` | `chosen`, `rejected`, `chosen_mask`, `rejected_mask` |
+| `grpo` | `prompts`, `responses`, `masks`, `rewards` |

 ## Dataset Architecture

 ```
-DatasetFactory.load(train_type, load_path, window_size, stride=None,
-                    storage_type=None, tokenizer_path=None,
-                    max_position_embeddings=2048, store=None)
-  → BaseDataset.load(load_path, storage_type=None)
-    → detect_format(load_path)
-    → StoreFactory.create(storage_type)
-    → Store.load(load_path)
-      → _normalize(raw)  # base Store, shared by both backends
-        → Store._data[Dict[str, List[Tensor]]]
-          + _cum[Dict[str, List[int]]]   (stream mode)
-          + _offsets[Dict[str, List[int]]]  (record mode)
-
-Stream datasets (SEQ/SFT):
-  BaseDataset.__getitem__(idx)
-    → get_index(idx) → [begin, end)
-    → Store.fetch(begin, end, keys) → Tensor / Dict[str, Tensor]
-
-Record datasets (DPO/GRPO via RecordDataset):
-  RecordDataset.__getitem__(idx)
-    → Store.fetch_record(idx, keys) → Tensor / Dict[str, Tensor]
+DatasetFactory.load(train_type, path, window_size, stride)
+  → StorageFactory.create(detect_format(path))
+    → MultiSegmentFetcher(BaseSegmentFetcher per key)
+      → BaseDataset.__getitem__(idx)
+        → sliding window [begin, end) via get_index(idx)
 ```

-Class hierarchy: `BaseDataset` ← `SEQDataset` / `SFTDataset` (stream); `BaseDataset` ← `RecordDataset` ← `DPODataset` / `GRPODataset` (record).
-
-`window_size` = max input length, `stride` = step between consecutive samples (defaults to `window_size`, optional). Only meaningful for stream datasets — record datasets ignore both. `storage_type` defaults to `None` (auto-detect via `detect_format`).
-
-`tokenizer_path` triggers lazy on-the-fly tokenisation for record datasets on raw JSONL (DPO builds a `dpo_processor`; SEQ/SFT/pre-tokenised backends ignore it). `store` (pre-built `Store`) bypasses `load_path`/`storage_type`/`tokenizer_path` entirely — the caller controls Store construction.
-
-`Store.fetch(begin, end, keys)` (stream mode, on `Streamable`): accepts a single key (`str`) returning a `Tensor`, or a list of keys returning `Dict[str, Tensor]`. Internally uses `bisect` across multi-segment tensors. Raises `RuntimeError("Store not loaded")` if called before `load()`.
-
-`Store.fetch_record(index, keys)` (record mode, on `Recordable`): same key API. Uses `_offsets[key]` when present (bin layout with per-record offsets), otherwise indexes `_data[key]` directly (H5/JSONL where each segment is one record).
+`window_size` = max input length, `stride` = step between consecutive samples.

 ## Sampler

@@ -127,4 +54,4 @@ Class hierarchy: `BaseDataset` ← `SEQDataset` / `SFTDataset` (stream); `BaseDa

 Standard PyTorch `DataLoader` with configurable `batch_size`, `num_workers`, `pin_memory`, `prefetch_factor`. Sampler produces indices; dataloader fetches tensor batches via `__getitem__`.

-> Document Update Time: 2026-07-19
+> Document Update Time: 2026-05-17
@@ -1,16 +1,5 @@
 # Inference

-## Contents
-
- [KV Cache](#kv-cache)
- [KVCache System](#kvcache-system)
- [Continuous Batching](#continuous-batching)
- [Sampling](#sampling-strategy-pattern)
- [Protocol Handlers](#protocol-handlers-strategy-pattern)
- [Engine & GenerateResult](#engine--generateresult)
- [HTTP API](#http-api) — endpoints, SSE, errors, stats
- [Engine API](#engine-api)
-
 ## KV Cache

 At decode time, only the last query token matters. All previous K/V are cached to avoid recomputation:
@@ -23,72 +12,54 @@ RoPE is applied **before** KV cache write, not after — otherwise position enco

 ## KVCache System

-Seven classes working together, with two concrete cache implementations:
-
-### ContiguousCache (default)
+Six classes working together:

 ```
-ContiguousCache (simple contiguous per-slot cache)
-  ├── ContiguousCacheView  bundles k/v tensors + slot indices for attention layers
+KVCache (facade)
+  ├── Allocator        bitmask-based page allocator + ref-count + LRU eviction
+  ├── PrefixCache      hash-based prefix matching (page_hash via rolling hash)
+  ├── PagePool         orchestrates Allocator + PrefixCache
+  ├── TaskTable        maps task_id → page_table + cached token count
+  ├── Storage          k_cache / v_cache tensors (n_layers × n_pages × page_size × n_kv_heads × head_dim)
+  └── KvcacheView      bundles Storage + page_table + total_len for attention layers
 ```

-Created by default when no cache is passed to `InferenceScheduler`. Each task occupies a fixed slot of `[max_seq_len, num_key_value_heads, head_dim]`. Simple and efficient for small-to-medium batch sizes.
-
-### PageCache (paged with prefix sharing)
-
-```
-PageCache (paged KV cache with prefix sharing, alternative)
-  ├── PagePool               orchestrates page allocation + prefix matching
-  │     ├── Allocator         bitmask-based page allocator + ref-count + LRU
-  │     └── PrefixCache       hash-based prefix matching (page_hash via polynomial hash)
-  ├── TaskTable              maps task_id → page_table + cached token count
-  ├── Storage                k_cache / v_cache tensors (num_hidden_layers × n_pages × page_size × num_key_value_heads × head_dim)
-  └── PageCacheView          bundles Storage + page_table + total_len for attention layers
-```
-
-`isinstance(cache, KVCache)` checks dispatch to the correct view. Both implement the abstract `KVCache` interface used by `Executor` and `InferenceScheduler`.
+`KVCache.bind(page_table, total_len)` returns a `KvcacheView` used by attention layers via `write()` / `gather()`.

 ## Continuous Batching

 `InferenceScheduler` runs a daemon thread with a 4-phase loop:

 ```
-1. Cleanup → Remove finished tasks, free KV cache slots/pages
-2. Refill  → Pop from waiting_queue, task_alloc resources, activate
+1. Cleanup → Remove finished tasks, free KV pages
+2. Refill  → Pop from waiting_queue, task_alloc pages, activate
 3. Prefill → Group by (prompt_len, start_pos), run full forward
-4. Decode  → Run single-token forward for each same-position group
+4. Decode  → Pick largest same-position group, single-token forward
 ```

 ## Sampling (Strategy Pattern)

 ```
-BaseSamplingStrategy (ABC)
-  ├── TemperatureStrategy
-  ├── TopKStrategy
-  ├── TopPStrategy
-  └── SamplingPipeline
+BaseSamplingStrategy → TemperatureStrategy → TopKStrategy → TopPStrategy
 ```

 `SamplingPipeline` composes them: Temperature → Top-K → Top-P → softmax → multinomial.  
 `sample()` is a convenience shortcut for one-shot usage.

-## Protocol Handlers (Strategy Pattern)
+## Protocol Handlers (Template Method)

 ```python
-class ProtocolHandler:  # concrete orchestrator
-    def __init__(self, request, engine, builder): ...
-    async def handle(self):
-        prompt, ctx, stops = builder.prepare(request, engine)
+class ProtocolHandler(ABC):
+    def handle(self):
+        ctx = StreamContext(...)
        agen = engine.generate_async(prompt, ...)
-        if stream: self._handle_stream(agen, ctx, stops)
-        else:      return await self._handle_non_stream(agen, ctx, stops)
+        if stream: self._handle_stream(agen, ctx)
+        else:      self._handle_non_stream(agen, ctx)
 ```

-`ResponseBuilder` (ABC): `prepare()`, `format_stream_start()`, `format_chunk()`, `format_stream_end()`, `format_response()`.
+Subclass hooks: `build_prompt()`, `create_response_id()`, `format_stream_start/token/end()`, `format_non_stream_response()`.

-`OpenAIResponseBuilder` → `/v1/chat/completions`, `AnthropicResponseBuilder` → `/v1/messages`.
-
-Adding a protocol = one builder file, no handler subclassing needed.
+`OpenAIHandler` → `/v1/chat/completions`, `AnthropicHandler` → `/v1/messages`.

 ## Engine & GenerateResult

@@ -96,9 +67,7 @@ Adding a protocol = one builder file, no handler subclassing needed.
 InferenceEngine
  ├── generate(prompt, stream, ...) → str | List[str] | Generator
  ├── generate_with_request(req)    → same
-  ├── generate_async(prompt, ...)   → AsyncGenerator
-  ├── get_stats()                   → Dict
-  └── shutdown()
+  └── generate_async(prompt, ...)   → AsyncGenerator
 ```

 `GenerateResult` uses `Condition` for non-streaming (`wait_completion()`) and `Event` for streaming (`wait()`). Stream callback is `cb(token)`.
@@ -125,14 +94,12 @@ Response:
 {
  "id": "chatcmpl-abc123",
  "object": "chat.completion",
-  "created": 1717000000,
-  "model": "astrai",
-  "choices": [{"index": 0, "message": {"role": "assistant", "content": "Hello!"}, "finish_reason": "stop"}],
+  "choices": [{"message": {"role": "assistant", "content": "Hello!"}, "finish_reason": "stop"}],
  "usage": {"prompt_tokens": 5, "completion_tokens": 10, "total_tokens": 15}
 }
 ```

-Streaming SSE: `object: "chat.completion.chunk"` — starts with role delta, then token chunks, ends with finish chunk + usage stats, then `data: [DONE]`.
+Streaming SSE: `data: {"choices":[{"delta":{"role":"assistant"}}]}` → token chunks → `data: [DONE]`

 ### Anthropic

@@ -149,90 +116,12 @@ Supports `stop_sequences` and streaming via `event: content_block_delta`.
 | Param | Type | Default | Description |
 |-------|------|---------|-------------|
 | `messages` | List[dict] | required | Chat messages (role, content) |
-| `top_k` | int | 50 | Top-k count |
+| `temperature` | float | 1.0 | Sampling temperature (0.0–2.0) |
 | `top_p` | float | 1.0 | Nucleus threshold |
-| `temperature` | float | 1.0 | Sampling temperature (> 0.0) |
-| `max_tokens` | Optional[int] | None | Max generation length |
+| `top_k` | int | 50 | Top-k count |
+| `max_tokens` | int | None | Max generation length |
 | `stream` | bool | False | Stream output |

-### SSE Streaming Format
-
-**OpenAI** (`/v1/chat/completions`, `stream=true`):
-
-```
-data: {"id":"chatcmpl-...","object":"chat.completion.chunk","created":...,"model":"astrai",
-       "choices":[{"index":0,"delta":{"role":"assistant"},"finish_reason":null}]}
-
-data: {"id":"chatcmpl-...","object":"chat.completion.chunk","created":0,"model":"astrai",
-       "choices":[{"index":0,"delta":{"content":"Hello"},"finish_reason":null}]}
-
-data: {"id":"chatcmpl-...","object":"chat.completion.chunk","created":...,"model":"astrai",
-       "choices":[{"index":0,"delta":{},"finish_reason":"stop"}]}
-
-data: {"prompt_tokens":5,"completion_tokens":1,"total_tokens":6}
-
-data: [DONE]
-```
-
-**Anthropic** (`/v1/messages`, `stream=true`):
-
-```
-event: message_start
-data: {"type":"message_start","message":{"id":"msg_...","model":"astrai","role":"assistant",
-       "content":[],"usage":{"input_tokens":0}}}
-
-event: content_block_start
-data: {"type":"content_block_start","index":0,"content_block":{"type":"text","text":""}}
-
-event: content_block_delta
-data: {"type":"content_block_delta","index":0,"delta":{"type":"text_delta","text":"Hello"}}
-
-event: content_block_stop
-data: {"type":"content_block_stop","index":0}
-
-event: message_delta
-data: {"type":"message_delta","delta":{"stop_reason":"end_turn","stop_sequence":null},"usage":{...}}
-
-event: message_stop
-data: {"type":"message_stop"}
-```
-
-### Error Responses
-
-The server returns standard HTTP status codes. Pydantic validation errors (e.g. missing required fields)
-are handled automatically by FastAPI with 422 status. The only application-level error is engine initialization:
-
-| Status | Meaning |
-|--------|---------|
-| 200 | Success |
-| 422 | Unprocessable entity (Pydantic validation) |
-| 503 | Service unavailable (model not loaded, engine not ready) |
-
-Error response body (503):
-
-```json
-{
-    "detail": "Engine not initialized"
-}
-```
-
-### Stats Endpoint
-
-```
-GET /stats
-```
-
-Response:
-
-```json
-{
-    "total_tasks": 128,
-    "total_tokens": 10240,
-    "active_tasks": 3,
-    "waiting_queue": 2
-}
-```
-
 ## Engine API

 ```python
@@ -245,8 +134,7 @@ engine.generate("Hello", stream=True)           # -> Generator[str]
 engine.generate(["A", "B"], stream=True)        # -> Generator[Tuple[int, str]]

 # Async
-async for token in engine.generate_async("Hello", ...):    # -> AsyncGenerator[str]
-    print(token)
+await engine.generate_async("Hello", ...)       # -> AsyncGenerator[str]
 ```

-> Document Update Time: 2026-07-09
+> Document Update Time: 2026-05-17
@@ -1,11 +1,4 @@
-# CLI Parameter Reference
-
-## Contents
-
- [Training Parameters](#training-parameters)
- [Inference Server](#inference-server-serverpy)
- [Generate](#generate-generatepy)
- [Preprocess](#preprocess-preprocesspy)
+# Parameter Documentation

 ## Training Parameters

@@ -13,7 +6,7 @@

 | Parameter | Description | Default |
 |-----------|-------------|---------|
-| `--train_type` | Training type (`seq`, `sft`, `dpo`, `grpo`, `online_grpo`, `online_dpo`) | required |
+| `--train_type` | Training type (`seq`, `sft`, `dpo`, `grpo`) | required |
 | `--data_root_path` | Dataset root directory | required |
 | `--param_path` | Model parameters or checkpoint path | required |
 | `--n_epoch` | Total training epochs | 1 |
@@ -26,25 +19,21 @@
 |-----------|-------------|---------|
 | `--warmup_ratio` | Fraction of total steps used for LR warmup | 0.05 |
 | `--max_lr` | Maximum learning rate (cosine decay after warmup) | 3e-4 |
-| `--max_grad_norm` | Maximum gradient norm for clipping (None disables) | 1.0 |
+| `--max_grad_norm` | Maximum gradient norm for clipping | 1.0 |

-### Optimizer (MuonMix)
-
-Combined optimizer: matrix parameters via **Muon**, non-matrix via **AdamW** (`fused=True`).
+### Optimizer (AdamW)

 | Parameter | Description | Default |
 |-----------|-------------|---------|
-| `--weight_decay` | Weight decay (applied to Muon matrix params; non-matrix use 0) | 0.1 |
-| `--muon_momentum` | Muon momentum factor | 0.95 |
-| `--muon_nesterov` | Enable Nesterov momentum for Muon | True |
-| `--muon_ns_steps` | Newton-Schulz iteration steps for Muon | 5 |
-| `--muon_adjust_lr` | Muon LR adjustment strategy (`original`, `match_rms_adamw`) | `match_rms_adamw` |
+| `--adamw_beta1` | AdamW beta1 | 0.9 |
+| `--adamw_beta2` | AdamW beta2 | 0.95 |
+| `--adamw_weight_decay` | AdamW weight decay | 0.01 |

 ### Data Loading

 | Parameter | Description | Default |
 |-----------|-------------|---------|
-| `--window_size` | Max input sequence length | model config `max_position_embeddings` |
+| `--window_size` | Max input sequence length | model config `max_len` |
 | `--stride` | Stride for sliding window over sequences | None |
 | `--random_seed` | Random seed for reproducibility | 3407 |
 | `--num_workers` | DataLoader worker processes | 4 |
@@ -57,75 +46,27 @@ Combined optimizer: matrix parameters via **Muon**, non-matrix via **AdamW** (`f
 | `--ckpt_interval` | Iterations between checkpoints | 5000 |
 | `--ckpt_dir` | Checkpoint save directory | checkpoint |
 | `--start_epoch` | Resume from epoch (0 = from scratch) | 0 |
-| `--start_samples` | Resume from sample count per rank | 0 |
-
-### Validation
-
-| Parameter | Description | Default |
-|-----------|-------------|---------|
-| `--val_split` | Ratio to split from training dataset for validation (e.g. 0.05) | None |
-| `--val_step` | Number of optimizer steps between validation runs | 1000 |
-
-### Logging
-
-| Parameter | Description | Default |
-|-----------|-------------|---------|
-| `--log_dir` | Directory for metric logs | checkpoint/logs |
-| `--metrics` | Metrics to log (e.g. --metrics loss lr val_loss) | ["loss", "lr", "grad_norm"] |
-
-### Gradient Checkpointing
-
-| Parameter | Description | Default |
-|-----------|-------------|---------|
-| `--gradient_checkpointing` | Enable activation checkpointing for DecoderBlock modules | False |
+| `--start_batch` | Resume from batch iteration | 0 |

 ### Distributed Training

 | Parameter | Description | Default |
 |-----------|-------------|---------|
 | `--nprocs` | Number of GPUs / processes | 1 |
-| `--parallel_mode` | Parallel strategy (`none`, `ddp`, or `fsdp`) | none |
+| `--parallel_mode` | Parallel strategy (`none` or `ddp`) | none |
 | `--device_type` | Device type | cuda |
 | `--start_method` | Multiprocessing start method (`spawn`, `fork`, `forkserver`) | spawn |
-| `--backend` | Distributed training backend | nccl |
-| `--master_addr` | Master node address | localhost |
-| `--master_port` | Master node port | 29500 |

 ### Strategy-specific

 | Parameter | Description | Default | Used by |
 |-----------|-------------|---------|---------|
 | `--dpo_beta` | DPO beta value | 0.1 | `dpo` |
-| `--label_smoothing` | Label smoothing for cross-entropy loss | 0.0 | `seq`, `sft` |
+| `--label_smoothing` | Label smoothing for cross-entropy loss | 0.05 | `seq`, `sft` |
 | `--group_size` | GRPO group size | 4 | `grpo` |
 | `--grpo_clip_eps` | GRPO clipping epsilon | 0.2 | `grpo` |
 | `--grpo_kl_coef` | GRPO KL penalty coefficient | 0.01 | `grpo` |
-| `--neftune_alpha` | NEFTune noise alpha (0=disabled, typical: 5.0) | 0.0 | `sft` |
-
-### Online Rollout
-
-These options apply to `online_grpo` and `online_dpo`. Online strategies require
-a `BaseRewardModel` factory in `TrainConfig`; `train.py` does not currently
-provide a command-line option for configuring one.
-
-| Parameter | Description | Default |
-|-----------|-------------|---------|
-| `--rollout_interval` | Optimizer steps between rollout refreshes | 512 |
-| `--rollout_temperature` | Rollout sampling temperature | 0.7 |
-| `--rollout_top_k` | Rollout top-k filtering (`0` disables) | 0 |
-| `--rollout_top_p` | Rollout nucleus sampling threshold | 0.9 |
-| `--rollout_max_tokens` | Maximum generated tokens per response | 1024 |
-
-### Scheduler
-
-| Parameter | Description | Default |
-|-----------|-------------|---------|
-| `--schedule_type` | LR scheduler type (`cosine`, `sgdr`, `wsd`) | cosine |
-| `--min_rate` | Minimum LR as fraction of base LR | None (scheduler default: 0.05 for cosine/SGDR, 0.0 for WSD) |
-| `--cycle_length` | SGDR first cycle length in steps | None (total_steps - warmup_steps) |
-| `--t_mult` | SGDR cycle length multiplier per restart | 2 |
-| `--stable_steps` | WSD stable plateau steps | None (80% of post-warmup steps) |
-| `--decay_steps` | WSD decay steps | None (total_steps - warmup_steps - stable_steps) |
+| `--grpo_sync_interval` | GRPO ref_model sync interval (steps) | 200 | `grpo` |

 ### Usage Example

@@ -134,7 +75,6 @@ export CUDA_VISIBLE_DEVICES=0,1,2,3

 nohup python scripts/tools/train.py \
    --nprocs=4 \
-    --parallel_mode=ddp \
    --train_type=seq \
    --data_root_path=/path/to/dataset \
    --param_path=/path/to/model \
@@ -143,7 +83,9 @@ nohup python scripts/tools/train.py \
    --warmup_ratio=0.05 \
    --max_lr=1e-4 \
    --max_grad_norm=1.0 \
-    --weight_decay=0.1 \
+    --adamw_beta1=0.9 \
+    --adamw_beta2=0.95 \
+    --adamw_weight_decay=0.01 \
    --window_size=2048 \
    --ckpt_interval=10000 \
    --ckpt_dir=./checkpoint \
@@ -154,64 +96,4 @@ nohup python scripts/tools/train.py \

 ---

-## Inference Server (`server.py`)
-
-| Parameter | Type | Default | Description |
-|-----------|------|---------|-------------|
-| `--host` | str | `0.0.0.0` | Host address |
-| `--port` | int | `8000` | Port number |
-| `--param_path` | path | `project_root/params` | Path to model parameters |
-| `--device` | str | `cuda` | Device to load model on |
-| `--dtype` | str | `bfloat16` | Model weights dtype (`bfloat16`, `float16`, `float32`) |
-| `--max_batch_size` | int | `16` | Maximum batch size for continuous batching |
-| `--reload` | flag | `False` | Enable auto-reload for development |
-
-Usage:
-```bash
-python scripts/tools/server.py --param_path ./params --device cuda --dtype bfloat16
-```
-
-See [Inference Guide](inference.md) for HTTP API documentation.
-
-## Generate (`generate.py`)
-
-| Parameter | Type | Default | Description |
-|-----------|------|---------|-------------|
-| `--param_path` | str | required | Path to the model directory |
-| `--input_json_file` | str | required | Path to the input JSONL file |
-| `--output_json_file` | str | required | Path to the output JSONL file |
-| `--question_key` | str | `question` | Key for the question in input JSON |
-| `--response_key` | str | `response` | Key for the response in output JSON |
-| `--temperature` | float | `0.60` | Sampling temperature |
-| `--top_k` | int | `30` | Top-k filtering |
-| `--top_p` | float | `0.95` | Nucleus sampling threshold |
-| `--batch_size` | int | `1` | Batch size for generation |
-| `--max_tokens` | int | model config `max_position_embeddings` | Maximum tokens to generate |
-
-Usage:
-```bash
-python scripts/tools/generate.py \
-    --param_path ./params \
-    --input_json_file input.jsonl \
-    --output_json_file output.jsonl
-```
-
-## Preprocess (`preprocess.py`)
-
-| Parameter | Type | Default | Description |
-|-----------|------|---------|-------------|
-| `input_files` | path(s) | required | Input JSONL file(s), supports glob (`data/*.jsonl`) |
-| `--output_dir`, `-o` | path | required | Output directory for processed data |
-| `--config`, `-c` | path | required | Preprocessing pipeline config (JSON) |
-| `--tokenizer_path` | str | `params` | Path to tokenizer directory |
-
-Usage:
-```bash
-python scripts/tools/preprocess.py data/*.jsonl -o output/ -c sft.json
-```
-
-See [Preprocessing Guide](preprocessing.md) for config file format and examples.
-
---
-
-> Document Update Time: 2026-07-20
+> Document Update Time: 2026-05-24
@@ -1,364 +0,0 @@
-# Preprocessing Pipeline
-
-Declarative JSON-driven data preprocessing. `MaskBuilderFactory` supports three registered builders: `"single"` (single-output via `input.sections`), `"multi"` (multi-output via `input.sources`), and `"sectioned"` (façade dispatching to `single` or `multi` based on config).
-
-## Contents
-
- [Philosophy](#philosophy)
- [Config Structure](#config-structure)
- [Quick Start](#quick-start) — SFT Chat, SFT Instruction, Pretrain, DPO, GRPO examples
- [Configuration Reference](#configuration-reference) — all fields
- [Mask Algorithm](#mask-algorithm)
- [Output Layout](#output-layout)
- [CLI](#cli)
- [Python API](#python-api)
-
-## Philosophy
-
-| Component | Responsibility |
-|-----------|---------------|
-| `tokenizer_config.json` (`chat_template`) | Formatting -- how roles become tokens |
-| `pipeline.json` (`mask`) | Masking -- which roles participate in training |
-
-A single config file captures the entire pipeline, reusable and version-controllable.
-
-## Config Structure
-
-```json
-{
-  "version":       1,
-  "input":         {},   // sections (single) or sources (multi)
-  "mask":          {},   // role -> "train" | "mask"
-  "mask_default":  "mask",
-  "preprocessing": {},
-  "output":        {}
-}
-```
-
-### Section Fields
-
-| Field | Type | Default | Description |
-|-------|------|---------|-------------|
-| `field` | str | -- | JSONL key to read |
-| `action` | str | -- | `"train"` / `"mask"` / `"$role"` |
-| `template` | bool | `false` | Apply `chat_template` per message |
-| `add_special_tokens` | bool | `true` for first non-template section | Add special tokens during encode |
-
-### Source Fields (multi-output mode)
-
-| Field | Type | Default | Description |
-|-------|------|---------|-------------|
-| `sections` | list[dict] | -- | Same as single-output section list |
-| `list_field` | bool | `false` | JSONL field holds a list; tokenise each element |
-| `mask_key` | str | `"{key}_mask"` | Explicit output key for loss mask |
-
---
-
-## Quick Start
-
-### SFT Chat
-
-Input JSONL:
-
-```json
-{"messages": [{"role": "system", "content": "You are helpful."}, {"role": "user", "content": "Hi"}, {"role": "assistant", "content": "Hello!"}]}
-```
-
-Config:
-
-```json
-{
-  "input": {
-    "sections": [
-      {"field": "messages", "action": "$role", "template": true}
-    ]
-  },
-  "mask": {
-    "system": "mask",
-    "user": "mask",
-    "assistant": "train"
-  },
-  "mask_default": "mask",
-  "preprocessing": {
-    "max_seq_len": 2048
-  },
-  "output": {
-    "storage_format": "bin",
-    "dtype": {"loss_mask": "bool"}
-  }
-}
-```
-
-Output keys: `sequence` (int32), `loss_mask` (bool)
-
-### SFT Instruction
-
-Input JSONL:
-
-```json
-{"prompt": "Translate to French: Hello", "response": "Bonjour"}
-```
-
-Config:
-
-```json
-{
-  "input": {
-    "sections": [
-      {"field": "prompt",   "action": "mask", "add_special_tokens": true},
-      {"field": "response", "action": "train"}
-    ]
-  },
-  "mask_default": "mask",
-  "preprocessing": {
-    "max_seq_len": 2048
-  }
-}
-```
-
-Output keys: `sequence`, `loss_mask`
-
-### Pretrain
-
-Input JSONL:
-
-```json
-{"text": "Artificial Intelligence is a field of computer science..."}
-```
-
-Config:
-
-```json
-{
-  "input": {
-    "sections": [
-      {"field": "text", "action": "train"}
-    ]
-  },
-  "preprocessing": {
-    "max_seq_len": 8192,
-    "min_chars": 100
-  }
-}
-```
-
-Output keys: `sequence` (no `loss_mask` — all tokens trained)
-
-### DPO
-
-Input JSONL:
-
-```json
-{"chosen": [{"role": "user", "content": "What is 2+2?"}, {"role": "assistant", "content": "4"}], "rejected": [{"role": "user", "content": "What is 2+2?"}, {"role": "assistant", "content": "5"}]}
-```
-
-Config:
-
-```json
-{
-  "input": {
-    "sources": {
-      "chosen": {
-        "sections": [
-          {"field": "chosen", "action": "$role", "template": true}
-        ]
-      },
-      "rejected": {
-        "sections": [
-          {"field": "rejected", "action": "$role", "template": true}
-        ]
-      }
-    }
-  },
-  "mask": {
-    "user": "mask",
-    "assistant": "train"
-  },
-  "mask_default": "mask"
-}
-```
-
-Output keys: `chosen`, `chosen_mask`, `rejected`, `rejected_mask`
-
-### GRPO
-
-Input JSONL:
-
-```json
-{"prompt": [{"role": "user", "content": "What is 2+2?"}], "responses": ["4", "Five", "Four"], "rewards": [1.0, 0.3, 0.8]}
-```
-
-Config:
-
-```json
-{
-  "input": {
-    "sources": {
-      "prompts": {
-        "sections": [
-          {"field": "prompt", "action": "mask", "template": true}
-        ]
-      },
-      "responses": {
-        "sections": [
-          {"field": "responses", "action": "train"}
-        ],
-        "list_field": true,
-        "mask_key": "masks"
-      },
-      "rewards": {
-        "sections": [
-          {"field": "rewards", "action": "value"}
-        ]
-      }
-    }
-  },
-  "mask": {
-    "user": "mask",
-    "assistant": "train"
-  },
-  "mask_default": "mask"
-}
-```
-
-Output keys: `prompts`, `prompts_mask`, `responses`, `masks`, `rewards` (float32)
-
- `action: "value"` — extract raw values from JSONL without tokenisation
- `list_field: true` — tokenise each list element independently, then concatenate
- `mask_key: "masks"` — rename the auto-generated mask key (default: `responses_mask`)
- `prompts_mask` is auto-generated (all masked) and unused by GRPOStrategy
-
---
-
-## Configuration Reference
-
-### `input`
-
-| Field | Type | Default | Description |
-|-------|------|---------|-------------|
-| `sections` | list[dict] or null | `null` | Section specs for single-output mode |
-| `sources` | dict[str, dict] or null | `null` | Source specs for multi-output mode (DPO/GRPO) |
-
-When `sources` is set, `sections` is ignored.
-
-### `mask`
-
-| Field | Type | Default | Description |
-|-------|------|---------|-------------|
-| `mask` | dict | `{}` | `{role: "train" \| "mask"}` |
-| `mask_default` | str | `"mask"` | Default action for unlisted roles |
-
-### `preprocessing`
-
-| Field | Type | Default | Description |
-|-------|------|---------|-------------|
-| `max_seq_len` | int | `2048` | Truncate sequences to this length |
-| `min_chars` | int | `50` | Skip text-mode items shorter than this |
-| `max_chars` | int | `2000000` | Skip text-mode items longer than this |
-| `max_items` | int or null | `null` | Stop after N documents |
-| `packing_strategy` | str | `"simple"` | Packing strategy: `"simple"`, `"bfd"`, `"bfd_split"` |
-| `max_packed_len` | int | `8192` | Maximum length of a packed bin |
-| `truncation_mode` | str | `"keep_start"` | How to truncate sequences: `"keep_start"` or `"keep_end"` |
-
-### `output`
-
-| Field | Type | Default | Description |
-|-------|------|---------|-------------|
-| `domain_key` | str or null | `null` | JSONL key for domain grouping |
-| `storage_format` | str | `"bin"` | `"bin"` (mmap) or `"h5"` |
-| `max_tokens_per_shard` | int | `100000000` | Flush threshold in cumulative tokens |
-| `dtype` | dict[str, str] | `{}` | Per-key tensor dtype override (e.g. `{"loss_mask": "bool"}`) |
-| `position_ids_mode` | str | `"doc_reset"` | How to compute position_ids: `"none"`, `"doc_reset"`, `"continuous"` |
-
---
-
-## Mask Algorithm
-
-### Template mode (`template: true`)
-
-1. Prepend BOS token (masked)
-2. For each message in the field's array:
-   1. Render through `chat_template` for that single message
-   2. Encode rendered text
-   3. Apply mask rule for the message's role
-
-### Non-template mode
-
-Encode the field value as text. Mask value is 1 (train) or 0 (mask) per the section's `action`.
-
-### Text config detection
-
-When no section uses `template` and all sections have `action: "train"`, the builder omits `loss_mask` from the output — all tokens are trained.
-
---
-
-## Output Layout
-
-### Single-Shard (`bin`)
-
-```
-output/
-  __default__/
-    shard_0000/
-      meta.json
-      sequence.bin
-      loss_mask.bin
-  wiki/
-    shard_0000/
-      meta.json
-      sequence.bin
-      loss_mask.bin
-```
-
-### Multi-Shard (`bin`)
-
-When `max_tokens_per_shard` is exceeded:
-
-```
-output/
-  __default__/
-    shard_0000/
-      meta.json
-      sequence.bin
-      loss_mask.bin
-    shard_0001/
-      meta.json
-      sequence.bin
-      loss_mask.bin
-```
-
-For `bin` format, `MmapStore` discovers all shards under the domain directory via `rglob("meta.json")`. For `h5` format, `H5Store` discovers `.h5`/`.hdf5` files via recursive glob.
-
---
-
-## CLI
-
-```bash
-# SFT
-python scripts/tools/preprocess.py data/sft/*.jsonl -o output/sft/ -c configs/sft_chat.json
-
-# DPO
-python scripts/tools/preprocess.py data/dpo/*.jsonl -o output/dpo/ -c configs/dpo.json --tokenizer_path params
-
-# GRPO
-python scripts/tools/preprocess.py data/grpo/*.jsonl -o output/grpo/ -c configs/grpo.json
-```
-
---
-
-## Python API
-
-```python
-from astrai.preprocessing.pipeline import Pipeline
-from astrai.config.preprocess_config import PipelineConfig
-
-config = PipelineConfig.from_file("sft.json")
-Pipeline(
-    config,
-    ["data_part1.jsonl", "data_part2.jsonl"],
-    output_dir="output/",
-    tokenizer_path="params",
-).run()
-```
-
-> Document Update Time: 2026-07-09
@@ -1,17 +1,37 @@
 # Training

-## Contents
+## Model Architecture

- [Autoregression](#autoregression)
- [Causal Mask](#causal-mask)
- [Rotary Position Embedding (RoPE)](#rotary-position-embedding-rope)
- [Training Loop](#training-loop)
- [Strategies](#strategies) — SEQ, SFT, DPO, GRPO, online rollout
- [LR Schedulers](#lr-schedulers)
- [Gradient Checkpointing](#gradient-checkpointing)
- [Checkpoint](#checkpoint)
- [TrainContextBuilder](#traincontextbuilder-builder-pattern)
- [Training CLI](#training-cli)
+The model uses a decoder-only Transformer with **GQA** (Grouped Query Attention) and optional **MLA** (Multi-head Latent Attention). 1.0 billion parameters, Chinese–English bilingual.
+
+```mermaid
+flowchart TB
+    subgraph Layers["Transformer Layers"]
+        direction TB
+        A[Input Embedding] --> B[Transformer Block\nLayer 1]
+        B --> C[Transformer Block\nLayer ...]
+        C --> D[Transformer Block\nLayer ...]
+        D --> E[RMSNorm]
+        E --> F[Linear]
+        F --> G[SoftMax]
+    end
+
+    subgraph TransformerBlock["Transformer Block"]
+        direction TB
+        H[x] --> I[RMSNorm]
+        I --> J[Linear → Q/K/V]
+        J --> K[Q]; J --> L[K]; J --> M[V]
+        K --> N[RoPE]; L --> O[RoPE]
+        N --> P["Q @ K^T / sqrt(d)"]; O --> P
+        P --> Q[Masked SoftMax]; Q --> R[S @ V]; M --> R
+        R --> S[Linear]; S --> T[+]; H --> T
+        T --> U[RMSNorm]
+        U --> V["Linear (gate)"]; U --> W["Linear (up)"]
+        V --> X[SiLU]; X --> Y[×]; W --> Y
+        Y --> Z["Linear (down)"]; Z --> AA[+]; T --> AA
+        AA --> BB[x']
+    end
+```

 ### Autoregression

@@ -49,26 +69,21 @@ Two-level loop: **epoch** → **batch**. Optimizer step fires every `grad_accum_

 ```
 on_train_begin
-  model.train()
  on_epoch_begin
    for batch in dataloader:
      on_batch_begin
      with executor.accumulate(model):
-        loss = strategy.compute_loss(batch)
-        context.loss = loss.item()
-        stand_loss = loss / executor.grad_accum_steps
-        executor.backward(stand_loss)
-        context.consumed_samples += (
-            context.config.batch_per_device * context.world_size
-        )
-        on_batch_end
+        loss = strategy(batch)
+        (loss / grad_accum_steps).backward()
+        iteration += 1
+      on_batch_end

-        if executor.sync_gradients:
-          on_optimizer_step
-          optimizer.step()
-          optimizer.zero_grad()
-          if scheduler:
-            scheduler.step()
+      if executor.sync_gradients:
+        on_optimizer_step
+        optimizer.step()
+        optimizer.zero_grad()
+
+      scheduler.step()  # called every iteration
    on_epoch_end
 on_train_end
 ```
@@ -78,15 +93,11 @@ on_train_end
 | Hook | Fires | Default callback |
 |------|-------|-----------------|
 | `on_train_begin` | Before training starts | `GradientCheckpointingCallback` |
-| `on_epoch_begin` | Start of each epoch | `ProgressBarCallback` |
-| `on_batch_begin` | Every batch | — |
-| `on_optimizer_step` | Every accumulation window | `GradientClippingCallback`, `MetricCallback`, `ProgressBarCallback` |
-| `on_batch_end` | Every batch | `CheckpointCallback` |
-| `on_epoch_end` | End of each epoch | `MetricCallback`, `ProgressBarCallback` |
-| `on_error` | On exception during training | `CheckpointCallback`, `MetricCallback` |
-| `on_train_end` | Training ends (always via finally) | `CheckpointCallback`, `MetricCallback`, `GradientCheckpointingCallback` |
+| `on_optimizer_step` | Every accumulation window | `GradientClippingCallback`, `ValidationCallback` |
+| `on_batch_end` | Every batch | `CheckpointCallback`, `MetricLoggerCallback`, `ProgressBarCallback` |
+| `on_train_end` | Training ends | `CheckpointCallback`, `MetricLoggerCallback` (final save) |

-Default callbacks (in order): `gradient_checkpointing` (activation checkpointing, optional), `checkpoint` (safetensors, rank-0), `metric` (JSONL + validation, rank-0), `progress_bar` (tqdm), `gradient_clipping` (always registered; computes grad norm, clips only when `max_grad_norm` is not `None`).
+Default callbacks (in order): `gradient_checkpointing` (activation checkpointing, optional), `checkpoint` (safetensors, rank-0), `metric_logger` (JSONL, rank-0), `progress_bar` (tqdm), `gradient_clipping`, `validation` (periodic validation on val_dataset).

 ## Strategies

@@ -98,7 +109,7 @@ $$
 L_{\text{PT}} = -\sum_{t=1}^{T} \log P(x_t \mid x_{\lt t}; \theta)
 $$

-Keys: `input_ids`, `target_ids`. Optional: `label_smoothing`.
+Keys: `input_ids`, `target_ids`

 ### SFT (Supervised Fine-Tuning)

@@ -108,7 +119,7 @@ $$
 L_{\text{SFT}} = -\sum_{t=P+1}^{P+L} \log P(s_t \mid s_{\lt t}; \theta)
 $$

-Keys: `input_ids`, `target_ids`, `loss_mask`, `position_ids`. Optional: `label_smoothing`.
+Keys: `input_ids`, `target_ids`, `loss_mask`

 ### DPO (Direct Preference Optimization)

@@ -118,56 +129,32 @@ $$
 L_{\text{DPO}} = -\mathbb{E}\left[\log\sigma\left(\beta\log\frac{\pi_\theta(y_w\mid x)}{\pi_{\text{ref}}(y_w\mid x)} - \beta\log\frac{\pi_\theta(y_l\mid x)}{\pi_{\text{ref}}(y_l\mid x)}\right)\right]
 $$

-Parameters: `beta=0.1`, `reduction="sum"`. Keys: `chosen`, `rejected`, `chosen_mask`, `rejected_mask`.
+Parameters: `beta=0.1`. Keys: `chosen`, `rejected`, `chosen_mask`, `rejected_mask`.

 ### GRPO (Group Relative Policy Optimization)

-Token-level PPO with group-normalized advantages. Advantages are derived from
-scalar per-response rewards, group-normalized, and broadcast across all response
-tokens. Only response tokens contribute to the loss (prompt tokens are masked
-out):
+On-policy PPO with group-normalized advantages:

 $$
 \text{Advantage}_i = \frac{r_i - \mu}{\sigma + \epsilon}
 $$

 $$
-L_{\text{GRPO}} = -\mathbb{E}_t\left[\min\left(\rho_t A,\; \text{clip}\left(\rho_t, 1-\epsilon, 1+\epsilon\right)A\right)\right] + \lambda \cdot \mathbb{E}_t\left[\frac{\pi_{\text{ref}}}{\pi_\theta} - \log\frac{\pi_{\text{ref}}}{\pi_\theta} - 1\right]
+L_{\text{GRPO}} = -\mathbb{E}\left[\min\left(\frac{\pi_\theta}{\pi_{\text{ref}}}A,\; \text{clip}\left(\frac{\pi_\theta}{\pi_{\text{ref}}}, 1-\epsilon, 1+\epsilon\right)A\right)\right] + \lambda \cdot \mathbb{E}\left[(\log\pi_\theta - \log\pi_{\text{ref}})^2\right]
 $$

-where $\rho_t = \pi_\theta(a_t|s_t) / \pi_{\text{old}}(a_t|s_t)$ is the
-per-token importance sampling ratio against the behaviour policy
-(`old_model`, synced externally between data-generation rounds) and the
-expectations are over valid response tokens. The KL term regularises
-$\pi_\theta$ towards a frozen reference model (`ref_model`, typically
-the SFT checkpoint).
-
-Parameters: `group_size=4`, `clip_eps=0.2`, `kl_coef=0.01`. External sync of `old_model` weights via `sync_old_model()` between data-generation rounds.
+Parameters: `group_size=4`, `clip_eps=0.2`, `kl_coef=0.01`, `sync_interval=200`.

 Keys: `prompts`, `responses`, `masks`, `rewards`.

-### Online Rollout
-
-`online_grpo` and `online_dpo` use the respective GRPO and DPO strategies with
-a `RolloutRunner`. The runner renders prompts through the tokenizer chat
-template, generates grouped responses through `InferenceScheduler`, then scores
-them with a `BaseRewardModel`. It refreshes cached rollouts every
-`rollout_interval` optimizer steps. `online_grpo` synchronizes `old_model` when
-a fresh rollout is produced.
-
-Online strategies require `TrainConfig.reward_model_fn`. `train.py` exposes the
-rollout sampling parameters but does not yet offer a CLI argument for the reward
-model factory.
-
 ## LR Schedulers

 | Type | Class | Description |
 |------|-------|-------------|
 | Cosine | `CosineScheduler` | Linear warmup → cosine decay to `min_rate` |
 | SGDR | `SGDRScheduler` | Cosine annealing with warm restarts (`t_mult=2`) |
-| WSD | `WSDScheduler` | Warmup-Stable-Decay with sqrt cooldown |

-Created by `SchedulerFactory.create(schedule_type, optimizer, **kwargs)`. Valid types: `"cosine"`, `"sgdr"`, `"wsd"`. Omit to use no scheduler.
+Created by `SchedulerFactory.create(optimizer, schedule_type, **kwargs)`.

 ## Gradient Checkpointing

@@ -175,7 +162,6 @@ Trades compute for memory by recomputing activations during backward pass. Speci

 ```python
 from astrai.model.components.decoder_block import DecoderBlock
-
 config = TrainConfig(..., gradient_checkpointing_modules=[DecoderBlock])
 ```

@@ -184,26 +170,30 @@ Callback wraps each `DecoderBlock.forward` with `torch.utils.checkpoint.checkpoi
 ## Checkpoint

 ```
-Checkpoint(state_dict, epoch, consumed_samples, extra, meta, config)
-  ├── save(save_dir)    rank-0 only: meta.json (epoch/consumed_samples/timestamp) + config.json (model config) + model.safetensors + optional {key}.pt (optimizer.pt, scheduler.pt)
-  └── load(save_dir, broadcast=False)    loads from local disk; set broadcast=True to broadcast metadata from rank-0
+Checkpoint(state_dict, epoch, iteration, extra, meta)
+  ├── save(save_dir)    rank-0 only: meta.json (includes training config) + state_dict.safetensors + optional optimizer.pt / scheduler.pt
+  └── load(save_dir)    broadcasts metadata from rank-0
 ```

 Optimizer/scheduler state persisted by default via `Checkpoint.extra`.  
-Model config (`context.model_config`) saved into `config.json` during training via `CheckpointCallback`.
+Training config (`TrainConfig.to_dict()`) saved into `meta.json` during training via `CheckpointCallback`.

 ## TrainContextBuilder (Builder Pattern)

 ```python
-context = TrainContextBuilder(config).with_param_path(param_path, resume=True).build()
+context = (
+    TrainContextBuilder(config)
+        .with_checkpoint(checkpoint)
+        .build()
+)
 # Returns TrainContext with model, strategy, optimizer, scheduler, dataloader, checkpoint
 ```

- Loads checkpoint weights before the model is wrapped
- Creates executor via `ExecutorFactory.create(cfg.parallel_mode, grad_accum_steps=cfg.grad_accum_steps, **cfg.executor_kwargs)`
- Calls `executor.prepare(model_fn, optimizer_fn, scheduler_fn, before_wrap=...)`; the executor creates, wraps, then builds the optimizer and scheduler for the wrapped model
- Creates `RDSampler` for shuffle+resume
- Builds strategy via `StrategyFactory.create(train_type, model, device, **kwargs)`
+- Loads checkpoint weights if provided
+- Creates executor via `ExecutorFactory.create(parallel_mode, **executor_kwargs)`
+- Calls `executor.prepare(model, optimizer, dataloader, scheduler)` for model distribution (e.g. DDP) + gradient accumulation wrappers
+- Creates `ResumableDistributedSampler` for shuffle+resume
+- Builds strategy via `StrategyFactory.create(train_type, ...)`

 ## Training CLI

@@ -212,7 +202,6 @@ export CUDA_VISIBLE_DEVICES=0,1,2,3

 nohup python scripts/tools/train.py \
    --nprocs=4 \
-    --parallel_mode=ddp \
    --train_type=seq \
    --data_root_path=/path/to/dataset \
    --param_path=/path/to/model \
@@ -221,7 +210,9 @@ nohup python scripts/tools/train.py \
    --warmup_ratio=0.05 \
    --max_lr=1e-4 \
    --max_grad_norm=1.0 \
-    --weight_decay=0.1 \
+    --adamw_beta1=0.9 \
+    --adamw_beta2=0.95 \
+    --adamw_weight_decay=0.01 \
    --window_size=2048 \
    --ckpt_interval=10000 \
    --ckpt_dir=./checkpoint \
@@ -232,4 +223,4 @@ nohup python scripts/tools/train.py \

 Full parameter reference at [params.md](params.md).

-> Document Update Time: 2026-07-20
+> Document Update Time: 2026-05-24
@@ -1,98 +1,34 @@
-__version__ = "1.3.11"
+__version__ = "1.3.6"
 __author__ = "ViperEkura"

 from astrai.config import (
    AutoRegressiveLMConfig,
-    BaseModelConfig,
-    ConfigFactory,
    EncoderConfig,
-    PipelineConfig,
    TrainConfig,
 )
-from astrai.dataset import (
-    BaseDataset,
-    DatasetFactory,
-    RDSampler,
-    Store,
-    StoreFactory,
-)
+from astrai.dataset import DatasetFactory
 from astrai.factory import BaseFactory
 from astrai.inference import (
    GenerationRequest,
    InferenceEngine,
-    ProtocolHandler,
-    SamplingPipeline,
-    get_app,
-    run_server,
-    sample,
-)
-from astrai.model import (
-    AutoModel,
-    AutoRegressiveLM,
-    EmbeddingEncoder,
-    LoRAConfig,
-    inject_lora,
-)
-from astrai.parallel import (
-    ExecutorFactory,
-    get_rank,
-    get_world_size,
-    only_on_rank,
-    spawn_parallel_fn,
-)
-from astrai.preprocessing import Pipeline, filter_by_length
-from astrai.serialization import Checkpoint
-from astrai.tokenize import AutoTokenizer, ChatTemplate
-from astrai.trainer import (
-    BaseScheduler,
-    BaseStrategy,
-    CallbackFactory,
-    SchedulerFactory,
-    StrategyFactory,
-    TrainCallback,
-    Trainer,
 )
+from astrai.model import AutoModel, AutoRegressiveLM
+from astrai.tokenize import AutoTokenizer
+from astrai.trainer import CallbackFactory, SchedulerFactory, StrategyFactory, Trainer

 __all__ = [
    "AutoRegressiveLM",
    "AutoRegressiveLMConfig",
-    "AutoModel",
-    "AutoTokenizer",
-    "BaseDataset",
-    "BaseFactory",
-    "BaseModelConfig",
-    "BaseScheduler",
-    "BaseStrategy",
-    "CallbackFactory",
-    "ChatTemplate",
-    "Checkpoint",
-    "ConfigFactory",
-    "DatasetFactory",
-    "EmbeddingEncoder",
    "EncoderConfig",
-    "ExecutorFactory",
+    "TrainConfig",
+    "DatasetFactory",
+    "AutoTokenizer",
    "GenerationRequest",
    "InferenceEngine",
-    "LoRAConfig",
-    "Pipeline",
-    "PipelineConfig",
-    "ProtocolHandler",
-    "RDSampler",
-    "SamplingPipeline",
-    "SchedulerFactory",
-    "Store",
-    "StoreFactory",
-    "StrategyFactory",
-    "TrainCallback",
-    "TrainConfig",
    "Trainer",
-    "filter_by_length",
-    "get_app",
-    "get_rank",
-    "get_world_size",
-    "inject_lora",
-    "only_on_rank",
-    "run_server",
-    "sample",
-    "spawn_parallel_fn",
+    "CallbackFactory",
+    "StrategyFactory",
+    "SchedulerFactory",
+    "BaseFactory",
+    "AutoModel",
 ]
@@ -4,22 +4,13 @@ from astrai.config.model_config import (
    ConfigFactory,
    EncoderConfig,
 )
-from astrai.config.preprocess_config import (
-    InputConfig,
-    OutputConfig,
-    PipelineConfig,
-    ProcessingConfig,
-)
 from astrai.config.train_config import TrainConfig

 __all__ = [
+    # Model configuration
    "BaseModelConfig",
    "AutoRegressiveLMConfig",
    "EncoderConfig",
    "ConfigFactory",
    "TrainConfig",
-    "InputConfig",
-    "OutputConfig",
-    "PipelineConfig",
-    "ProcessingConfig",
 ]
@@ -1,7 +1,6 @@
 import json
 from dataclasses import MISSING, dataclass, fields
-from pathlib import Path
-from typing import Any, Dict, Optional, Self, Union, get_type_hints
+from typing import Any, Dict, Optional, Self, get_type_hints


@dataclass
@@ -14,21 +13,12 @@ class BaseConfig:
                d[fld.name] = v
            elif v is None:
                d[fld.name] = None
-            elif isinstance(v, (dict, list, tuple)):
+            elif isinstance(v, (dict, list)):
                try:
-                    val = list(v) if isinstance(v, tuple) else v
-                    json.dumps(val)
-                    d[fld.name] = val
+                    json.dumps(v)
+                    d[fld.name] = v
                except (TypeError, ValueError):
                    pass
-            elif isinstance(v, BaseConfig):
-                d[fld.name] = v.to_dict()
-            elif hasattr(v, "__dataclass_fields__"):
-                sub = {}
-                for f in fields(v):
-                    a = getattr(v, f.name)
-                    sub[f.name] = list(a) if isinstance(a, tuple) else a
-                d[fld.name] = sub
        return d

    @classmethod
@@ -84,15 +74,4 @@ class BaseConfig:
            return value
        if isinstance(value, target_type):
            return value
-        if isinstance(value, dict) and issubclass(target_type, BaseConfig):
-            return target_type.from_dict(value)
        raise TypeError
-
-    @classmethod
-    def from_file(cls, path: Union[str, Path]) -> Self:
-        with open(path, "r", encoding="utf-8") as f:
-            return cls.from_dict(json.load(f))
-
-    def to_file(self, path: Union[str, Path]):
-        with open(path, "w", encoding="utf-8") as f:
-            json.dump(self.to_dict(), f, indent=2, ensure_ascii=False)
@@ -1,5 +1,6 @@
+import json
 from dataclasses import dataclass
-from typing import Any, Dict, Optional
+from typing import Any, Dict, Optional, Self

 from astrai.config.base import BaseConfig
 from astrai.factory import BaseFactory
@@ -20,7 +21,18 @@ class BaseModelConfig(BaseConfig):
    """Base config with ``model_type`` dispatch and file I/O."""

    model_type: Optional[str] = None
-    neftune_alpha: float = 0.0
+
+    @classmethod
+    def from_file(cls, config_path: str) -> Self:
+        with open(config_path, "r") as f:
+            raw: Dict[str, Any] = json.load(f)
+        return cls.from_dict(raw)
+
+    def to_file(self, config_path: str):
+        d = self.to_dict()
+        config_dict = {k: v for k, v in d.items() if v is not None}
+        with open(config_path, "w") as f:
+            json.dump(config_dict, f, indent=4)


@dataclass
@@ -29,19 +41,18 @@ class AutoRegressiveLMConfig(BaseModelConfig):
    """Configuration for autoregressive language model."""

    vocab_size: Optional[int] = None
-    hidden_size: Optional[int] = None
-    num_hidden_layers: Optional[int] = None
-    rms_norm_eps: Optional[float] = None
-    intermediate_size: Optional[int] = None
-    tie_word_embeddings: Optional[bool] = None
+    dim: Optional[int] = None
+    n_layers: Optional[int] = None
+    norm_eps: Optional[float] = None
+    dim_ffn: Optional[int] = None
+    tie_weight: Optional[bool] = None

-    max_position_embeddings: Optional[int] = None
+    max_len: Optional[int] = None
    rope_theta: Optional[float] = None
-    rope_scaling: Optional[dict] = None

    attn_type: str = "gqa"
-    num_attention_heads: Optional[int] = None
-    num_key_value_heads: Optional[int] = None
+    n_heads: Optional[int] = None
+    n_kv_heads: Optional[int] = None
    use_qk_norm: Optional[bool] = None
    use_gated_attention: Optional[bool] = None

@@ -62,21 +73,18 @@ class EncoderConfig(BaseModelConfig):
    """Configuration for embedding encoder model."""

    vocab_size: Optional[int] = None
-    hidden_size: Optional[int] = None
-    num_hidden_layers: Optional[int] = None
-    rms_norm_eps: Optional[float] = None
-    intermediate_size: Optional[int] = None
+    dim: Optional[int] = None
+    n_layers: Optional[int] = None
+    norm_eps: Optional[float] = None
+    dim_ffn: Optional[int] = None

-    max_position_embeddings: Optional[int] = None
+    max_len: Optional[int] = None
    rope_theta: Optional[float] = None
-    rope_scaling: Optional[dict] = None

-    attn_type: str = "gqa"
-    num_attention_heads: Optional[int] = None
-    num_key_value_heads: Optional[int] = None
+    n_heads: Optional[int] = None
+    n_kv_heads: Optional[int] = None
    use_qk_norm: Optional[bool] = None
    use_gated_attention: Optional[bool] = None

-    ffn_type: str = "mlp"
    pooling_type: Optional[str] = None
    normalize_embeddings: Optional[bool] = None
@@ -1,112 +0,0 @@
-"""Pipeline configuration for JSONL preprocessing.
-
-Supports single-sequence (SFT/pretrain) and multi-output (DPO/GRPO)
-modes, both driven declaratively through ``input.sections`` or
-``input.sources``.
-"""
-
-from dataclasses import dataclass, field
-from typing import Dict, List, Optional
-
-from astrai.config.base import BaseConfig
-
-
-@dataclass
-class InputConfig(BaseConfig):
-    """Declarative input mapping.
-
-    Single-output mode (backward-compatible)::
-
-        {"input": {"sections": [{"field": "messages", ...}]}}
-
-    Multi-output mode (DPO / GRPO)::
-
-        {"input": {"sources": {
-            "chosen": {"sections": [{"field": "chosen", ...}]},
-            "rejected": {"sections": [{"field": "rejected", ...}]},
-        }}}
-    """
-
-    sections: Optional[List[Dict]] = None
-    sources: Optional[Dict[str, Dict]] = None
-
-
-@dataclass
-class ProcessingConfig(BaseConfig):
-    """Processing configuration.
-
-    Parameters
-    ----------
-    max_seq_len : int
-        Maximum sequence length (default: 2048).
-    min_chars : int
-        Minimum number of characters to keep (default: 50).
-    max_chars : int
-        Maximum number of characters to keep (default: 2_000_000).
-    max_items : Optional[int]
-        Maximum number of items to process (default: None, unlimited).
-    batch_size : int
-        Number of records tokenized together (default: 256).
-    packing_strategy : str
-        How to pack sequences into a contiguous stream.
-
-        - ``"simple"``: sequential concatenation (default, backward compatible).
-        - ``"bfd"``: best-fit decreasing bin packing, minimises wasted tokens.
-        - ``"bfd_split"``: BFD with over-length sequences split into chunks.
-    max_packed_len : int
-        Maximum length of a packed bin. Sequences longer than this are
-        truncated or split depending on ``packing_strategy`` (default: 8192).
-    truncation_mode : str
-        How to truncate sequences longer than ``max_packed_len``.
-
-        - ``"keep_start"``: keep the first ``max_packed_len`` tokens (default).
-        - ``"keep_end"``: keep the last ``max_packed_len`` tokens.
-    """
-
-    max_seq_len: int = 2048
-    min_chars: int = 50
-    max_chars: int = 2_000_000
-    max_items: Optional[int] = None
-    batch_size: int = 256
-    packing_strategy: str = "simple"
-    max_packed_len: int = 8192
-    truncation_mode: str = "keep_start"
-
-
-@dataclass
-class OutputConfig(BaseConfig):
-    """Output configuration.
-
-    Parameters
-    ----------
-    domain_key : Optional[str]
-        Domain key for the output store (default: None).
-    storage_format : str
-        Storage format, one of ``"bin"``, ``"jsonl"`` (default: ``"bin"``).
-    max_tokens_per_shard : int
-        Maximum tokens per shard before splitting (default: 100_000_000).
-    dtype : Dict[str, str]
-        Per-key dtype overrides, e.g. ``{"input_ids": "int32"}`` (default: {}).
-    position_ids_mode : Optional[str]
-        How to compute position_ids in packed sequences.
-
-         - ``"none"``: do not generate (default).
-        - ``"doc_reset"``: reset to 0 at each document boundary.
-        - ``"continuous"``: sequential 0, 1, 2, ... (pretrain, single doc).
-    """
-
-    domain_key: Optional[str] = None
-    storage_format: str = "bin"
-    max_tokens_per_shard: int = 100_000_000
-    dtype: Dict[str, str] = field(default_factory=dict)
-    position_ids_mode: str = "doc_reset"
-
-
-@dataclass
-class PipelineConfig(BaseConfig):
-    version: int = 1
-    input: InputConfig = field(default_factory=InputConfig)
-    mask: Dict[str, str] = field(default_factory=dict)
-    mask_default: str = "mask"
-    preprocessing: ProcessingConfig = field(default_factory=ProcessingConfig)
-    output: OutputConfig = field(default_factory=OutputConfig)
@@ -1,5 +1,5 @@
 from dataclasses import dataclass, field, fields
-from typing import Any, Callable, Dict, List, Optional
+from typing import Callable, List, Optional

 import torch.nn as nn
 from torch.optim import Optimizer
@@ -7,7 +7,6 @@ from torch.optim.lr_scheduler import LRScheduler
 from torch.utils.data import Dataset

 from astrai.config.base import BaseConfig
-from astrai.model.components.lora import LoRAConfig


 def required(**kw):
@@ -17,8 +16,8 @@ def required(**kw):
@dataclass
 class TrainConfig(BaseConfig):
    # basic setting
-    model_fn: Callable[[], nn.Module] = field(
-        default=None, metadata=required(help="Model factory for training.")
+    model: nn.Module = field(
+        default=None, metadata=required(help="Model for training.")
    )
    strategy: str = field(default=None, metadata=required(help="Training strategy."))
    dataset: Dataset = field(
@@ -37,43 +36,36 @@ class TrainConfig(BaseConfig):
    grad_accum_steps: int = field(
        default=1, metadata={"help": "Number of iterations between steps."}
    )
-    max_grad_norm: Optional[float] = field(
-        default=1.0,
-        metadata={"help": "Maximum gradient norm. None disables clipping."},
+    max_grad_norm: float = field(
+        default=1.0, metadata={"help": "Maximum gradient norm."}
    )
-    gradient_checkpointing_modules: List[str] = field(
+    gradient_checkpointing_modules: list = field(
        default_factory=list,
        metadata={"help": "Module types to enable activation checkpointing for."},
    )

    # checkpoint setting
    start_epoch: int = field(default=0, metadata={"help": "Start epoch for training."})
-    start_samples: int = field(
-        default=0,
-        metadata={
-            "help": "Start samples count (per rank). Superseded by checkpoint consumed_samples."
-        },
+    start_batch: int = field(
+        default=0, metadata={"help": "Start batch iteration for training."}
    )
    ckpt_dir: str = field(
        default="./checkpoint", metadata={"help": "Checkpoint directory."}
    )
    ckpt_interval: int = field(
-        default=5000,
-        metadata={"help": "Number of optimizer steps between checkpoints."},
-    )
-
-    # lora setting
-    lora: Optional[LoRAConfig] = field(
-        default=None,
-        metadata={"help": "LoRA config. None means full fine-tuning."},
+        default=5000, metadata={"help": "Number of iterations between checkpoints."}
    )

    # metric setting
    log_dir: str = field(
        default="./checkpoint/logs", metadata={"help": "Directory for metric logs."}
    )
+    log_interval: int = field(
+        default=100,
+        metadata={"help": "Number of batch iterations between metric logs."},
+    )
    metrics: List[str] = field(
-        default_factory=lambda: ["loss", "lr", "grad_norm"],
+        default_factory=lambda: ["loss", "lr"],
        metadata={"help": "Metrics to record during training."},
    )

@@ -88,10 +80,6 @@ class TrainConfig(BaseConfig):
    pin_memory: bool = field(
        default=False, metadata={"help": "Pin memory for dataloader."}
    )
-    collate_fn: Optional[Callable[[List[Any]], Any]] = field(
-        default=None,
-        metadata={"help": "Collate function for dataloader (e.g. dpo_collate_fn)."},
-    )

    # distributed training
    nprocs: int = field(
@@ -123,52 +111,16 @@ class TrainConfig(BaseConfig):
    val_dataset: Optional[Dataset] = field(
        default=None, metadata={"help": "Dataset for validation."}
    )
-    val_split: Optional[float] = field(
-        default=None,
-        metadata={
-            "help": "Ratio to split from training dataset for validation (e.g. 0.05). Ignored if val_dataset is set."
-        },
-    )
    val_step: int = field(
        default=1000,
        metadata={"help": "Number of optimizer steps between validation runs."},
    )
-    neftune_alpha: float = field(
-        default=0.0,
-        metadata={"help": "NEFTune noise alpha (0=disabled, typical: 5.0)."},
-    )

-    # online rollout
-    rollout_interval: int = field(
-        default=512,
-        metadata={"help": "Number of optimizer steps between online rollouts."},
-    )
-    rollout_temperature: float = field(
-        default=0.7, metadata={"help": "Sampling temperature for online rollout."}
-    )
-    rollout_top_k: int = field(
-        default=0, metadata={"help": "Top-k filtering for online rollout (0=disable)."}
-    )
-    rollout_top_p: float = field(
-        default=0.9,
-        metadata={"help": "Top-p (nucleus) filtering for online rollout."},
-    )
-    rollout_max_tokens: int = field(
-        default=1024,
-        metadata={"help": "Maximum generated tokens per response in rollout."},
-    )
-    reward_model_fn: Optional[Callable] = field(
-        default=None,
-        metadata={
-            "help": "Factory for reward model (required for online RL strategies)."
-        },
-    )
-
-    executor_kwargs: Dict[str, Any] = field(
+    executor_kwargs: dict = field(
        default_factory=dict,
        metadata={"help": "Extra kwargs passed to ExecutorFactory.create()."},
    )
-    extra_kwargs: Dict[str, Any] = field(
+    extra_kwargs: dict = field(
        default_factory=dict, metadata={"help": "Other arguments."}
    )

@@ -1,43 +1,35 @@
 from astrai.dataset.dataset import (
    BaseDataset,
    DatasetFactory,
-    dpo_collate_fn,
-    grpo_collate_fn,
 )
-from astrai.dataset.sampler import RDSampler
+from astrai.dataset.sampler import ResumableDistributedSampler
 from astrai.dataset.storage import (
-    H5Store,
-    JsonlStore,
-    MmapStore,
-    Recordable,
-    Store,
-    StoreFactory,
-    Streamable,
+    BaseSegmentFetcher,
+    BaseStorage,
+    H5Storage,
+    JSONStorage,
+    MultiSegmentFetcher,
+    StorageFactory,
    detect_format,
-)
-from astrai.serialization import (
-    load_bin,
    load_h5,
-    save_bin,
+    load_json,
    save_h5,
+    save_json,
 )

 __all__ = [
    "BaseDataset",
    "DatasetFactory",
-    "dpo_collate_fn",
-    "grpo_collate_fn",
-    "Store",
-    "Streamable",
-    "Recordable",
-    "StoreFactory",
-    "H5Store",
-    "MmapStore",
-    "JsonlStore",
+    "BaseSegmentFetcher",
+    "MultiSegmentFetcher",
+    "BaseStorage",
+    "H5Storage",
+    "JSONStorage",
+    "StorageFactory",
    "detect_format",
    "save_h5",
    "load_h5",
-    "save_bin",
-    "load_bin",
-    "RDSampler",
+    "save_json",
+    "load_json",
+    "ResumableDistributedSampler",
 ]
@@ -1,506 +1,319 @@
-"""Dataset implementations for training.
-
-Composition over inheritance — every dataset is a thin wrapper that
-binds a :class:`Store` to a particular train-type's key mapping.  All
-sample-id → token/record indexing lives on the Store; datasets never
-know about window/stride math or segment layouts.
-
-Class hierarchy:
-
-    BaseDataset (ABC)         — holds a Store, exposes __len__/keys,
-                                 overrides __getitem__
-    ├── SEQDataset            — next-token prediction (stream)
-    ├── SFTDataset            — loss-mask + position_ids (stream)
-    ├── DPODataset            — chosen/rejected pairs (record)
-    └── GRPODataset           — prompt + response group (record)
-
-``DatasetFactory.load(train_type, load_path, window_size, stride, …)``
-builds the Store (auto-detecting format) before constructing the
-matching dataset.  Passing ``store=`` skips Store construction.
-
-When a record dataset (DPO) reads from raw JSONL, a *processor*
-function (pure ``record -> Dict[str, Tensor]``) is forwarded to
-:class:`JsonlStore` so tokenisation happens on the fly.
-"""
+"""Dataset implementations with factory pattern for training."""

 from abc import ABC, abstractmethod
-from functools import partial
-from typing import Callable, Dict, List, Optional
+from typing import Dict, List, Optional

 import torch
 from torch import Tensor
 from torch.utils.data import Dataset

 from astrai.dataset.storage import (
-    Store,
-    StoreFactory,
+    BaseStorage,
+    StorageFactory,
    detect_format,
 )
 from astrai.factory import BaseFactory
-from astrai.tokenize import AutoTokenizer
-
-
-def dpo_tokenize(
-    record: dict,
-    tokenizer,
-    max_len: int = 2048,
-) -> Optional[dict]:
-    """Tokenize one DPO record into chosen/rejected + masks.
-
-    Applies the tokenizer's chat template so token sequences match the
-    SFT checkpoint's format.  Prompt is rendered with
-    ``add_generation_prompt=True``; chosen/rejected are appended as a
-    single assistant turn.
-
-    Accepts:
-
-    - Flat:   ``{"prompt": str, "chosen": str, "rejected": str}``
-    - Conv:   ``{"prompt": [{role, content}, ...], "chosen": [...], ...}``
-    - Legacy: ``{"input": str, "chosen": str, "rejected": str}``
-
-    No packing, no ``position_ids`` — DPO sequences are independent.
-    """
-    prompt = record.get("prompt") or record.get("input")
-    chosen = record.get("chosen")
-    rejected = record.get("rejected")
-    if prompt is None or chosen is None or rejected is None:
-        return None
-
-    prompt_messages = _to_messages(prompt)
-    chosen_text = _extract_text(chosen)
-    rejected_text = _extract_text(rejected)
-    if chosen_text is None or rejected_text is None:
-        return None
-    chosen_messages = prompt_messages + [{"role": "assistant", "content": chosen_text}]
-    rejected_messages = prompt_messages + [
-        {"role": "assistant", "content": rejected_text}
-    ]
-
-    prompt_ids = tokenizer.apply_chat_template(
-        prompt_messages, tokenize=True, add_generation_prompt=True
-    )
-    ch_ids = tokenizer.apply_chat_template(
-        chosen_messages, tokenize=True, add_generation_prompt=False
-    )
-    re_ids = tokenizer.apply_chat_template(
-        rejected_messages, tokenize=True, add_generation_prompt=False
-    )
-
-    full_ch = ch_ids[:max_len]
-    full_re = re_ids[:max_len]
-
-    prompt_len = min(len(prompt_ids), max_len)
-    ch_mask = [0] * prompt_len + [1] * max(0, len(full_ch) - prompt_len)
-    ch_mask = ch_mask[:max_len]
-    re_mask = [0] * prompt_len + [1] * max(0, len(full_re) - prompt_len)
-    re_mask = re_mask[:max_len]
-
-    return {
-        "chosen": full_ch,
-        "rejected": full_re,
-        "chosen_mask": ch_mask,
-        "rejected_mask": re_mask,
-    }
-
-
-def _to_messages(value) -> list:
-    """Accept str or conversation list; return message list."""
-    if isinstance(value, str):
-        return [{"role": "user", "content": value}]
-    if isinstance(value, list):
-        return value
-    return [{"role": "user", "content": str(value)}]
-
-
-def _extract_text(value) -> Optional[str]:
-    """Accept str or conversation list; return plain text."""
-    if value is None:
-        return None
-    if isinstance(value, str):
-        return value
-    if isinstance(value, list):
-        return "".join(m.get("content", "") for m in value if isinstance(m, dict))
-    return None
-
-
-def dpo_processor(
-    record: dict,
-    tokenizer,
-    max_len: int = 2048,
-) -> Dict[str, Tensor]:
-    """DPO processor: wraps :func:`dpo_tokenize` and returns tensors."""
-    result = dpo_tokenize(record, tokenizer, max_len=max_len)
-    if result is None:
-        raise ValueError(f"Malformed DPO record: {list(record.keys())}")
-    return {
-        "chosen": torch.tensor(result["chosen"], dtype=torch.int32),
-        "rejected": torch.tensor(result["rejected"], dtype=torch.int32),
-        "chosen_mask": torch.tensor(result["chosen_mask"], dtype=torch.bool),
-        "rejected_mask": torch.tensor(result["rejected_mask"], dtype=torch.bool),
-    }
-
-
-def dpo_collate_fn(batch: List[Dict[str, Tensor]]) -> Dict[str, Tensor]:
-    """Collate variable-length DPO samples into padded 2-D tensors.
-
-    Input: list of dicts, each with:
-      - chosen:        [C_i]
-      - rejected:      [R_i]
-      - chosen_mask:   [C_i]
-      - rejected_mask: [R_i]
-
-    Output (padded to the max length across chosen/rejected within the batch):
-      - chosen:        [B, S_max]
-      - rejected:      [B, S_max]
-      - chosen_mask:   [B, S_max]
-      - rejected_mask: [B, S_max]
-    """
-    B = len(batch)
-    S_max = max(b["chosen"].size(0) for b in batch)
-    S_max = max(S_max, max(b["rejected"].size(0) for b in batch))
-
-    chosen = torch.zeros(B, S_max, dtype=torch.long)
-    rejected = torch.zeros(B, S_max, dtype=torch.long)
-    chosen_mask = torch.zeros(B, S_max, dtype=torch.bool)
-    rejected_mask = torch.zeros(B, S_max, dtype=torch.bool)
-
-    for i, b in enumerate(batch):
-        c_len = b["chosen"].size(0)
-        r_len = b["rejected"].size(0)
-        chosen[i, :c_len] = b["chosen"]
-        rejected[i, :r_len] = b["rejected"]
-        chosen_mask[i, :c_len] = b["chosen_mask"]
-        rejected_mask[i, :r_len] = b["rejected_mask"]
-
-    return {
-        "chosen": chosen,
-        "rejected": rejected,
-        "chosen_mask": chosen_mask,
-        "rejected_mask": rejected_mask,
-    }
-
-
-def grpo_collate_fn(batch: List[Dict[str, Tensor]]) -> Dict[str, Tensor]:
-    """Collate variable-length GRPO samples into padded 3-D tensors.
-
-    Input: list of dicts, each with:
-      - prompts:  [P_i]
-      - responses: list of G tensors, each [R_ij]
-      - masks:     list of G tensors, each [R_ij]
-      - rewards:  [G]
-
-    Output:
-      - prompts:   [B, P_max], left-padded
-      - prompt_mask: [B, P_max]
-      - responses: [B, G, R_max]
-      - masks:     [B, G, R_max]
-      - rewards:   [B, G]
-    """
-    B = len(batch)
-    G = len(batch[0]["responses"])
-    P_max = max(b["prompts"].size(0) for b in batch)
-    R_max = max(r.size(0) for b in batch for r in b["responses"])
-
-    prompts = torch.zeros(B, P_max, dtype=torch.long)
-    prompt_mask = torch.zeros(B, P_max, dtype=torch.bool)
-    responses = torch.zeros(B, G, R_max, dtype=torch.long)
-    masks = torch.zeros(B, G, R_max, dtype=torch.bool)
-    rewards = torch.zeros(B, G, dtype=torch.float32)
-
-    for i, b in enumerate(batch):
-        p_len = b["prompts"].size(0)
-        prompts[i, -p_len:] = b["prompts"]
-        prompt_mask[i, -p_len:] = True
-        rewards[i, : b["rewards"].size(0)] = b["rewards"]
-        for g in range(min(G, len(b["responses"]))):
-            r_len = b["responses"][g].size(0)
-            responses[i, g, :r_len] = b["responses"][g]
-            if g < len(b["masks"]):
-                masks[i, g, :r_len] = b["masks"][g]
-
-    return {
-        "prompts": prompts,
-        "prompt_mask": prompt_mask,
-        "responses": responses,
-        "masks": masks,
-        "rewards": rewards,
-    }
-
-
-def validate_keys(store: Store, required: List[str]) -> None:
-    """Raise ``KeyError`` if *store* is missing any *required* key."""
-    if not required:
-        return
-    actual = set(store.keys)
-    missing = [k for k in required if k not in actual]
-    if missing:
-        raise KeyError(
-            f"Store at {getattr(store, '_load_path', '?')} is missing required "
-            f"keys {missing}; available keys are {sorted(actual)}."
-        )


 class BaseDataset(Dataset, ABC):
-    """Abstract base class for dataset types.
+    """Abstract base class for all dataset types.

-    Holds a :class:`Store`.  All sample-id indexing is delegated to the
-    store — this class exposes ``__len__`` as ``len(store)`` and the
-    ``keys`` property as ``store.keys``.  Subclasses implement
-    ``__getitem__`` with the train-type-specific key mapping and any
-    training-only index arithmetic (e.g. the next-token ``+1`` shift).
+    Implements common functionality for window-based data fetching.
+    Uses a storage abstraction for format-agnostic data loading.
    """

-    required_keys: List[str] = []
-
-    def __init__(self, store: Store):
+    def __init__(self, window_size: int, stride: int):
        super().__init__()
-        self.store: Store = store
-        validate_keys(store, self.required_keys)
+        self.window_size = window_size
+        self.stride = stride
+        self.storage: Optional[BaseStorage] = None

-    def __len__(self) -> int:
-        return len(self.store)
+    @property
+    def required_keys(self) -> List[str]:
+        """Return required storage keys for this dataset type.
+
+        Subclasses should override to specify expected keys.
+        """
+        return []
+
+    def _validate_keys(self):
+        if not self.required_keys:
+            return
+        actual_keys = set(self.storage.keys)
+        missing = [k for k in self.required_keys if k not in actual_keys]
+        if missing:
+            raise KeyError(
+                f"Dataset {type(self).__name__} requires keys {self.required_keys}, "
+                f"but storage at {self._load_path} only has {sorted(actual_keys)}. "
+                f"Missing: {missing}"
+            )
+
+    def load(self, load_path: str, storage_type: Optional[str] = None, tokenizer=None):
+        """Load dataset from the given path.
+
+        Auto-detects the storage format if not specified.
+
+        Args:
+            load_path: Path to the data directory or file
+            storage_type: Force a specific storage type ("h5", "json"),
+                          or None for auto-detection
+            tokenizer: Callable str -> List[int], used to tokenize raw text
+                       in JSON files. Ignored for HDF5.
+
+        Raises:
+            KeyError: If the loaded storage is missing required keys.
+        """
+        if storage_type is None:
+            storage_type = detect_format(load_path)
+        self.storage = StorageFactory.create(storage_type)
+        self._load_path = load_path
+        self.storage.load(load_path, tokenizer=tokenizer)
+        self._validate_keys()
+
+    def load_json(self, load_path: str, tokenizer=None):
+        """Load dataset from JSON files explicitly.
+
+        Args:
+            load_path: Path to the JSON data file or directory
+            tokenizer: Optional tokenizer callable for raw text JSON.
+        """
+        self.load(load_path, storage_type="json", tokenizer=tokenizer)
+
+    @property
+    def count(self) -> int:
+        """Return the total number of raw elements (tokens) in the dataset."""
+        if self.storage is None:
+            return 0
+        return len(self.storage)

    @property
    def keys(self) -> List[str]:
-        return self.store.keys
+        """Return the available data keys."""
+        if self.storage is None:
+            return []
+        return self.storage.keys

-    @property
-    def token_count(self) -> int:
-        return self.store.token_count
+    def get_index(self, index: int) -> tuple:
+        """Calculate begin and end indices for a sample.
+
+        Args:
+            index: Sample index
+
+        Returns:
+            Tuple of (begin_idx, end_idx)
+        """
+        if self.storage is None:
+            raise RuntimeError("Dataset not loaded, call load() first")
+        total = len(self.storage)
+        if total <= self.window_size:
+            raise ValueError(
+                f"Data too short: {total} tokens <= window_size {self.window_size}"
+            )
+
+        begin_idx = min(index * self.stride, total - 1 - self.window_size)
+        end_idx = min(begin_idx + self.window_size, total - 1)
+
+        return begin_idx, end_idx

    @abstractmethod
    def __getitem__(self, index: int) -> Dict[str, Tensor]:
+        """Get a single sample by index.
+
+        Must be implemented by subclasses.
+        """
        raise NotImplementedError

+    def __len__(self) -> int:
+        if self.storage is None:
+            return 0
+        total = len(self.storage)
+        if total <= self.window_size:
+            return 0
+        return (total - 1 - self.window_size) // self.stride + 1
+

 class DatasetFactory(BaseFactory["BaseDataset"]):
-    """Factory for creating dataset instances by train-type.
+    """Factory class for creating dataset instances.

-    Use :meth:`DatasetFactory.register("custom")` to register new
-    dataset classes; they must inherit from :class:`BaseDataset`.
+    Supports decorator-based registration for extensible dataset types.
+    All default dataset types (seq, sft, dpo, grpo) are registered automatically
+    when their classes are defined with the decorator.
+
+    Example usage:
+        @DatasetFactory.register("custom")
+        class CustomDataset(BaseDataset):
+            ...
+
+        dataset = DatasetFactory.create("custom", window_size, stride)
    """

+    @classmethod
+    def _validate_component(cls, dataset_cls: type) -> None:
+        """Validate that the dataset class inherits from BaseDataset."""
+        if not issubclass(dataset_cls, BaseDataset):
+            raise TypeError(f"{dataset_cls.__name__} must inherit from BaseDataset")
+
+    @classmethod
+    def create(cls, train_type: str, window_size: int, stride: int) -> "BaseDataset":
+        """Create a dataset instance.
+
+        Args:
+            train_type: Type of training ("seq", "sft", "dpo", "grpo")
+            window_size: Window size for data sampling
+            stride: Stride between consecutive samples
+
+        Returns:
+            Dataset instance
+        """
+        return super().create(train_type, window_size, stride)
+
    @classmethod
    def load(
        cls,
        train_type: str,
-        load_path: Optional[str] = None,
-        window_size: int = 0,
+        load_path: str,
+        window_size: int,
        stride: Optional[int] = None,
        storage_type: Optional[str] = None,
-        tokenizer_path: Optional[str] = None,
-        max_len: int = 2048,
-        store: Optional[Store] = None,
-        **kwargs,
+        tokenizer=None,
    ) -> "BaseDataset":
        """Create and load a dataset in one step.

-        Two entry points:
-
-        - **store given**: bind it directly — the caller fully controls
-          Store construction and processor setup.  *load_path*,
-          *storage_type*, *tokenizer_path*, *window_size*, *stride* are
-          ignored.
-        - **store is None**: build a Store from *load_path*, auto-detecting
-          format and constructing a processor when *tokenizer_path* is
-          given for a record dataset on JSONL.
-
        Args:
-            train_type: Registered dataset name ("seq", "sft", "dpo",
-                "grpo", …).
-            load_path: Path to the data file or directory (ignored if
-                *store* is given).
-            window_size: Stream window length — only meaningful for
-                stream datasets (SEQ/SFT).  Record datasets ignore it.
-            stride: Stride between consecutive stream samples
-                (default: same as *window_size*).
-            storage_type: Storage backend ("h5", "bin", "jsonl") or
-                None for auto-detection.
-            tokenizer_path: Path to tokenizer for lazy JSONL
-                tokenisation (record datasets only).
-            max_len: Max sequence length forwarded to processors.
-            store: Pre-built, already-loaded Store instance.
-            **kwargs: Extra arguments forwarded to ``store.load()``.
+            train_type: Type of training dataset
+            load_path: Path to the data file
+            window_size: Window size for data sampling
+            stride: Stride between consecutive samples (default: same as window_size)
+            storage_type: Storage type ("h5", "json") or None for auto-detection
+            tokenizer: Callable str -> List[int] for raw text JSON tokenization

        Returns:
-            Loaded dataset instance.
+            Loaded dataset instance
        """
-        if store is not None:
-            return cls.create(train_type, store=store)
-
-        if load_path is None:
-            raise ValueError("Either load_path or store must be provided")
-
-        if storage_type is None:
-            storage_type = detect_format(load_path)
-
        if stride is None:
            stride = window_size

-        processor = cls._maybe_build_processor(
-            train_type, storage_type, tokenizer_path, max_len
-        )
+        dataset = cls.create(train_type, window_size, stride)
+        dataset.load(load_path, storage_type=storage_type, tokenizer=tokenizer)

-        store_window = cls._store_window_for(train_type, window_size)
-        store = StoreFactory.create(
-            storage_type,
-            window_size=store_window,
-            stride=stride if stride else store_window,
-        )
-        if processor is not None:
-            store.load(load_path, processor=processor, **kwargs)
-        else:
-            load_kwargs = dict(kwargs)
-            if (
-                tokenizer_path is not None
-                and storage_type == "jsonl"
-                and train_type in ("seq", "sft")
-                and "tokenizer_path" not in load_kwargs
-            ):
-                load_kwargs["tokenizer_path"] = tokenizer_path
-            store.load(load_path, **load_kwargs)
+        return dataset

-        return cls.create(train_type, store=store)
-
-    @staticmethod
-    def _store_window_for(train_type: str, window_size: int) -> int:
-        """Stream datasets consume ``window_size``; record datasets ignore it.
-
-        Record datasets (dpo/grpo) treat each record as an independent
-        training unit and never window, so the store is built with
-        ``window_size=0`` and ``len(store)`` returns the record count.
-        """
-        if train_type in ("seq", "sft"):
-            return window_size
-        return 0
-
-    @staticmethod
-    def _maybe_build_processor(
-        train_type: str,
-        storage_type: str,
-        tokenizer_path: Optional[str],
-        max_len: int,
-    ) -> Optional[Callable[[dict], Dict[str, Tensor]]]:
-        """Build an on-the-fly tokenisation processor if applicable.
-
-        Only raw JSONL + record datasets (DPO/GRPO) need a processor;
-        pre-tokenised backends (H5/bin) and stream datasets (SEQ/SFT)
-        return ``None`` so no tokenizer is loaded.
-        """
-        if tokenizer_path is None or storage_type != "jsonl":
-            return None
-        if train_type == "dpo":
-            tokenizer = AutoTokenizer.from_pretrained(tokenizer_path)
-            return partial(dpo_processor, tokenizer=tokenizer, max_len=max_len)
-        return None
+    @classmethod
+    def available_types(cls) -> list:
+        """Return list of registered dataset type names."""
+        return cls.list_registered()


@DatasetFactory.register("seq")
 class SEQDataset(BaseDataset):
-    """Dataset for sequential next-token prediction training.
+    """Dataset for sequential next-token prediction training."""

-    Stream mode: ``store.fetch(begin, end, "sequence")`` returns the
-    input window; the +1 shifted call returns the next-token target.
-    """
+    def __init__(self, window_size: int, stride: int):
+        super().__init__(window_size, stride)

-    required_keys = ["sequence"]
+    @property
+    def required_keys(self) -> List[str]:
+        return ["sequence"]

-    def __getitem__(self, index: int):
-        begin, end = self.store.sample_window(index)
-        x = self.store.fetch(begin, end, "sequence")
-        y = self.store.fetch(begin + 1, end + 1, "sequence")
-        return {
-            "input_ids": x.to(dtype=torch.long),
-            "target_ids": y.to(dtype=torch.long),
-        }
+    def _fetch_data(self, begin_idx: int, end_idx: int) -> Tensor:
+        return self.storage.fetch(begin_idx, end_idx, "sequence")
+
+    def __getitem__(self, index):
+        begin_idx, end_idx = self.get_index(index)
+
+        x = self._fetch_data(begin_idx, end_idx).to(dtype=torch.long)
+        y = self._fetch_data(begin_idx + 1, end_idx + 1).to(dtype=torch.long)
+
+        return {"input_ids": x, "target_ids": y}


@DatasetFactory.register("sft")
 class SFTDataset(BaseDataset):
-    """Dataset for supervised fine-tuning with loss masking.
+    """Dataset for supervised fine-tuning with loss masking."""

-    Stream mode: ``sequence``/``loss_mask``/``position_ids`` are sliced
-    to the window.  ``loss_mask`` and ``target_ids`` use the +1 shifted
-    slice so they align with the predicted positions.
-    """
+    def __init__(self, window_size: int, stride: int):
+        super().__init__(window_size, stride)

-    required_keys = ["sequence", "loss_mask", "position_ids"]
+    @property
+    def required_keys(self) -> List[str]:
+        return ["sequence", "loss_mask"]

-    def __getitem__(self, index: int):
-        begin, end = self.store.sample_window(index)
-        x = self.store.fetch(begin, end, "sequence")
-        y = self.store.fetch(begin + 1, end + 1, "sequence")
-        position_ids = self.store.fetch(begin, end, "position_ids")
-        loss_mask = self.store.fetch(begin + 1, end + 1, "loss_mask")
-        return {
-            "input_ids": x.to(dtype=torch.long),
-            "target_ids": y.to(dtype=torch.long),
-            "position_ids": position_ids.to(dtype=torch.long),
-            "loss_mask": loss_mask.to(dtype=torch.bool),
-        }
+    def _fetch_data(self, begin_idx: int, end_idx: int, key: str) -> Tensor:
+        return self.storage.fetch(begin_idx, end_idx, key)
+
+    def __getitem__(self, index):
+        begin_idx, end_idx = self.get_index(index)
+
+        x = self._fetch_data(begin_idx, end_idx, "sequence").to(dtype=torch.long)
+        y = self._fetch_data(begin_idx + 1, end_idx + 1, "sequence").to(
+            dtype=torch.long
+        )
+        loss_mask = self._fetch_data(begin_idx + 1, end_idx + 1, "loss_mask").to(
+            dtype=torch.bool
+        )
+
+        return {"input_ids": x, "target_ids": y, "loss_mask": loss_mask}


@DatasetFactory.register("dpo")
 class DPODataset(BaseDataset):
-    """Record-structured dataset for Direct Preference Optimization.
+    """Dataset for Direct Preference Optimization training."""

-    Each sample is one preference pair (chosen + rejected) and is an
-    independent training unit — no windowing, stride, or cross-record
-    concatenation.  This keeps each sequence self-contained so attention
-    never leaks across preference pairs.
+    def __init__(self, window_size: int, stride: int):
+        super().__init__(window_size, stride)

-    Two loading paths (handled by :class:`DatasetFactory`):
+    @property
+    def required_keys(self) -> List[str]:
+        return ["chosen", "rejected", "chosen_mask", "rejected_mask"]

-    - **Pre-tokenized** (H5/bin): ``store.load(path)`` reads per-record
-      tensors; ``__getitem__`` returns them directly.
-    - **Raw JSONL** (``tokenizer_path=...``): builds a lazy processor
-      via :func:`dpo_processor` that tokenises on the fly — no packing,
-      no ``position_ids``.
-    """
+    def _fetch_data(self, begin_idx: int, end_idx: int, key: str) -> Tensor:
+        return self.storage.fetch(begin_idx, end_idx, key)

-    required_keys = ["chosen", "rejected", "chosen_mask", "rejected_mask"]
+    def __getitem__(self, index: int):
+        begin_idx, end_idx = self.get_index(index)

-    def make_processor(self, tokenizer, max_len: int):
-        return partial(dpo_processor, tokenizer=tokenizer, max_len=max_len)
+        chosen = self._fetch_data(begin_idx, end_idx, "chosen").to(dtype=torch.long)
+        rejected = self._fetch_data(begin_idx, end_idx, "rejected").to(dtype=torch.long)
+        chosen_mask = self._fetch_data(begin_idx, end_idx, "chosen_mask").to(
+            dtype=torch.bool
+        )
+        rejected_mask = self._fetch_data(begin_idx, end_idx, "rejected_mask").to(
+            dtype=torch.bool
+        )

-    def __getitem__(self, index: int) -> Dict[str, Tensor]:
        return {
-            "chosen": self.store.fetch_record(index, "chosen").to(dtype=torch.long),
-            "rejected": self.store.fetch_record(index, "rejected").to(dtype=torch.long),
-            "chosen_mask": self.store.fetch_record(index, "chosen_mask").to(
-                dtype=torch.bool
-            ),
-            "rejected_mask": self.store.fetch_record(index, "rejected_mask").to(
-                dtype=torch.bool
-            ),
+            "chosen": chosen,
+            "rejected": rejected,
+            "chosen_mask": chosen_mask,
+            "rejected_mask": rejected_mask,
        }


@DatasetFactory.register("grpo")
 class GRPODataset(BaseDataset):
-    """Dataset for offline Group Relative Policy Optimization.
+    """Dataset for Group Relative Policy Optimization training."""

-    Each sample is one prompt with its group of responses and scalar
-    rewards — an independent training unit with no windowing or stride.
+    def __init__(self, window_size: int, stride: int):
+        super().__init__(window_size, stride)

-    Expected storage layout (produced by JsonlStore or pre-tokenized):
+    @property
+    def required_keys(self) -> List[str]:
+        return ["prompts", "responses", "masks", "rewards"]

-    - ``prompts``:   List[Tensor]  — one 1-D token tensor per record
-    - ``responses``: List[List[Tensor]] — G response tensors per record
-    - ``masks``:     List[List[Tensor]] — G mask tensors per record
-    - ``rewards``:   List[Tensor]  — one 1-D float tensor (len G) per record
-    """
-
-    required_keys = ["prompts", "responses", "masks", "rewards"]
+    def _fetch_data(self, begin_idx: int, end_idx: int, key: str) -> Tensor:
+        return self.storage.fetch(begin_idx, end_idx, key)

    def __getitem__(self, index: int) -> Dict[str, Tensor]:
-        prompts = self.store.fetch_record(index, "prompts")
-        responses = self.store.fetch_record(index, "responses")
-        masks = self.store.fetch_record(index, "masks")
-        rewards = self.store.fetch_record(index, "rewards")
+        begin_idx, end_idx = self.get_index(index)
+
+        prompts = self._fetch_data(begin_idx, end_idx, "prompts")
+        responses = self._fetch_data(begin_idx, end_idx, "responses")
+        masks = self._fetch_data(begin_idx, end_idx, "masks")
+        rewards = self._fetch_data(begin_idx, end_idx, "rewards")
+
        return {
-            "prompts": prompts.to(dtype=torch.long),
-            "responses": [r.to(dtype=torch.long) for r in responses],
-            "masks": [m.to(dtype=torch.bool) for m in masks],
-            "rewards": rewards.to(dtype=torch.float32),
+            "prompts": prompts,
+            "responses": responses,
+            "masks": masks,
+            "rewards": rewards,
        }
@@ -5,15 +5,7 @@ import torch.distributed as dist
 from torch.utils.data import Dataset, Sampler


-class RDSampler(Sampler[int]):
-    """Resumable Distributed Sampler.
-
-    A distributed sampler that supports checkpoint-based resume: iteration
-    state (epoch, position) is tracked so training can continue from the
-    exact sample after a restart.  Shards the dataset across
-    ``dist.world_size`` replicas with optional shuffling.
-    """
-
+class ResumableDistributedSampler(Sampler[int]):
    def __init__(
        self,
        data_source: Dataset,
@@ -51,7 +43,6 @@ class RDSampler(Sampler[int]):
        offset = 0 if drop_last else self.num_replicas - 1
        self.num_samples_per_replica = (self.num_samples + offset) // self.num_replicas
        self.total_size = self.num_samples_per_replica * self.num_replicas
-        self.iter = self.iter % self.num_samples_per_replica

        self._indices = None

@@ -82,12 +73,6 @@ class RDSampler(Sampler[int]):

        self.epoch += 1
        self._indices = None
-        self.iter = self.iter % self.num_samples_per_replica
-
-    @property
-    def _remaining(self):
-        remaining = self.num_samples_per_replica - self.iter
-        return max(remaining, 0)

    def __len__(self):
-        return self._remaining
+        return self.num_samples_per_replica
@@ -1,71 +1,107 @@
 """Storage backends for different data formats.

-Architecture (composition over inheritance):
-
-    Store (ABC)               — owns _data/_cum/_offsets bookkeeping
-                                  + window_size/stride for sample-id
-                                  indexing.  __getitem__/__len__ produce
-                                  the smallest iterable unit so Dataset
-                                  classes are pure delegators.
-    Streamable (mixin)        — raw token slice  fetch(begin, end, keys)
-    Recordable (mixin)        — raw record slice fetch_record(idx, keys)
-
-    H5Store(Store, Streamable, Recordable)
-    MmapStore(Store, Streamable, Recordable)
-    JsonlStore(Store, Streamable, Recordable)
-
-Each mixin is a stateless trait that relies on ``self._data`` etc.
-provided by :class:`Store`.  Concrete stores mix in whichever access
-primitives they support — ``Store`` is the sole base class, so there is
-no diamond inheritance or MRO ambiguity.
-
-Sample-id indexing lives on :class:`Store`, not on the dataset:
-
- **Stream mode** (``window_size > 0``):  ``len(store)`` returns the number
-  of ``(window_size, stride)`` windows that fit in the token river;
-  ``store[i]`` returns the *i*-th window as a dict of per-key tensors;
-  ``store.sample_window(i)`` exposes the underlying ``(begin, end)``
-  token slice for callers (e.g. next-token trainers) that need a +1
-  shifted companion window.
- **Record mode** (``num_records > 0``):  ``len(store)`` returns the
-  record count; ``store[i]`` returns the *i*-th record dict.
-
-Raw token/record access via :meth:`fetch` / :meth:`fetch_record`
-remains available for low-level callers that want explicit index
-control.  ``store.token_count`` is the total stream token count (what
-``len(store)`` used to mean in the legacy stream-only API).
-
-``segments_are_records`` (class attribute on each Store subclass)
-tells ``_normalize`` whether segments are inherently per-record (H5/
-JSONL) or opaque shards (bin).  Record access for bin relies on
-``_offsets`` instead.
-
-:class:`JsonlStore` supports a lazy mode (``processor=fn``) that keeps
-raw records and defers tokenisation to ``fetch_record`` — used by DPO
-to train directly from a ``.jsonl`` file without a pre-tokenised copy.
+Each storage handles format-specific loading (HDF5, JSON, etc.) and provides
+a uniform interface for data access and length observation via fetchers.
 """

 import bisect
-import glob
 import json
-import logging
+import os
 from abc import ABC, abstractmethod
 from pathlib import Path
-from typing import Callable, Dict, List, Optional, Tuple, Union
+from typing import Callable, Dict, List, Optional, Union

+import h5py
 import torch
 from torch import Tensor

-from astrai.config.preprocess_config import PipelineConfig
 from astrai.factory import BaseFactory
-from astrai.preprocessing.transform import TokenizeTransform
-from astrai.serialization import (
-    load_bin,
-    load_bin_offsets,
-    load_h5,
-)

-logger = logging.getLogger(__name__)
+
+def save_h5(file_path: str, file_name: str, tensor_group: Dict[str, List[Tensor]]):
+    os.makedirs(file_path, exist_ok=True)
+    full_file_path = os.path.join(file_path, f"{file_name}.h5")
+    with h5py.File(full_file_path, "w") as f:
+        for key, tensors in tensor_group.items():
+            grp = f.create_group(key)
+            for idx, tensor in enumerate(tensors):
+                arr = tensor.cpu().numpy()
+                grp.create_dataset(f"data_{idx}", data=arr)
+
+
+def load_h5(file_path: str, share_memory=True) -> Dict[str, List[Tensor]]:
+    tensor_group: Dict[str, List[Tensor]] = {}
+
+    root_path = Path(file_path)
+    h5_files = list(root_path.rglob("*.h5")) + list(root_path.rglob("*.hdf5"))
+
+    for h5_file in h5_files:
+        with h5py.File(h5_file, "r") as f:
+            for key in f.keys():
+                grp = f[key]
+                dsets = []
+                for dset_name in grp.keys():
+                    dset = grp[dset_name]
+                    tensor = torch.from_numpy(dset[:])
+                    if share_memory:
+                        tensor = tensor.share_memory_()
+                    dsets.append(tensor)
+
+                if tensor_group.get(key) is None:
+                    tensor_group[key] = []
+                tensor_group[key].extend(dsets)
+
+    return tensor_group
+
+
+def save_json(file_path: str, file_name: str, tensor_group: Dict[str, List[Tensor]]):
+    os.makedirs(file_path, exist_ok=True)
+    full_file_path = os.path.join(file_path, f"{file_name}.json")
+    json_data = {}
+    for key, tensors in tensor_group.items():
+        json_data[key] = [tensor.tolist() for tensor in tensors]
+    with open(full_file_path, "w", encoding="utf-8") as f:
+        json.dump(json_data, f, ensure_ascii=False)
+
+
+def load_json(
+    file_path: str,
+    share_memory: bool = True,
+    tokenizer: Optional[Callable[[str], List[int]]] = None,
+) -> Dict[str, List[Tensor]]:
+    """Load tensor data from JSON files.
+
+    Supports two modes:
+    - Pre-tokenized: JSON values are List[List[int]] (token IDs), loaded as-is.
+    - Raw text: JSON values are List[str], tokenized via ``tokenizer`` callable
+      at load time. A ``tokenizer`` receives a str and returns List[int].
+
+    Non-data JSON files (e.g. config.json) with scalar/object values are
+    silently skipped.
+    """
+    tensor_group: Dict[str, List[Tensor]] = {}
+    root_path = Path(file_path)
+    json_files = list(root_path.rglob("*.json")) + list(root_path.rglob("*.jsonl"))
+    for json_file in json_files:
+        with open(json_file, "r", encoding="utf-8") as f:
+            data = json.load(f)
+        if not isinstance(data, dict):
+            continue
+        for key, sequences in data.items():
+            if not isinstance(sequences, list):
+                continue
+            tensors = []
+            for seq in sequences:
+                if tokenizer is not None and isinstance(seq, str):
+                    seq = tokenizer(seq)
+                tensor = torch.tensor(seq, dtype=torch.long)
+                if share_memory:
+                    tensor = tensor.share_memory_()
+                tensors.append(tensor)
+            if tensor_group.get(key) is None:
+                tensor_group[key] = []
+            tensor_group[key].extend(tensors)
+    return tensor_group


 def detect_format(load_path: str) -> str:
@@ -75,7 +111,7 @@ def detect_format(load_path: str) -> str:
        load_path: Directory or file path

    Returns:
-        Format string ("h5", "bin", "jsonl", or "processed")
+        Format string ("h5" or "json")

    Raises:
        FileNotFoundError: If no supported data files are found
@@ -85,580 +121,181 @@ def detect_format(load_path: str) -> str:
        suffix = root.suffix.lower()
        if suffix in (".h5", ".hdf5"):
            return "h5"
-        if suffix == ".jsonl":
-            return "jsonl"
+        if suffix in (".json", ".jsonl"):
+            return "json"
        raise ValueError(f"Unsupported file format: {suffix}")

-    h5_files = [
-        Path(p)
-        for pattern in ("*.h5", "*.hdf5")
-        for p in glob.glob(str(root / "**" / pattern), recursive=True)
-    ]
+    h5_files = list(root.rglob("*.h5")) + list(root.rglob("*.hdf5"))
    if h5_files:
        return "h5"
-    bin_files = [Path(p) for p in glob.glob(str(root / "**" / "*.bin"), recursive=True)]
-    if bin_files:
-        has_meta = (root / "meta.json").exists() or len(
-            [Path(p) for p in glob.glob(str(root / "**" / "meta.json"), recursive=True)]
-        ) > 0
-        if has_meta:
-            return "bin"
-    jsonl_files = [
-        Path(p) for p in glob.glob(str(root / "**" / "*.jsonl"), recursive=True)
-    ]
-    if jsonl_files:
-        return "jsonl"
+    json_files = list(root.rglob("*.json")) + list(root.rglob("*.jsonl"))
+    if json_files:
+        return "json"
    raise FileNotFoundError(f"No supported data files found at {load_path}")


-class Store(ABC):
-    """Common base for all storage backends.
+class BaseSegmentFetcher:
+    """Fetches data segments across multiple tensor segments.

-    A Store owns both its data layout AND its sample-id → token/record
-    index translation.  Datasets are thin wrappers that bind a Store
-    to a particular train-type's key mapping; they never know about
-    window/stride math.
-
-    Two iteration modes:
-
-    - **Stream** (``window_size > 0``): data is treated as one long
-      token river.  ``len(store)`` returns the number of windows;
-      ``store[i]`` slices every stream-compatible key to window ``i``;
-      ``store.sample_window(i)`` returns the ``(begin, end)`` token
-      slice for callers needing a +1 shifted companion window.
-    - **Record** (``num_records > 0``): data is per-record.
-      ``len(store)`` returns ``num_records``; ``store[i]`` returns
-      the *i*-th record as a dict.
-
-    Raw token slicing is still available via :meth:`fetch` (mixed in
-    by :class:`Streamable`) when a store has stream support configured.
-    Raw record slicing via :meth:`fetch_record` (mixed in by
-    :class:`Recordable`) when a store has record support.
-
-    ``token_count`` exposes the raw total stream length — this is what
-    ``len(store)`` returned in the legacy stream-only API and what
-    stream-bound ``fetch`` uses for its bounds check.
+    Maintains cumulative lengths for efficient range queries across
+    multiple discontinuous segments.
    """

-    segments_are_records: bool = False
+    def __init__(self, segments: List[Tensor]):
+        self.segments = segments
+        self.cum_lengths = []

-    def __init__(
-        self,
-        window_size: int = 0,
-        stride: Optional[int] = None,
-    ):
-        self._data: Dict[str, List[Tensor]] = {}
-        self._cum: Dict[str, List[int]] = {}
-        self._offsets: Dict[str, List[int]] = {}
-        self._length: int = 0
-        self._num_records: int = 0
-        self._window_size: int = int(window_size)
-        self._stride: int = int(stride) if stride is not None else int(window_size)
+        total = 0
+        for seg in segments:
+            total += torch.numel(seg)
+            self.cum_lengths.append(total)

-    @abstractmethod
-    def load(self, path: str, **kwargs) -> None:
-        raise NotImplementedError
-
-    @property
-    def keys(self) -> List[str]:
-        return list(self._data.keys())
-
-    @property
-    def window_size(self) -> int:
-        return self._window_size
-
-    @property
-    def stride(self) -> int:
-        return self._stride
-
-    @property
-    def token_count(self) -> int:
-        """Total tokens across all stream segments.
-
-        Useful for the bounds-checked raw :meth:`fetch` and as the
-        legacy ``len(store)`` value.
-        """
-        return self._length
-
-    @property
-    def num_records(self) -> int:
-        """Number of records available via :meth:`fetch_record`.
-
-        Non-zero only when the backing layout provides per-record
-        indexing (H5/JSONL segments or bin ``_offsets``).
-        """
-        return self._num_records
-
-    @property
-    def num_samples(self) -> int:
-        """Number of items produced by ``__getitem__``.
-
-        Stream-mode wins when ``window_size > 0`` and there are tokens
-        to slice; otherwise falls back to ``num_records``.
-        """
-        if self._window_size > 0 and self._length > 0:
-            total = self._length
-            w = self._window_size
-            if total <= w:
-                return 0
-            return (total - 1 - w) // self._stride + 1
-        return self._num_records
+        self.total_length = total

    def __len__(self) -> int:
-        return self.num_samples
+        return self.total_length

-    def __getitem__(self, index: int) -> Dict[str, Tensor]:
-        if index < 0:
-            index += self.num_samples
-        if not 0 <= index < self.num_samples:
-            raise IndexError(
-                f"Store index out of range: {index}, num_samples={self.num_samples}"
-            )
-        if self._window_size > 0 and self._length > 0:
-            begin, end = self.sample_window(index)
-            keys = self._stream_keys()
-            return {k: self.fetch(begin, end, k) for k in keys}
-        return self.fetch_record(index, self._record_keys())
+    def fetch_data(self, begin_idx: int, end_idx: int) -> Tensor:
+        """Fetch data in the range [begin_idx, end_idx)."""
+        if not (
+            0 <= begin_idx < self.total_length and 0 <= end_idx <= self.total_length
+        ):
+            raise ValueError("begin_idx or end_idx out of bounds")
+        if begin_idx >= end_idx:
+            return torch.tensor([], dtype=torch.long)

-    def sample_window(self, index: int) -> Tuple[int, int]:
-        """Return ``(begin, end)`` token positions for stream sample *index*.
+        seg_start_idx = bisect.bisect_right(self.cum_lengths, begin_idx)
+        seg_end_idx = bisect.bisect_left(self.cum_lengths, end_idx)

-        The clipped tail keeps the last reachable window inside the
-        token river instead of overshooting.  Caller is responsible
-        for staying within :attr:`num_samples`: an out-of-range index
-        raises ``IndexError``.
+        result_segments = []
+
+        for i in range(seg_start_idx, seg_end_idx + 1):
+            prev_cum = self.cum_lengths[i - 1] if i > 0 else 0
+            start = max(begin_idx - prev_cum, 0)
+            end = min(end_idx - prev_cum, len(self.segments[i]))
+            result_segments.append(self.segments[i][start:end])
+
+        return torch.cat(result_segments, dim=0)
+
+
+class MultiSegmentFetcher:
+    """Manages multiple segment fetchers for different data keys."""
+
+    def __init__(self, multi_segments: Dict):
+        self.multi_keys = list(multi_segments.keys())
+        self.multi_fetchers = {
+            key: BaseSegmentFetcher(segments)
+            for key, segments in multi_segments.items()
+        }
+
+    def __len__(self) -> int:
+        """Returns the minimum length across all fetchers."""
+        if not self.multi_fetchers:
+            return 0
+        len_list = [len(seg) for seg in self.multi_fetchers.values()]
+        return min(len_list)
+
+    def key_fetch(
+        self, begin_idx: int, end_idx: int, keys: Union[str, List[str]]
+    ) -> Dict:
+        """Fetch data for specific keys."""
+        fetch_dict = {}
+        keys = [keys] if isinstance(keys, str) else keys
+
+        for key in keys:
+            fetcher = self.multi_fetchers[key]
+            fetch_tensor = fetcher.fetch_data(begin_idx, end_idx)
+            fetch_dict[key] = fetch_tensor
+
+        return fetch_dict if len(keys) > 1 else fetch_dict[keys[0]]
+
+    def fetch_data(self, begin_idx: int, end_idx: int) -> Dict:
+        """Fetch all keys."""
+        return self.key_fetch(begin_idx, end_idx, self.multi_keys)
+
+
+class BaseStorage(ABC):
+    """Abstract storage backend for loading and dispatching data.
+
+    Storage encapsulates format-specific loading and provides a uniform
+    interface for data access and length observation. Subclasses handle
+    different data formats (HDF5, JSON, etc.) while exposing the same
+    fetch interface.
+    """
+
+    def __init__(self):
+        self._fetcher: Optional[MultiSegmentFetcher] = None
+
+    @abstractmethod
+    def load(self, load_path: str, tokenizer=None) -> None:
+        """Load data from the given path into internal fetcher."""
+        raise NotImplementedError
+
+    def __len__(self) -> int:
+        """Total number of raw elements (tokens) in storage."""
+        if self._fetcher is None:
+            return 0
+        return len(self._fetcher)
+
+    def fetch(self, begin_idx: int, end_idx: int, keys: Union[str, List[str]]):
+        """Fetch data for the given keys and index range.
+
+        Args:
+            begin_idx: Starting index (inclusive)
+            end_idx: Ending index (exclusive)
+            keys: Single key or list of keys to fetch
+
+        Returns:
+            Tensor if single key, Dict[str, Tensor] if multiple keys
        """
-        if self._window_size <= 0:
-            raise RuntimeError("sample_window() requires window_size > 0 (stream mode)")
-        if self._window_size <= 0 or self._length <= self._window_size:
-            raise IndexError(
-                f"Data too short for window: token_count={self._length}, "
-                f"window_size={self._window_size}"
-            )
-        if not 0 <= index < self.num_samples:
-            raise IndexError(
-                f"Sample index out of range: {index}, num_samples={self.num_samples}"
-            )
-        total = self._length
-        begin = min(index * self._stride, total - 1 - self._window_size)
-        end = min(begin + self._window_size, total - 1)
-        return begin, end
-
-    def _stream_keys(self) -> List[str]:
-        out: List[str] = []
-        for k, tensors in self._data.items():
-            if tensors and isinstance(tensors[0], list):
-                continue
-            out.append(k)
-        return out
-
-    def _record_keys(self) -> List[str]:
-        return list(self._data.keys())
-
-    def _normalize(
-        self,
-        raw: Dict[str, list],
-        offsets: Optional[Dict[str, List[int]]] = None,
-    ):
-        """Register segments and pre-compute indices for both access modes.
-
-        Stream mode: ``_cum[key]`` accumulates per-segment lengths so
-        ``Streamable._fetch_stream_key`` can bisect across segments
-        without concatenation.
-
-        Record mode: if *offsets* is provided (bin layout),
-        ``_offsets[key]`` stores cumulative per-record offsets into the
-        single concatenated segment.  Otherwise, when
-        ``segments_are_records`` is True (H5/JSONL), ``_data[key]`` is
-        a per-record list and ``fetch_record`` indexes it directly.
-
-        Nested keys (GRPO ``responses``/``masks`` as
-        ``List[List[Tensor]]``) are stored as-is and excluded from both
-        cumulative bookkeepings — they are only accessed record-by-record.
-        """
-        flat_lengths = []
-        for key, tensors in raw.items():
-            self._data[key] = tensors
-            if not tensors:
-                self._cum[key] = []
-                flat_lengths.append(0)
-                continue
-            if isinstance(tensors[0], list):
-                self._cum[key] = []
-                continue
-            cum = []
-            total = 0
-            for t in tensors:
-                total += t.shape[0]
-                cum.append(total)
-            self._cum[key] = cum
-            flat_lengths.append(cum[-1] if cum else 0)
-        self._length = min(flat_lengths) if flat_lengths else 0
-
-        valid_offsets: Dict[str, List[int]] = {}
-        if offsets:
-            for key, off in offsets.items():
-                segs = self._data.get(key, [])
-                if len(segs) == 1 and len(off) > 1:
-                    valid_offsets[key] = off
-                elif len(segs) > 1:
-                    logger.warning(
-                        "Key '%s' has %d segments with offsets — record mode "
-                        "disabled for this key (multi-shard bin+offsets not "
-                        "supported). Merge shards or use H5/JSONL.",
-                        key,
-                        len(segs),
-                    )
-        self._offsets = valid_offsets
-        if valid_offsets:
-            record_counts = [len(v) - 1 for v in valid_offsets.values()]
-            self._num_records = min(record_counts) if record_counts else 0
-        elif self.segments_are_records:
-            per_record_counts = []
-            for key, tensors in self._data.items():
-                if tensors and isinstance(tensors[0], list):
-                    continue
-                per_record_counts.append(len(tensors))
-            self._num_records = min(per_record_counts) if per_record_counts else 0
-        else:
-            self._num_records = 0
-
-
-class Streamable:
-    """Mixin granting raw token-stream access via :meth:`fetch`.
-
-    Stateless trait relying on ``self._data``, ``self._cum``,
-    ``self._length`` maintained by :class:`Store`.  Stream mode is
-    active when the owning store has ``window_size > 0``; for stores
-    that can also serve record access (H5/JSONL/bin+offsets), the
-    ``fetch_record`` API from :class:`Recordable` is used instead.
-    """
-
-    def fetch(
-        self,
-        begin: int,
-        end: int,
-        keys: Union[str, List[str]],
-    ):
-        return _stream_fetch(self, begin, end, keys)
-
-
-def _stream_fetch(self, begin: int, end: int, keys: Union[str, List[str]]):
-    if not getattr(self, "_data", None):
-        raise RuntimeError("Store not loaded")
-    if not (0 <= begin < self._length and 0 <= end <= self._length):
-        raise ValueError(
-            f"Index out of bounds: begin={begin}, end={end}, length={self._length}"
-        )
-    if isinstance(keys, str):
-        return _fetch_stream_key(self, keys, begin, end)
-    return {k: _fetch_stream_key(self, k, begin, end) for k in keys}
-
-
-def _fetch_stream_key(self, key: str, begin: int, end: int) -> Tensor:
-    segments = self._data[key]
-    cum = self._cum[key]
-    seg_start = bisect.bisect_right(cum, begin)
-    seg_end = bisect.bisect_left(cum, end)
-
-    results = []
-    for i in range(seg_start, seg_end + 1):
-        prev = cum[i - 1] if i > 0 else 0
-        s = max(begin - prev, 0)
-        e = min(end - prev, segments[i].shape[0])
-        results.append(segments[i][s:e])
-
-    return results[0] if len(results) == 1 else torch.cat(results, dim=0)
-
-
-class Recordable:
-    """Mixin granting raw record access via :meth:`fetch_record`.
-
-    Stateless trait relying on ``self._data``, ``self._offsets``,
-    ``self._num_records`` maintained by :class:`Store`.
-    """
-
-    def fetch_record(
-        self,
-        index: int,
-        keys: Union[str, List[str]],
-    ):
-        return _record_fetch(self, index, keys)
-
-
-def _record_fetch(self, index: int, keys: Union[str, List[str]]):
-    if not getattr(self, "_data", None) and self._num_records == 0:
-        raise RuntimeError("Store not loaded")
-    if not 0 <= index < self._num_records:
-        raise ValueError(
-            f"Record index out of bounds: {index}, num_records={self._num_records}"
-        )
-    if isinstance(keys, str):
-        return _fetch_record_key(self, keys, index)
-    return {k: _fetch_record_key(self, k, index) for k in keys}
-
-
-def _fetch_record_key(self, key: str, index: int):
-    offsets = self._offsets.get(key)
-    if offsets:
-        start = offsets[index]
-        end = (
-            offsets[index + 1]
-            if index + 1 < len(offsets)
-            else self._data[key][0].shape[0]
-        )
-        return self._data[key][0][start:end]
-    return self._data[key][index]
-
-
-class StoreFactory(BaseFactory["Store"]):
-    """Factory for creating Store instances by type name."""
-
-
-@StoreFactory.register("h5")
-class H5Store(Store, Streamable, Recordable):
-    """HDF5-based storage backend (pre-tokenized data).
-
-    Each key is stored as a group of per-record datasets (``data_0``,
-    ``data_1``, …).  Supports both access modes:
-
-    - **Stream**: ``fetch(begin, end, key)`` and ``store[i]`` slice
-      across concatenated records via ``_cum`` — used by SEQ/SFT.
-    - **Record**: ``fetch_record(i, key)`` and ``store[i]`` (when
-      ``window_size == 0``) index ``_data[key]`` directly — used by
-      DPO/GRPO.
-    """
-
-    segments_are_records = True
-
-    def __init__(
-        self,
-        window_size: int = 0,
-        stride: Optional[int] = None,
-    ):
-        super().__init__(window_size=window_size, stride=stride)
-
-    def load(self, path: str, **kwargs):
-        self._normalize(load_h5(path))
-
-
-@StoreFactory.register("bin")
-class MmapStore(Store, Streamable, Recordable):
-    """Memory-mapped binary storage backend.
-
-    Each key is a single .bin file backed by ``np.memmap(mode="r")``.
-    No per-process memory duplication — all DataLoader workers share the
-    same OS page-cache pages.
-
-    Supports both access modes:
-
-    - **Stream**: always available via :meth:`fetch`.
-    - **Record** (``fetch_record(i, key)``): only when ``meta.json``
-      contains per-record ``offsets`` (written via
-      ``save_bin(..., record_keys=...)``).  Legacy bin files without
-      offsets have ``num_records == 0`` and ``len(store)`` reflects the
-      windowed sample count when ``window_size > 0``.
-
-    ``segments_are_records`` is ``False`` here (bin segments are
-    contiguous streams, not per-record) — record access is driven
-    purely by ``_offsets``.
-    """
-
-    segments_are_records = False
-
-    def __init__(
-        self,
-        window_size: int = 0,
-        stride: Optional[int] = None,
-    ):
-        super().__init__(window_size=window_size, stride=stride)
-        self._mmap_refs: List[Tensor] = []
-
-    def load(self, path: str, **kwargs):
-        self._mmap_refs = []
-        root = Path(path)
-        all_raw: Dict[str, List[Tensor]] = {}
-        all_offsets: Dict[str, List[int]] = {}
-        meta_paths = [
-            Path(p) for p in glob.glob(str(root / "**" / "meta.json"), recursive=True)
-        ]
-        for meta_path in meta_paths:
-            raw = load_bin(str(meta_path.parent))
-            off = load_bin_offsets(str(meta_path.parent))
-            for key, tensors in raw.items():
-                if key not in all_raw:
-                    all_raw[key] = []
-                all_raw[key].extend(tensors)
-            for key, o in off.items():
-                if key not in all_offsets:
-                    all_offsets[key] = []
-                all_offsets[key].extend(o)
-        if not meta_paths:
-            raise FileNotFoundError(f"No meta.json found under {path}")
-        self._normalize(all_raw, offsets=all_offsets or None)
-        for tensors in self._data.values():
-            self._mmap_refs.extend(tensors)
-
-
-class JsonlSource:
-    """Read raw JSON records from a ``.jsonl`` file or directory.
-
-    A thin reader used by :class:`JsonlStore` in processor mode — holds
-    no tokenizer, performs no tokenisation, just yields dicts.
-    """
-
-    def __init__(self, path: str):
-        self.path = Path(path)
-        self._records: Optional[List[dict]] = None
-
-    def load(self) -> List[dict]:
-        if self._records is None:
-            self._records = self._read(self.path)
-        return self._records
-
-    @staticmethod
-    def _read(root: Path) -> List[dict]:
-        if root.is_file():
-            return JsonlSource._read_file(root)
-        return JsonlSource._read_dir(root)
-
-    @staticmethod
-    def _read_file(path: Path) -> List[dict]:
-        records: List[dict] = []
-        with open(path, "r", encoding="utf-8") as f:
-            for line in f:
-                line = line.strip()
-                if not line:
-                    continue
-                try:
-                    records.append(json.loads(line))
-                except json.JSONDecodeError:
-                    logger.warning("Failed to parse JSON line in %s, skipping", path)
-        return records
-
-    @staticmethod
-    def _read_dir(root: Path) -> List[dict]:
-        records: List[dict] = []
-        for jsonl_path in sorted(root.glob("*.jsonl")):
-            records.extend(JsonlSource._read_file(jsonl_path))
-        return records
-
-
-@StoreFactory.register("jsonl")
-class JsonlStore(Store, Streamable, Recordable):
-    """JSONL reader with eager/lazy tokenisation modes.
-
-    A JSONL dataset is a ``.jsonl`` file or a directory of ``*.jsonl``
-    files plus (optionally) a ``dataset_config.json`` describing the
-    tokenization pipeline.
-
-    Three ways to supply an eager transform (first match wins):
-
-    - **Explicit** (``transform=``): caller-built
-      :class:`TokenizeTransform` applied eagerly.
-    - **Config file**: ``dataset_config.json`` alongside the ``*.jsonl``
-      files — loaded via :meth:`TokenizeTransform.from_config_file`.
-    - **Default messages** (``tokenizer_path=`` given, no config file):
-      a built-in chatml config that tokenises the ``messages`` field,
-      masking every role except ``assistant`` (loss on assistant only).
-      Lets SFT/SEQ train straight from a chat-style JSONL directory
-      without a hand-written config.
-
-    Two tokenisation modes, selected at :meth:`load` time:
-
-    - **Eager** (default): applies the transform to every record at load
-      time and registers per-key tensors via ``_normalize``.  Both
-      ``fetch`` (stream) and ``fetch_record`` (record) work.
-    - **Lazy** (``processor=fn`` passed): keeps raw records and defers
-      tokenisation to ``fetch_record``.  Only record access works —
-      ``len(store)`` returns ``num_records``; stream primitives raise.
-    """
-
-    CONFIG_NAME = "dataset_config.json"
-    segments_are_records = True
-
-    _DEFAULT_MESSAGES_CONFIG = {
-        "version": 1,
-        "input": {
-            "sections": [{"field": "messages", "action": "$role", "template": True}]
-        },
-        "mask": {"system": "mask", "user": "mask", "assistant": "train"},
-        "mask_default": "mask",
-        "output": {"position_ids_mode": "doc_reset"},
-    }
-
-    def __init__(
-        self,
-        window_size: int = 0,
-        stride: Optional[int] = None,
-    ):
-        super().__init__(window_size=window_size, stride=stride)
-        self._source: Optional[JsonlSource] = None
-        self._processor: Optional[Callable[[dict], Dict[str, Tensor]]] = None
-        self._keys_cache: Optional[List[str]] = None
-
-    def load(self, path: str, transform=None, processor=None, **kwargs):
-        self._source = JsonlSource(path)
-        records = self._source.load()
-
-        if processor is not None:
-            self._processor = processor
-            self._num_records = len(records)
-            return
-
-        if transform is None:
-            root = Path(path)
-            config_path = root / self.CONFIG_NAME if root.is_dir() else None
-            if config_path is not None and config_path.exists():
-                transform = TokenizeTransform.from_config_file(str(config_path))
-            else:
-                tokenizer_path = kwargs.get("tokenizer_path")
-                if not tokenizer_path:
-                    raise FileNotFoundError(
-                        f"JSONL dataset config not found. Expected "
-                        f"{self.CONFIG_NAME} alongside *.jsonl files, pass an "
-                        f"explicit transform, pass processor= for lazy "
-                        f"on-the-fly tokenisation, or pass tokenizer_path= to "
-                        f"use the built-in messages config."
-                    )
-                config = PipelineConfig.from_dict(self._DEFAULT_MESSAGES_CONFIG)
-                transform = TokenizeTransform(config, tokenizer_path)
-
-        transformed = transform.apply(records)
-        self._normalize(transformed)
+        if self._fetcher is None:
+            raise RuntimeError("Storage not loaded")
+        return self._fetcher.key_fetch(begin_idx, end_idx, keys)

    @property
    def keys(self) -> List[str]:
-        if self._processor is not None:
-            if self._keys_cache is None and self._num_records > 0:
-                sample = self._processor(self._source.load()[0])
-                self._keys_cache = list(sample.keys())
-            return self._keys_cache or []
-        return list(self._data.keys())
+        """Return the data keys available in this storage."""
+        if self._fetcher is None:
+            return []
+        return self._fetcher.multi_keys

-    def fetch_record(self, index: int, keys: Union[str, List[str]]):
-        if self._processor is not None:
-            if not 0 <= index < self._num_records:
-                raise ValueError(
-                    f"Record index out of bounds: {index}, "
-                    f"num_records={self._num_records}"
-                )
-            record = self._source.load()[index]
-            data = self._processor(record)
-            if isinstance(keys, str):
-                return data[keys]
-            return {k: data[k] for k in keys}
-        return _record_fetch(self, index, keys)

-    def fetch(self, begin: int, end: int, keys: Union[str, List[str]]):
-        if self._processor is not None:
-            raise RuntimeError(
-                "JsonlStore in lazy (processor) mode does not support "
-                "stream fetch(); use fetch_record() instead."
-            )
-        return _stream_fetch(self, begin, end, keys)
+class StorageFactory(BaseFactory["BaseStorage"]):
+    """Factory for creating storage backends by type name.

-    def __getitem__(self, index: int) -> Dict[str, Tensor]:
-        if self._processor is not None:
-            return self.fetch_record(index, self._record_keys())
-        return super().__getitem__(index)
+    Example:
+        @StorageFactory.register("custom")
+        class CustomStorage(BaseStorage):
+            ...
+
+        storage = StorageFactory.create("custom")
+    """
+
+    @classmethod
+    def _validate_component(cls, storage_cls: type) -> None:
+        if not issubclass(storage_cls, BaseStorage):
+            raise TypeError(f"{storage_cls.__name__} must inherit from BaseStorage")
+
+
+@StorageFactory.register("h5")
+class H5Storage(BaseStorage):
+    """HDF5-based storage backend (pre-tokenized data)."""
+
+    def load(self, load_path: str, tokenizer=None) -> None:
+        segments = load_h5(load_path)
+        self._fetcher = MultiSegmentFetcher(segments)
+
+
+@StorageFactory.register("json")
+class JSONStorage(BaseStorage):
+    """JSON-based storage backend.
+
+    Supports two modes:
+    - Pre-tokenized: JSON values are List[List[int]], loaded as-is.
+    - Raw text: JSON values are List[str], tokenized via ``tokenizer``
+      callable (str -> List[int]) at load time.
+    """
+
+    def load(self, load_path: str, tokenizer=None) -> None:
+        segments = load_json(load_path, tokenizer=tokenizer)
+        self._fetcher = MultiSegmentFetcher(segments)
@@ -1,30 +0,0 @@
-"""CUDA attention kernel wrappers with torch fallback.
-
-Public API:
-    - ``attn_decode`` — single-query decode attention
-    - ``attn_prefill`` — multi-query prefill attention
-    - ``attn_paged_decode`` — paged decode attention (direct page-table access)
-
-Interface (shared by all wrappers):
-    causal_offset: -1 = non-causal; >=0 = absolute position of first Q token
-    mask:       2D [batch, kv_len] or 3D [batch, q_len, kv_len] (bool, True = keep)
-    scale:      0.0 = auto (1/sqrt(head_dim)); >0 = explicit
-    layout:     "bhld" (default) or "blhd"
-
-Causal and mask can coexist — both are applied simultaneously.
-
-Each wrapper dispatches to its compiled CUDA kernel (``astrai.extension.attn_*``)
-when available, otherwise falls back to ``torch.nn.functional.scaled_dot_product_attention``.
-"""
-
-from astrai.extension.loader import KERNEL_NAMES, is_available
-from astrai.extension.ops import attention, attn_decode, attn_paged_decode, attn_prefill
-
-__all__ = [
-    "attn_decode",
-    "attn_paged_decode",
-    "attn_prefill",
-    "attention",
-    "is_available",
-    "KERNEL_NAMES",
-]
@@ -1,36 +0,0 @@
-"""Dynamic discovery and loading of compiled CUDA kernel modules.
-
-Each kernel is registered in ``csrc/build.py`` and built into a ``.so`` placed
-in this package directory. On import we try to load each one; kernels that
-failed to build (or are running on a CPU-only machine) are marked unavailable
-so the wrapper functions can fall back to ``torch`` SDPA.
-"""
-
-import importlib
-import logging
-
-logger = logging.getLogger(__name__)
-
-KERNEL_NAMES = ["attn_decode", "attn_prefill", "attn_paged_decode"]
-
-_available: dict[str, bool] = {}
-_modules: dict[str, object] = {}
-
-for _name in KERNEL_NAMES:
-    try:
-        _mod = importlib.import_module(f".{_name}", package=__package__)
-        _available[_name] = True
-        _modules[_name] = _mod
-    except ImportError:
-        _available[_name] = False
-        _modules[_name] = None
-
-
-def is_available(name: str) -> bool:
-    """Return ``True`` if the compiled kernel ``name`` was loaded."""
-    return _available.get(name, False)
-
-
-def get_module(name: str) -> object:
-    """Return the loaded kernel module for ``name``, or ``None`` if unavailable."""
-    return _modules.get(name)
@@ -1,298 +0,0 @@
-"""GQA attention wrapper functions — one entry point per compiled kernel.
-
-Each wrapper dispatches to its CUDA kernel (loaded in ``loader.py``) when
-available, otherwise falls back to ``torch`` SDPA.
-
-Interface (all functions):
-    causal_offset: -1 = non-causal; >=0 = absolute position of first Q token
-    mask:       2D [batch, kv_len] or 3D [batch, q_len, kv_len] (bool)
-    scale:      0.0 = auto (1/sqrt(head_dim)); >0 = explicit
-    layout:     "bhld" (default) or "blhd"
-
-Add new kernel wrappers here; split into per-variant files only if this file
-grows large.
-"""
-
-import math
-
-import torch
-import torch.nn.functional as F
-
-from astrai.extension.loader import _available, _modules
-
-_LAYOUT_CODES: dict[str, int] = {"bhld": 0, "blhd": 1}
-
-
-def _parse_layout(layout: str | int) -> int:
-    if isinstance(layout, int):
-        return layout
-    code = _LAYOUT_CODES.get(layout.lower())
-    if code is None:
-        raise ValueError(
-            f"unknown layout '{layout}', expected one of {list(_LAYOUT_CODES)}"
-        )
-    return code
-
-
-def _to_bhld(t: torch.Tensor, layout: int) -> torch.Tensor:
-    """Normalize to b h l d view. Zero-copy transpose if layout==1 (b l h d)."""
-    if layout == 1:
-        return t.transpose(1, 2)
-    return t
-
-
-def _expand_kv_heads(
-    k: torch.Tensor, v: torch.Tensor, q_head: int
-) -> tuple[torch.Tensor, torch.Tensor]:
-    """Expand K/V heads to match Q heads for GQA fallback."""
-    kv_head = k.size(1)
-    if kv_head == q_head:
-        return k, v
-    group = q_head // kv_head
-    k = k.repeat_interleave(group, dim=1)
-    v = v.repeat_interleave(group, dim=1)
-    return k, v
-
-
-def _build_attn_mask(
-    q: torch.Tensor,
-    k: torch.Tensor,
-    mask: torch.Tensor | None,
-    causal_offset: int,
-    scale: float,
-) -> tuple[torch.Tensor | None, float]:
-    """Build SDPA-compatible attn_mask + resolved scale.
-
-    q and k must already be in b h l d layout.
-    Causal and mask can coexist: causal sets -inf above the diagonal, mask
-    sets -inf for padded positions. Both are OR'd into a single bool mask.
-    """
-    q_len = q.size(2)
-    kv_len = k.size(2)
-    head_dim = q.size(3)
-    resolved_scale = scale if scale and scale > 0 else 1.0 / math.sqrt(head_dim)
-
-    attn_mask = None
-
-    if mask is not None:
-        if mask.dim() == 2:
-            # [batch, kv_len] → [batch, 1, 1, kv_len]
-            attn_mask = mask[:, None, None, :]
-        elif mask.dim() == 3:
-            # [batch, q_len, kv_len] → [batch, 1, q_len, kv_len]
-            attn_mask = mask[:, None, :, :]
-        else:
-            raise ValueError(f"mask must be 2D or 3D, got {mask.dim()}D")
-
-    if causal_offset >= 0:
-        batch = q.size(0)
-        # q row i attends to kv cols 0..(causal_offset + i)
-        q_idx = torch.arange(q_len, device=q.device).unsqueeze(1)  # [q_len, 1]
-        kv_idx = torch.arange(kv_len, device=q.device).unsqueeze(0)  # [1, kv_len]
-        causal_bool = kv_idx > (causal_offset + q_idx)  # True = masked out
-        causal_mask = causal_bool.unsqueeze(0).expand(
-            batch, -1, -1
-        )  # [batch, q_len, kv_len]
-        causal_mask = causal_mask[:, None, :, :]  # [batch, 1, q_len, kv_len]
-
-        if attn_mask is not None:
-            attn_mask = attn_mask | causal_mask
-        else:
-            attn_mask = causal_mask
-
-    return attn_mask, resolved_scale
-
-
-def _torch_fallback(
-    q: torch.Tensor,
-    k: torch.Tensor,
-    v: torch.Tensor,
-    mask: torch.Tensor | None,
-    causal_offset: int,
-    scale: float,
-    q_layout: int,
-    kv_layout: int | None = None,
-) -> torch.Tensor:
-    """Reference attention via ``scaled_dot_product_attention``.
-
-    q_layout / kv_layout: 0 = b h l d, 1 = b l h d.
-    If kv_layout is None, uses q_layout (Q and K/V share the same layout).
-    """
-    if kv_layout is None:
-        kv_layout = q_layout
-    q = _to_bhld(q, q_layout)
-    k = _to_bhld(k, kv_layout)
-    v = _to_bhld(v, kv_layout)
-    k, v = _expand_kv_heads(k, v, q.size(1))
-    attn_mask, resolved_scale = _build_attn_mask(q, k, mask, causal_offset, scale)
-    out = F.scaled_dot_product_attention(
-        q, k, v, attn_mask=attn_mask, is_causal=False, scale=resolved_scale
-    )
-    # Restore Q's original layout
-    if q_layout == 1:
-        out = out.transpose(1, 2)
-    return out
-
-
-def _gather_kv_from_pages(
-    page_table: torch.Tensor,
-    k_cache: torch.Tensor,
-    v_cache: torch.Tensor,
-    page_size: int,
-    kv_len: int,
-) -> tuple[torch.Tensor, torch.Tensor]:
-    """Gather contiguous K/V from paged cache for torch SDPA fallback.
-
-    Shapes:
-        page_table : [batch, max_pages] (int64)
-        k_cache    : [n_pages, page_size, n_kv_heads, head_dim]
-        v_cache    : same as k_cache
-    Returns:
-        k, v : [batch, kv_len, n_kv_heads, head_dim]  (b l h d)
-    """
-    batch, max_pages = page_table.shape
-    _, ps, n_kv_heads, head_dim = k_cache.shape
-    if ps != page_size:
-        raise ValueError(f"k_cache page_size mismatch: {ps} vs {page_size}")
-
-    # Vectorized gather: build physical page + offset indices, then advanced-index
-    positions = torch.arange(kv_len, device=page_table.device)
-    logical_pages = positions // page_size  # [kv_len]
-    page_offsets = positions % page_size  # [kv_len]
-
-    phys_pages = page_table[:, logical_pages]  # [batch, kv_len]
-    # k_cache[phys_pages, page_offsets] → [batch, kv_len, n_kv_heads, head_dim] (b l h d)
-    k = k_cache[phys_pages, page_offsets]
-    v = v_cache[phys_pages, page_offsets]
-    return k, v
-
-
-def attn_decode(
-    q: torch.Tensor,
-    k: torch.Tensor,
-    v: torch.Tensor,
-    mask: torch.Tensor | None = None,
-    causal_offset: int = -1,
-    scale: float = 0.0,
-    layout: str = "bhld",
-) -> torch.Tensor:
-    li = _parse_layout(layout)
-    if _available["attn_decode"]:
-        return _modules["attn_decode"].attn_decode(
-            q,
-            k,
-            v,
-            mask=mask,
-            causal_offset=causal_offset,
-            scale=scale,
-            layout=li,
-        )
-    return _torch_fallback(q, k, v, mask, causal_offset, scale, q_layout=li)
-
-
-def attn_prefill(
-    q: torch.Tensor,
-    k: torch.Tensor,
-    v: torch.Tensor,
-    mask: torch.Tensor | None = None,
-    causal_offset: int = -1,
-    scale: float = 0.0,
-    layout: str = "bhld",
-) -> torch.Tensor:
-    li = _parse_layout(layout)
-    if _available["attn_prefill"]:
-        return _modules["attn_prefill"].attn_prefill(
-            q,
-            k,
-            v,
-            mask=mask,
-            causal_offset=causal_offset,
-            scale=scale,
-            layout=li,
-        )
-    return _torch_fallback(q, k, v, mask, causal_offset, scale, q_layout=li)
-
-
-def attn_paged_decode(
-    q: torch.Tensor,
-    page_table: torch.Tensor,
-    k_cache: torch.Tensor,
-    v_cache: torch.Tensor,
-    page_size: int,
-    kv_len: int,
-    mask: torch.Tensor | None = None,
-    causal_offset: int = -1,
-    scale: float = 0.0,
-    layout: str = "bhld",
-) -> torch.Tensor:
-    li = _parse_layout(layout)
-    if _available["attn_paged_decode"]:
-        return _modules["attn_paged_decode"].attn_paged_decode(
-            q,
-            page_table,
-            k_cache,
-            v_cache,
-            page_size,
-            kv_len,
-            mask=mask,
-            causal_offset=causal_offset,
-            scale=scale,
-            layout=li,
-        )
-    # Gathered K/V are always b l h d
-    k, v = _gather_kv_from_pages(page_table, k_cache, v_cache, page_size, kv_len)
-    return _torch_fallback(
-        q, k, v, mask, causal_offset, scale, q_layout=li, kv_layout=1
-    )
-
-
-def attention(
-    q: torch.Tensor,
-    k: torch.Tensor,
-    v: torch.Tensor,
-    mask: torch.Tensor | None = None,
-    causal_offset: int = -1,
-    scale: float = 0.0,
-    layout: str = "bhld",
-) -> torch.Tensor:
-    """Dispatch to decode or prefill attention based on the query length.
-
-    A query length of one is the decode case; longer queries use prefill.
-    The paged-cache decode path cannot be selected here because its page-table
-    arguments are not part of this interface.
-    """
-    li = _parse_layout(layout)
-
-    if q.ndim not in (2, 3, 4) or k.ndim != q.ndim or v.ndim != q.ndim:
-        raise ValueError(
-            "q, k, and v must all have the same rank in {2, 3, 4}, "
-            f"got {q.ndim}D, {k.ndim}D, {v.ndim}D"
-        )
-    if k.shape != v.shape:
-        raise ValueError(
-            f"k and v must have the same shape, got {k.shape} and {v.shape}"
-        )
-
-    original_ndim = q.ndim
-    if original_ndim == 2:
-        # [L, D] -> [1, 1, L, D] or [1, L, 1, D]
-        q = q.unsqueeze(0).unsqueeze(1 if li == 0 else 2)
-        k = k.unsqueeze(0).unsqueeze(1 if li == 0 else 2)
-        v = v.unsqueeze(0).unsqueeze(1 if li == 0 else 2)
-    elif original_ndim == 3:
-        # [B, L, D] -> single-head 4D input.
-        q = q.unsqueeze(1 if li == 0 else 2)
-        k = k.unsqueeze(1 if li == 0 else 2)
-        v = v.unsqueeze(1 if li == 0 else 2)
-
-    q_len = q.size(2 if li == 0 else 1)
-    if q_len == 1:
-        out = attn_decode(q, k, v, mask, causal_offset, scale, layout)
-    else:
-        out = attn_prefill(q, k, v, mask, causal_offset, scale, layout)
-
-    if original_ndim == 2:
-        return out.squeeze(0).squeeze(0 if li == 0 else 1)
-    if original_ndim == 3:
-        return out.squeeze(1 if li == 0 else 2)
-    return out
@@ -1,106 +1,149 @@
-"""Base factory with decorator-based registration and kwarg-filtered instantiation."""
+"""Base factory class for extensible component registration."""

 import inspect
-import sys
 from abc import ABC
-from typing import (
-    Callable,
-    Dict,
-    ForwardRef,
-    Generic,
-    List,
-    Optional,
-    Type,
-    TypeVar,
-    Union,
-)
-from typing import get_args as _get_args
-from typing import get_origin as _get_origin
+from typing import Callable, Dict, Generic, List, Optional, Tuple, Type, TypeVar

 T = TypeVar("T")


-def _resolve_type(
-    arg: Union[Type, str, ForwardRef], factory_cls: type
-) -> Optional[Type]:
-    """Resolve a generic type-arg (str forward-ref, ForwardRef, or class)."""
-    if not isinstance(arg, (str, ForwardRef)):
-        return arg
+class Registry:
+    """Flexible registry for component classes with category and priority support.

-    name = arg if isinstance(arg, str) else arg.__forward_arg__
-    if name == factory_cls.__name__:
-        return factory_cls
+    This registry stores component classes with optional metadata (category, priority).
+    It provides methods for registration, retrieval, and listing with filtering.
+    """

-    mod = sys.modules.get(factory_cls.__module__)
-    if mod is None:
-        return None
-    ns = vars(mod)
+    def __init__(self):
+        self._entries = {}  # name -> (component_cls, category, priority)

-    if isinstance(arg, ForwardRef):
-        return arg._evaluate(ns, None, recursive_guard=frozenset())
+    def register(
+        self,
+        name: str,
+        component_cls: Type,
+        category: Optional[str] = None,
+        priority: int = 0,
+    ) -> None:
+        """Register a component class with optional category and priority."""
+        if name in self._entries:
+            raise ValueError(f"Component '{name}' is already registered")
+        self._entries[name] = (component_cls, category, priority)

-    return ns.get(name)
+    def get(self, name: str) -> Type:
+        """Get component class by name."""
+        if name not in self._entries:
+            raise KeyError(f"Component '{name}' not found in registry")
+        return self._entries[name][0]
+
+    def get_with_metadata(self, name: str) -> Tuple[Type, Optional[str], int]:
+        """Get component class with its metadata."""
+        entry = self._entries.get(name)
+        if entry is None:
+            raise KeyError(f"Component '{name}' not found in registry")
+        return entry
+
+    def contains(self, name: str) -> bool:
+        """Check if a name is registered."""
+        return name in self._entries
+
+    def list_names(self) -> List[str]:
+        """Return list of registered component names."""
+        return sorted(self._entries.keys())
+
+    def list_by_category(self, category: str) -> List[str]:
+        """Return names of components belonging to a specific category."""
+        return sorted(
+            name for name, (_, cat, _) in self._entries.items() if cat == category
+        )
+
+    def list_by_priority(self, reverse: bool = False) -> List[str]:
+        """Return names sorted by priority (default ascending)."""
+        return sorted(
+            self._entries.keys(),
+            key=lambda name: self._entries[name][2],
+            reverse=reverse,
+        )
+
+    def entries(self) -> Dict[str, Tuple[Type, Optional[str], int]]:
+        """Return raw entries dictionary."""
+        return self._entries.copy()


 class BaseFactory(ABC, Generic[T]):
-    """Generic factory with decorator-based component registration.
+    """Generic factory class for component registration and creation.

-        class MyFactory(BaseFactory[MyBase]):
+    This base class provides a decorator-based registration pattern
+    for creating extensible component factories.
+
+    Example usage:
+        class MyFactory(BaseFactory[MyBaseClass]):
            pass

        @MyFactory.register("custom")
-        class CustomComponent(MyBase):
+        class CustomComponent(MyBaseClass):
            ...

-        obj = MyFactory.create("custom", *args, **kwargs)
-
-    ``create()`` filters kwargs to match the component's ``__init__``
-    signature so components don't need ``**kwargs`` just to absorb
-    unrelated parameters.
+        component = MyFactory.create("custom", *args, **kwargs)
    """

-    _entries: Dict[str, Type[T]]
+    _registry: Registry

    def __init_subclass__(cls, **kwargs):
        super().__init_subclass__(**kwargs)
-        for orig_base in getattr(cls, "__orig_bases__", ()):
-            if _get_origin(orig_base) is BaseFactory:
-                (arg,) = _get_args(orig_base)
-                cls._entries = {}
-                try:
-                    cls._component_base = _resolve_type(arg, cls)
-                except Exception:
-                    cls._component_base = None
-                return
+        cls._registry = Registry()

    @classmethod
-    def register(cls, name: str) -> Callable[[Type[T]], Type[T]]:
-        """Decorator to register a component class.
+    def register(
+        cls, name: str, category: Optional[str] = None, priority: int = 0
+    ) -> Callable[[Type[T]], Type[T]]:
+        """Decorator to register a component class with optional category and priority.

-        Validates that the decorated class inherits from the generic
-        type parameter ``T`` declared on the factory.
+        Args:
+            name: Registration name for the component
+            category: Optional category for grouping components
+            priority: Priority for ordering (default 0)
+
+        Returns:
+            Decorator function that registers the component class
+
+        Raises:
+            TypeError: If the decorated class doesn't inherit from the base type
        """

        def decorator(component_cls: Type[T]) -> Type[T]:
            cls._validate_component(component_cls)
-            if name in cls._entries:
-                raise ValueError(f"Component '{name}' is already registered")
-            cls._entries[name] = component_cls
+            cls._registry.register(
+                name, component_cls, category=category, priority=priority
+            )
            return component_cls

        return decorator

    @classmethod
    def create(cls, name: str, *args, **kwargs) -> T:
-        """Create a component instance by name, filtering kwargs to match
-        the component's ``__init__`` signature.
+        """Create a component instance by name.
+
+        Filters kwargs to match the component's __init__ signature,
+        so components don't need to declare **kwargs just to absorb
+        parameters meant for other components.
+
+        Args:
+            name: Registered name of the component
+            *args: Positional arguments passed to component constructor
+            **kwargs: Keyword arguments passed to component constructor
+
+        Returns:
+            Component instance
+
+        Raises:
+            ValueError: If the component name is not registered
        """
-        entry = cls._entries.get(name)
-        if entry is None:
+        if not cls._registry.contains(name):
            raise ValueError(
-                f"Unknown component: '{name}'. Supported types: {sorted(cls._entries)}"
+                f"Unknown component: '{name}'. "
+                f"Supported types: {sorted(cls._registry.list_names())}"
            )
-        component_cls = entry
+        component_cls = cls._registry.get(name)
        sig = inspect.signature(component_cls.__init__)
        has_var_kwargs = any(
            p.kind == inspect.Parameter.VAR_KEYWORD for p in sig.parameters.values()
@@ -115,33 +158,69 @@ class BaseFactory(ABC, Generic[T]):
        return component_cls(*args, **kwargs)

    @classmethod
-    def _validate_component(cls, component_cls: Type[T]):
-        """Validate the decorated class inherits from the factory's base type.
+    def _validate_component(cls, component_cls: Type[T]) -> None:
+        """Validate that the component class is valid for this factory.

-        Override for custom validation beyond ``issubclass``.
+        Override this method in subclasses to add custom validation.
+
+        Args:
+            component_cls: Component class to validate
+
+        Raises:
+            TypeError: If the component class is invalid
        """
-        base = cls._component_base
-        if base is not None and not issubclass(component_cls, base):
-            raise TypeError(
-                f"{component_cls.__name__} must inherit from {base.__name__}"
-            )
+        pass

    @classmethod
    def get_component_class(cls, name: str) -> Type[T]:
-        """Get the registered component class without instantiating it."""
-        entry = cls._entries.get(name)
-        if entry is None:
+        """Get the registered component class by name without instantiating it.
+
+        Args:
+            name: Registered name of the component
+
+        Returns:
+            The component class itself
+
+        Raises:
+            ValueError: If the component name is not registered
+        """
+        if not cls._registry.contains(name):
            raise ValueError(
-                f"Unknown component: '{name}'. Supported types: {sorted(cls._entries)}"
+                f"Unknown component: '{name}'. "
+                f"Supported types: {sorted(cls._registry.list_names())}"
            )
-        return entry
+        return cls._registry.get(name)

    @classmethod
-    def list_registered(cls) -> List[str]:
-        """List all registered component names."""
-        return sorted(cls._entries)
+    def list_registered(cls) -> list:
+        """List all registered component names.
+
+        Returns:
+            List of registered component names
+        """
+        return cls._registry.list_names()

    @classmethod
    def is_registered(cls, name: str) -> bool:
-        """Check if a component name is registered."""
-        return name in cls._entries
+        """Check if a component name is registered.
+
+        Args:
+            name: Component name to check
+
+        Returns:
+            True if registered, False otherwise
+        """
+        return cls._registry.contains(name)
+
+    @classmethod
+    def list_by_category(cls, category: str) -> List[str]:
+        """List registered component names in a category."""
+        return cls._registry.list_by_category(category)
+
+    @classmethod
+    def list_by_priority(cls, reverse: bool = False) -> List[str]:
+        """List registered component names sorted by priority."""
+        return cls._registry.list_by_priority(reverse)
+
+
+__all__ = ["Registry", "BaseFactory"]
@@ -1,43 +1,32 @@
 """Inference module for continuous batching.

 Layers:
-  - core/:        Core inference loop (cache, executor, scheduler, task)
-  - api/:         HTTP orchestration (ProtocolHandler, server)
-  - protocols/:   Response builders (OpenAI, Anthropic)
-  - transport/:   SSE transport utilities
-  - engine.py:    Facade (InferenceEngine), Value Object (GenerationRequest)
-  - sample.py:    Strategy pattern (TemperatureStrategy, TopKStrategy, TopPStrategy, FrequencyPenaltyStrategy)
+  - core/:           Core inference loop (cache, executor, scheduler, task)
+  - api/:            HTTP protocol handlers (OpenAI, Anthropic)
+  - engine.py:       Facade (InferenceEngine), Value Object (GenerationRequest)
+  - sample.py:       Strategy pattern (TemperatureStrategy, TopKStrategy, TopPStrategy)
 """

 from astrai.inference.api import (
+    AnthropicHandler,
    AnthropicMessage,
-    BaseToolParser,
    ChatCompletionRequest,
    ChatMessage,
-    FunctionDef,
-    GenContext,
    MessagesRequest,
+    OpenAIHandler,
    ProtocolHandler,
-    SimpleJsonToolParser,
    StopChecker,
-    ToolDef,
-    ToolParserFactory,
-    get_app,
+    StreamContext,
+    app,
    run_server,
 )
-from astrai.inference.api.anthropic import AnthropicResponseBuilder
-from astrai.inference.api.openai import OpenAIResponseBuilder
 from astrai.inference.core import (
    STOP,
    Allocator,
-    CacheView,
-    ContiguousCache,
-    ContiguousCacheView,
    Executor,
    InferenceScheduler,
    KVCache,
-    PageCache,
-    PageCacheView,
+    KvcacheView,
    PagePool,
    PrefixCache,
    Storage,
@@ -47,10 +36,12 @@ from astrai.inference.core import (
    TaskTable,
    page_hash,
 )
-from astrai.inference.engine import GenerationRequest, InferenceEngine
+from astrai.inference.engine import (
+    GenerationRequest,
+    InferenceEngine,
+)
 from astrai.inference.sample import (
    BaseSamplingStrategy,
-    FrequencyPenaltyStrategy,
    SamplingPipeline,
    TemperatureStrategy,
    TopKStrategy,
@@ -59,47 +50,43 @@ from astrai.inference.sample import (
 )

 __all__ = [
+    # Engine / Requests
    "InferenceEngine",
    "GenerationRequest",
+    # Core scheduler
    "InferenceScheduler",
    "Executor",
    "STOP",
    "Task",
    "TaskManager",
    "TaskStatus",
+    # Core cache
    "Allocator",
-    "CacheView",
    "KVCache",
-    "ContiguousCache",
-    "ContiguousCacheView",
-    "PageCache",
-    "PageCacheView",
+    "KvcacheView",
    "PagePool",
    "PrefixCache",
    "Storage",
    "TaskTable",
    "page_hash",
+    # Sampling (Strategy pattern)
    "sample",
    "BaseSamplingStrategy",
    "TemperatureStrategy",
    "TopKStrategy",
    "TopPStrategy",
-    "FrequencyPenaltyStrategy",
    "SamplingPipeline",
+    # Protocol
    "ProtocolHandler",
    "StopChecker",
-    "GenContext",
-    "BaseToolParser",
-    "SimpleJsonToolParser",
-    "ToolParserFactory",
-    "OpenAIResponseBuilder",
-    "AnthropicResponseBuilder",
+    "StreamContext",
+    "AnthropicHandler",
+    "OpenAIHandler",
+    # Server
    "ChatMessage",
    "ChatCompletionRequest",
-    "FunctionDef",
-    "ToolDef",
    "AnthropicMessage",
    "MessagesRequest",
-    "get_app",
+    "app",
    "run_server",
 ]
@@ -1,39 +1,31 @@
-"""Inference API: protocol handler, stop checker, tool parsers, and FastAPI server.
+"""Inference API: protocol handlers and FastAPI server."""

-``app`` is no longer a module-level global. Use :func:`get_app` to access the
-lazy singleton FastAPI instance.
-"""
-
-from astrai.inference.api.protocol import GenContext, ProtocolHandler, StopChecker
+from astrai.inference.api.protocol import (
+    AnthropicHandler,
+    OpenAIHandler,
+    ProtocolHandler,
+    StopChecker,
+    StreamContext,
+)
 from astrai.inference.api.server import (
    AnthropicMessage,
    ChatCompletionRequest,
    ChatMessage,
-    FunctionDef,
    MessagesRequest,
-    ToolDef,
-    get_app,
+    app,
    run_server,
 )
-from astrai.inference.api.tool_parser import (
-    BaseToolParser,
-    SimpleJsonToolParser,
-    ToolParserFactory,
-)

 __all__ = [
+    "AnthropicHandler",
+    "OpenAIHandler",
    "ProtocolHandler",
    "StopChecker",
-    "GenContext",
-    "BaseToolParser",
-    "SimpleJsonToolParser",
-    "ToolParserFactory",
+    "StreamContext",
    "AnthropicMessage",
    "ChatCompletionRequest",
    "ChatMessage",
-    "FunctionDef",
-    "ToolDef",
    "MessagesRequest",
-    "get_app",
+    "app",
    "run_server",
 ]
@@ -1,142 +0,0 @@
-"""Anthropic message completion response builder."""
-
-import time
-import uuid
-from typing import Any, Dict, List, Tuple, Union
-
-from pydantic import BaseModel
-
-from astrai.inference.api.protocol import (
-    GenContext,
-    ResponseBuilder,
-    StopInfo,
-    sse_event,
-)
-from astrai.inference.engine import InferenceEngine
-
-
-def _extract_text(content: Union[str, List[Dict[str, Any]]]) -> str:
-    if isinstance(content, str):
-        return content
-    if isinstance(content, list):
-        for block in content:
-            if isinstance(block, dict) and block.get("type") == "text":
-                return block.get("text", "")
-    return ""
-
-
-class AnthropicResponseBuilder(ResponseBuilder):
-    def prepare(
-        self, request: BaseModel, engine: InferenceEngine
-    ) -> Tuple[str, GenContext, List[str]]:
-        messages: List[Dict[str, str]] = []
-        system = getattr(request, "system", None)
-        if system:
-            messages.append({"role": "system", "content": system})
-        for m in request.messages:
-            text = _extract_text(m.content)
-            if text:
-                messages.append({"role": m.role, "content": text})
-        prompt = engine.tokenizer.apply_chat_template(messages, tokenize=False)
-        ctx = GenContext(
-            resp_id=f"msg_{uuid.uuid4().hex[:24]}",
-            created=int(time.time()),
-            model=request.model,
-        )
-        stop_sequences = getattr(request, "stop_sequences", None) or []
-        return prompt, ctx, stop_sequences
-
-    def format_stream_start(self, ctx: GenContext) -> List[str]:
-        return [
-            sse_event(
-                {
-                    "type": "message_start",
-                    "message": {
-                        "id": ctx.resp_id,
-                        "type": "message",
-                        "role": "assistant",
-                        "model": ctx.model,
-                        "content": [],
-                        "usage": {"input_tokens": ctx.prompt_tokens},
-                    },
-                },
-                event="message_start",
-            ),
-            sse_event(
-                {
-                    "type": "content_block_start",
-                    "index": 0,
-                    "content_block": {"type": "text", "text": ""},
-                },
-                event="content_block_start",
-            ),
-        ]
-
-    def format_chunk(self, token: str, **kwargs) -> List[str]:
-        return [
-            sse_event(
-                {
-                    "type": "content_block_delta",
-                    "index": 0,
-                    "delta": {"type": "text_delta", "text": token},
-                },
-                event="content_block_delta",
-            )
-        ]
-
-    def format_stream_end(self, ctx: GenContext, stop: StopInfo) -> List[str]:
-        events: List[str] = []
-        if stop.matched:
-            trimmed = stop.body[: stop.body.rfind(stop.matched)]
-            unyielded = trimmed[len(stop.yielded) :]
-            if unyielded:
-                events.append(
-                    sse_event(
-                        {
-                            "type": "content_block_delta",
-                            "index": 0,
-                            "delta": {"type": "text_delta", "text": unyielded},
-                        },
-                        event="content_block_delta",
-                    )
-                )
-        events.append(
-            sse_event(
-                {"type": "content_block_stop", "index": 0},
-                event="content_block_stop",
-            )
-        )
-        events.append(
-            sse_event(
-                {
-                    "type": "message_delta",
-                    "delta": {
-                        "stop_reason": "stop_sequence" if stop.matched else "end_turn",
-                        "stop_sequence": stop.matched,
-                    },
-                    "usage": {"output_tokens": ctx.completion_tokens},
-                },
-                event="message_delta",
-            )
-        )
-        events.append(sse_event({"type": "message_stop"}, event="message_stop"))
-        return events
-
-    def format_response(
-        self, ctx: GenContext, content: str, stop: StopInfo
-    ) -> Dict[str, Any]:
-        if stop.matched:
-            content = content[: content.rfind(stop.matched)]
-        return {
-            "id": ctx.resp_id,
-            "type": "message",
-            "role": "assistant",
-            "model": ctx.model,
-            "content": [{"type": "text", "text": content}],
-            "stop_reason": "stop_sequence" if stop.matched else "end_turn",
-            "stop_sequence": stop.matched,
-            "usage": {
-                "input_tokens": ctx.prompt_tokens,
-                "output_tokens": ctx.completion_tokens,
-            },
-        }
@@ -1,277 +0,0 @@
-"""OpenAI chat completion response builder."""
-
-import logging
-import time
-import uuid
-from typing import Any, Dict, List, Optional, Tuple, Union
-
-from pydantic import BaseModel
-
-from astrai.inference.api.protocol import (
-    GenContext,
-    ResponseBuilder,
-    StopInfo,
-    sse_event,
-)
-from astrai.inference.api.tool_parser import BaseToolParser, ToolParserFactory
-from astrai.inference.engine import InferenceEngine
-
-logger = logging.getLogger(__name__)
-
-_UNSUPPORTED_PARAMS = (
-    "n",
-    "presence_penalty",
-    "logit_bias",
-    "user",
-)
-
-
-def _resolve_tool_choice(
-    request: BaseModel,
-) -> Union[str, Dict[str, Any]]:
-    tc = getattr(request, "tool_choice", None)
-    if tc is None:
-        return "auto"
-    if isinstance(tc, str):
-        return tc
-    if isinstance(tc, dict):
-        return tc
-    return "auto"
-
-
-def _resolve_tools(request: BaseModel) -> Optional[List[Dict[str, Any]]]:
-    raw = getattr(request, "tools", None)
-    if not raw:
-        return None
-    if isinstance(raw, list):
-        return [t.model_dump() if hasattr(t, "model_dump") else t for t in raw]
-    return None
-
-
-class OpenAIResponseBuilder(ResponseBuilder):
-    def prepare(
-        self, request: BaseModel, engine: InferenceEngine
-    ) -> Tuple[str, GenContext, List[str]]:
-        messages = [{"role": m.role, "content": m.content} for m in request.messages]
-        tools = _resolve_tools(request)
-        prompt = engine.tokenizer.apply_chat_template(
-            messages, tokenize=False, tools=tools or []
-        )
-
-        self._resp_id = f"chatcmpl-{uuid.uuid4().hex[:12]}"
-        self._model = request.model
-
-        for param in _UNSUPPORTED_PARAMS:
-            value = getattr(request, param, None)
-            fields = getattr(type(request), "model_fields", {})
-            default = fields[param].default if param in fields else None
-            if value is not None and value != default:
-                logger.warning(
-                    "ChatCompletionRequest param '%s'=%r is not supported"
-                    " and will be ignored",
-                    param,
-                    value,
-                )
-
-        self._parser: Optional[BaseToolParser] = None
-        if tools:
-            tool_choice = _resolve_tool_choice(request)
-            self._parser = ToolParserFactory.create(
-                "simple_json", tools=tools, tool_choice=tool_choice
-            )
-        self._content_started = False
-
-        ctx = GenContext(
-            resp_id=self._resp_id,
-            created=int(time.time()),
-            model=self._model,
-        )
-        stop = request.stop
-        stop_sequences = (
-            [] if stop is None else [stop] if isinstance(stop, str) else stop
-        )
-        return prompt, ctx, stop_sequences
-
-    def format_stream_start(self, ctx: GenContext) -> List[str]:
-        return [
-            sse_event(
-                {
-                    "id": self._resp_id,
-                    "object": "chat.completion.chunk",
-                    "created": ctx.created,
-                    "model": self._model,
-                    "choices": [
-                        {
-                            "index": 0,
-                            "delta": {"role": "assistant"},
-                            "finish_reason": None,
-                        }
-                    ],
-                }
-            )
-        ]
-
-    def format_chunk(self, token: str, **kwargs) -> List[str]:
-        body = kwargs.get("body", "")
-        if self._parser is not None:
-            return self._format_tool_chunk(body, **kwargs)
-
-        return [
-            sse_event(
-                {
-                    "id": self._resp_id,
-                    "object": "chat.completion.chunk",
-                    "created": 0,
-                    "model": self._model,
-                    "choices": [
-                        {
-                            "index": 0,
-                            "delta": {"content": token},
-                            "finish_reason": None,
-                        }
-                    ],
-                }
-            )
-        ]
-
-    def _format_tool_chunk(self, body: str, **kwargs) -> List[str]:
-        deltas = self._parser.feed(
-            body,
-            current_token_ids=kwargs.get("current_token_ids"),
-            delta_token_ids=kwargs.get("delta_token_ids"),
-        )
-        events: List[str] = []
-        for d in deltas:
-            if "content" in d:
-                if not self._content_started:
-                    events.append(self._role_chunk())
-                    self._content_started = True
-                events.append(
-                    sse_event(
-                        {
-                            "id": self._resp_id,
-                            "object": "chat.completion.chunk",
-                            "created": 0,
-                            "model": self._model,
-                            "choices": [
-                                {
-                                    "index": 0,
-                                    "delta": {"content": d["content"]},
-                                    "finish_reason": None,
-                                }
-                            ],
-                        }
-                    )
-                )
-            elif "tool_calls" in d:
-                if not self._content_started:
-                    events.append(self._role_chunk())
-                    self._content_started = True
-                events.append(
-                    sse_event(
-                        {
-                            "id": self._resp_id,
-                            "object": "chat.completion.chunk",
-                            "created": 0,
-                            "model": self._model,
-                            "choices": [
-                                {
-                                    "index": 0,
-                                    "delta": {"tool_calls": d["tool_calls"]},
-                                    "finish_reason": None,
-                                }
-                            ],
-                        }
-                    )
-                )
-        return events
-
-    def _role_chunk(self) -> str:
-        return sse_event(
-            {
-                "id": self._resp_id,
-                "object": "chat.completion.chunk",
-                "created": 0,
-                "model": self._model,
-                "choices": [
-                    {
-                        "index": 0,
-                        "delta": {"role": "assistant"},
-                        "finish_reason": None,
-                    }
-                ],
-            }
-        )
-
-    def format_stream_end(self, ctx: GenContext, stop: StopInfo) -> List[str]:
-        finish_reason = "stop"
-        if self._parser is not None and self._parser.has_tool_calls:
-            finish_reason = "tool_calls"
-        return [
-            sse_event(
-                {
-                    "id": self._resp_id,
-                    "object": "chat.completion.chunk",
-                    "created": ctx.created,
-                    "model": self._model,
-                    "choices": [
-                        {"index": 0, "delta": {}, "finish_reason": finish_reason}
-                    ],
-                }
-            ),
-            sse_event(
-                {
-                    "prompt_tokens": ctx.prompt_tokens,
-                    "completion_tokens": ctx.completion_tokens,
-                    "total_tokens": ctx.prompt_tokens + ctx.completion_tokens,
-                }
-            ),
-        ]
-
-    def format_response(
-        self, ctx: GenContext, content: str, stop: StopInfo
-    ) -> Dict[str, Any]:
-        if self._parser is not None:
-            parsed = self._parser.parse_complete(content)
-            if parsed and parsed.get("tool_calls"):
-                return {
-                    "id": self._resp_id,
-                    "object": "chat.completion",
-                    "created": ctx.created,
-                    "model": self._model,
-                    "choices": [
-                        {
-                            "index": 0,
-                            "message": {
-                                "role": "assistant",
-                                "content": parsed.get("content"),
-                                "tool_calls": parsed["tool_calls"],
-                            },
-                            "finish_reason": "tool_calls",
-                        }
-                    ],
-                    "usage": {
-                        "prompt_tokens": ctx.prompt_tokens,
-                        "completion_tokens": ctx.completion_tokens,
-                        "total_tokens": ctx.prompt_tokens + ctx.completion_tokens,
-                    },
-                }
-
-        return {
-            "id": self._resp_id,
-            "object": "chat.completion",
-            "created": ctx.created,
-            "model": self._model,
-            "choices": [
-                {
-                    "index": 0,
-                    "message": {"role": "assistant", "content": content},
-                    "finish_reason": "stop",
-                }
-            ],
-            "usage": {
-                "prompt_tokens": ctx.prompt_tokens,
-                "completion_tokens": ctx.completion_tokens,
-                "total_tokens": ctx.prompt_tokens + ctx.completion_tokens,
-            },
-        }
@@ -1,13 +1,15 @@
-"""Orchestration layer: ProtocolHandler, StopChecker, GenContext, StopInfo, ResponseBuilder, SSE utils.
+"""Protocol handlers for OpenAI and Anthropic chat completion APIs.

-ProtocolHandler orchestrates the async generation loop and delegates
-protocol-specific formatting to a ResponseBuilder.
+Template Method + Builder patterns eliminate the 45% code duplication between
+stream/non-stream branches and across protocol adapters.
 """

 import json
+import time
+import uuid
 from abc import ABC, abstractmethod
 from dataclasses import dataclass
-from typing import Any, AsyncGenerator, Dict, List, Optional, Tuple, Union
+from typing import Any, Dict, List, Optional, Union

 from fastapi.responses import StreamingResponse
 from pydantic import BaseModel
@@ -15,7 +17,7 @@ from pydantic import BaseModel
 from astrai.inference.engine import InferenceEngine


-def sse_event(data: Dict[str, Any], event: Optional[str] = None) -> str:
+def _sse_event(data: Dict[str, Any], event: Optional[str] = None) -> str:
    lines: List[str] = []
    if event:
        lines.append(f"event: {event}")
@@ -24,28 +26,22 @@ def sse_event(data: Dict[str, Any], event: Optional[str] = None) -> str:
    return "\n".join(lines)


-def sse_done() -> str:
+def _sse_done() -> str:
    return "data: [DONE]\n\n"


@dataclass
-class GenContext:
-    """Per-generation metadata passed to builder format methods."""
+class StreamContext:
+    """Shared state across the streaming generation lifecycle."""

    resp_id: str
    created: int
    model: str
-    prompt_tokens: int = 0
+    prompt_tokens: int
    completion_tokens: int = 0
-
-
-@dataclass
-class StopInfo:
-    """Stop-check result passed to format_stream_end / format_response."""
-
-    matched: Optional[str] = None
-    body: str = ""
-    yielded: str = ""
+    accumulated: str = ""
+    stop_matched: Optional[str] = None
+    last_yield_trimmed: str = ""


 class StopChecker:
@@ -60,116 +56,129 @@ class StopChecker:
                return seq
        return None

+    def trim(self, text: str, matched: str) -> str:
+        idx = text.rfind(matched)
+        return text[:idx] if idx != -1 else text

-class ResponseBuilder(ABC):
-    """Interface for protocol-specific response formatting.
+    @property
+    def has_sequences(self) -> bool:
+        return len(self._sequences) > 0

-    A new protocol requires one concrete builder implementing 5 methods.
+
+class ProtocolHandler(ABC):
+    """Template-method base for API protocol handlers.
+
+    Subclasses implement format hooks; the base class orchestrates the
+    generate-async loop and SSE/JSON response construction.
+
+    Lifecycle::
+
+        handle()
+          ├─ build_prompt()          # protocol-specific prompt assembly
+          ├─ create_response_id()    # unique response identifier
+          ├─ [stream]
+          │   ├─ format_stream_start()
+          │   ├─ format_stream_token()  × N
+          │   │   └─ on_token() hook for stop-sequence interception
+          │   └─ format_stream_end()
+          └─ [non-stream]
+              ├─ (accumulate tokens)
+              └─ format_non_stream_response()
    """

-    @abstractmethod
-    def prepare(
-        self, request: BaseModel, engine: InferenceEngine
-    ) -> Tuple[str, GenContext, List[str]]:
-        """Return (prompt, ctx, stop_sequences) for a generation request."""
+    request_model: type[BaseModel]

-    @abstractmethod
-    def format_stream_start(self, ctx: GenContext) -> List[str]:
-        """SSE events that open the stream."""
-
-    @abstractmethod
-    def format_chunk(self, token: str, **kwargs) -> List[str]:
-        """SSE events for a single generated token.
-
-        ``body`` (the full accumulated text so far) is always provided
-        as a keyword argument. Additional keyword arguments such as
-        ``current_token_ids`` and ``delta_token_ids`` may be included
-        for tool parsers that need token-level information.
-        Returns a list of SSE event strings (may be empty).
-        """
-
-    @abstractmethod
-    def format_stream_end(self, ctx: GenContext, stop: StopInfo) -> List[str]:
-        """SSE events that close the stream."""
-
-    @abstractmethod
-    def format_response(
-        self, ctx: GenContext, content: str, stop: StopInfo
-    ) -> Dict[str, Any]:
-        """JSON response body for non-streaming mode."""
-
-
-class ProtocolHandler:
-    """Orchestrates the generation loop, delegates formatting to a builder.
-
-    Usage::
-
-        handler = ProtocolHandler(request, engine, OpenAIResponseBuilder())
-        response = await handler.handle()
-    """
-
-    def __init__(
-        self, request: BaseModel, engine: InferenceEngine, builder: ResponseBuilder
-    ):
+    def __init__(self, request: BaseModel, engine: InferenceEngine):
        self.request = request
        self.engine = engine
-        self.builder = builder
+
+    @abstractmethod
+    def build_prompt(self) -> str:
+        """Build the full prompt string from the request messages."""
+
+    @abstractmethod
+    def create_response_id(self) -> str:
+        """Generate a unique response ID following the protocol convention."""
+
+    @abstractmethod
+    def format_stream_start(self, ctx: StreamContext) -> List[str]:
+        """Yield SSE events that open the stream (role marker, metadata)."""
+
+    @abstractmethod
+    def format_stream_token(self, ctx: StreamContext, token: str) -> str:
+        """Yield an SSE event for a single generated token."""
+
+    @abstractmethod
+    def format_stream_end(self, ctx: StreamContext) -> List[str]:
+        """Yield SSE events that close the stream (finish reason, usage stats)."""
+
+    @abstractmethod
+    def format_non_stream_response(
+        self, ctx: StreamContext, content: str
+    ) -> Dict[str, Any]:
+        """Build the JSON response body for non-streaming mode."""
+
+    def get_stop_sequences(self) -> List[str]:
+        return []
+
+    def create_stop_checker(self) -> StopChecker:
+        return StopChecker(self.get_stop_sequences())
+
+    def on_token(
+        self, ctx: StreamContext, token: str, stop_checker: StopChecker
+    ) -> Optional[str]:
+        """Hook after each token is appended to accumulated.
+
+        Return a matched stop-sequence string to break the loop,
+        or None to continue.
+
+        """
+        return None

    async def handle(self) -> Union[StreamingResponse, Dict[str, Any]]:
-        prompt, ctx, stop_sequences = self.builder.prepare(self.request, self.engine)
-        ctx.prompt_tokens = len(self.engine.tokenizer.encode(prompt))
+        ctx = StreamContext(
+            resp_id=self.create_response_id(),
+            created=int(time.time()),
+            model=self.request.model,
+            prompt_tokens=self._count_prompt_tokens(),
+        )

        agen = self.engine.generate_async(
-            prompt=prompt,
+            prompt=self.build_prompt(),
            max_tokens=self.request.max_tokens,
            temperature=self.request.temperature,
            top_p=self.request.top_p,
            top_k=self.request.top_k,
-            frequency_penalty=getattr(self.request, "frequency_penalty", 0.0),
        )

        if self.request.stream:
-            return self._handle_stream(agen, ctx, stop_sequences)
+            return self._handle_stream(agen, ctx)
        else:
-            return await self._handle_non_stream(agen, ctx, stop_sequences)
+            return await self._handle_non_stream(agen, ctx)

-    def _handle_stream(
-        self, agen: AsyncGenerator, ctx: GenContext, stop_sequences: List[str]
-    ) -> StreamingResponse:
-        checker = StopChecker(stop_sequences)
+    def _count_prompt_tokens(self) -> int:
+        return len(self.engine.tokenizer.encode(self.build_prompt()))
+
+    def _handle_stream(self, agen, ctx: StreamContext) -> StreamingResponse:
+        stop_checker = self.create_stop_checker()

        async def event_stream():
-            for event in self.builder.format_stream_start(ctx):
+            for event in self.format_stream_start(ctx):
                yield event

-            body = ""
-            yielded = ""
-            matched = None
-            token_ids: List[int] = []
            async for token in agen:
-                body += token
+                ctx.completion_tokens += 1
+                ctx.accumulated += token

-                new_ids = self.engine.tokenizer.encode(token)
-                token_ids.extend(new_ids)
-
-                matched = checker.check(body)
+                matched = self.on_token(ctx, token, stop_checker)
                if matched:
                    break

-                ctx.completion_tokens += 1
-                for event in self.builder.format_chunk(
-                    token,
-                    body=body,
-                    current_token_ids=token_ids,
-                    delta_token_ids=new_ids,
-                ):
-                    yield event
-                yielded += token
+                yield self.format_stream_token(ctx, token)

-            stop = StopInfo(matched=matched, body=body, yielded=yielded)
-            for event in self.builder.format_stream_end(ctx, stop):
+            for event in self.format_stream_end(ctx):
                yield event
-            yield sse_done()
+            yield _sse_done()

        return StreamingResponse(
            event_stream(),
@@ -177,24 +186,260 @@ class ProtocolHandler:
            headers={"Cache-Control": "no-cache", "Connection": "keep-alive"},
        )

-    async def _handle_non_stream(
-        self, agen: AsyncGenerator, ctx: GenContext, stop_sequences: List[str]
-    ) -> Dict[str, Any]:
-        checker = StopChecker(stop_sequences)
+    async def _handle_non_stream(self, agen, ctx: StreamContext) -> Dict[str, Any]:
+        stop_checker = self.create_stop_checker()
        chunks: List[str] = []
-        body = ""
-        matched = None

        async for token in agen:
+            ctx.completion_tokens += 1
+            ctx.accumulated += token
            chunks.append(token)
-            body += token

-            matched = checker.check(body)
+            matched = self.on_token(ctx, token, stop_checker)
            if matched:
                break

-            ctx.completion_tokens += 1
-
        content = "".join(chunks)
-        stop = StopInfo(matched=matched, body=body)
-        return self.builder.format_response(ctx, content, stop)
+        return self.format_non_stream_response(ctx, content)
+
+
+def _extract_text_content(content: Union[str, List[Dict[str, Any]]]) -> str:
+    """Extract plain text from an Anthropic content block (string or list)."""
+    if isinstance(content, str):
+        return content
+    if isinstance(content, list):
+        for block in content:
+            if isinstance(block, dict) and block.get("type") == "text":
+                return block.get("text", "")
+    return ""
+
+
+class OpenAIHandler(ProtocolHandler):
+    """OpenAI-compatible /v1/chat/completions handler."""
+
+    def build_prompt(self) -> str:
+        messages = [
+            {"role": m.role, "content": m.content} for m in self.request.messages
+        ]
+        return self.engine.tokenizer.apply_chat_template(messages, tokenize=False)
+
+    def create_response_id(self) -> str:
+        return f"chatcmpl-{uuid.uuid4().hex[:12]}"
+
+    def get_stop_sequences(self) -> List[str]:
+        stop = self.request.stop
+        if stop is None:
+            return []
+        return [stop] if isinstance(stop, str) else stop
+
+    def on_token(
+        self, ctx: StreamContext, token: str, stop_checker: StopChecker
+    ) -> Optional[str]:
+        return stop_checker.check(ctx.accumulated)
+
+    def format_stream_start(self, ctx: StreamContext) -> List[str]:
+        return [
+            _sse_event(
+                {
+                    "id": ctx.resp_id,
+                    "object": "chat.completion.chunk",
+                    "created": ctx.created,
+                    "model": ctx.model,
+                    "choices": [
+                        {
+                            "index": 0,
+                            "delta": {"role": "assistant"},
+                            "finish_reason": None,
+                        }
+                    ],
+                }
+            )
+        ]
+
+    def format_stream_token(self, ctx: StreamContext, token: str) -> str:
+        return _sse_event(
+            {
+                "id": ctx.resp_id,
+                "object": "chat.completion.chunk",
+                "created": ctx.created,
+                "model": ctx.model,
+                "choices": [
+                    {"index": 0, "delta": {"content": token}, "finish_reason": None}
+                ],
+            }
+        )
+
+    def format_stream_end(self, ctx: StreamContext) -> List[str]:
+        return [
+            _sse_event(
+                {
+                    "id": ctx.resp_id,
+                    "object": "chat.completion.chunk",
+                    "created": ctx.created,
+                    "model": ctx.model,
+                    "choices": [{"index": 0, "delta": {}, "finish_reason": "stop"}],
+                }
+            ),
+            _sse_event(
+                {
+                    "prompt_tokens": ctx.prompt_tokens,
+                    "completion_tokens": ctx.completion_tokens,
+                    "total_tokens": ctx.prompt_tokens + ctx.completion_tokens,
+                }
+            ),
+        ]
+
+    def format_non_stream_response(
+        self, ctx: StreamContext, content: str
+    ) -> Dict[str, Any]:
+        return {
+            "id": ctx.resp_id,
+            "object": "chat.completion",
+            "created": ctx.created,
+            "model": ctx.model,
+            "choices": [
+                {
+                    "index": 0,
+                    "message": {"role": "assistant", "content": content},
+                    "finish_reason": "stop",
+                }
+            ],
+            "usage": {
+                "prompt_tokens": ctx.prompt_tokens,
+                "completion_tokens": ctx.completion_tokens,
+                "total_tokens": ctx.prompt_tokens + ctx.completion_tokens,
+            },
+        }
+
+
+class AnthropicHandler(ProtocolHandler):
+    """Anthropic-compatible /v1/messages handler."""
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self._yielded = ""
+
+    def build_prompt(self) -> str:
+        messages: List[Dict[str, str]] = []
+        system = getattr(self.request, "system", None)
+        if system:
+            messages.append({"role": "system", "content": system})
+        for m in self.request.messages:
+            content = _extract_text_content(m.content)
+            if content:
+                messages.append({"role": m.role, "content": content})
+        return self.engine.tokenizer.apply_chat_template(messages, tokenize=False)
+
+    def create_response_id(self) -> str:
+        return f"msg_{uuid.uuid4().hex[:24]}"
+
+    def get_stop_sequences(self) -> List[str]:
+        return getattr(self.request, "stop_sequences", None) or []
+
+    def on_token(
+        self, ctx: StreamContext, token: str, stop_checker: StopChecker
+    ) -> Optional[str]:
+        matched = stop_checker.check(ctx.accumulated)
+        if not matched:
+            return None
+
+        ctx.stop_matched = matched
+        trimmed = ctx.accumulated[: ctx.accumulated.rfind(matched)]
+        unyielded = trimmed[len(self._yielded) :]
+        if unyielded:
+            ctx.last_yield_trimmed = unyielded
+        return matched
+
+    def format_stream_start(self, ctx: StreamContext) -> List[str]:
+        return [
+            _sse_event(
+                {
+                    "type": "message_start",
+                    "message": {
+                        "id": ctx.resp_id,
+                        "type": "message",
+                        "role": "assistant",
+                        "model": ctx.model,
+                        "content": [],
+                        "usage": {"input_tokens": ctx.prompt_tokens},
+                    },
+                },
+                event="message_start",
+            ),
+            _sse_event(
+                {
+                    "type": "content_block_start",
+                    "index": 0,
+                    "content_block": {"type": "text", "text": ""},
+                },
+                event="content_block_start",
+            ),
+        ]
+
+    def format_stream_token(self, ctx: StreamContext, token: str) -> str:
+        self._yielded += token
+        return _sse_event(
+            {
+                "type": "content_block_delta",
+                "index": 0,
+                "delta": {"type": "text_delta", "text": token},
+            },
+            event="content_block_delta",
+        )
+
+    def format_stream_end(self, ctx: StreamContext) -> List[str]:
+        matched = ctx.stop_matched
+        events: List[str] = []
+        last_yielded = ctx.last_yield_trimmed
+        if last_yielded:
+            events.append(
+                _sse_event(
+                    {
+                        "type": "content_block_delta",
+                        "index": 0,
+                        "delta": {"type": "text_delta", "text": last_yielded},
+                    },
+                    event="content_block_delta",
+                )
+            )
+        events.append(
+            _sse_event(
+                {"type": "content_block_stop", "index": 0},
+                event="content_block_stop",
+            )
+        )
+        events.append(
+            _sse_event(
+                {
+                    "type": "message_delta",
+                    "delta": {
+                        "stop_reason": "stop_sequence" if matched else "end_turn",
+                        "stop_sequence": matched,
+                    },
+                    "usage": {"output_tokens": ctx.completion_tokens},
+                },
+                event="message_delta",
+            )
+        )
+        events.append(_sse_event({"type": "message_stop"}, event="message_stop"))
+        return events
+
+    def format_non_stream_response(
+        self, ctx: StreamContext, content: str
+    ) -> Dict[str, Any]:
+        matched = ctx.stop_matched
+        if matched:
+            content = content[: content.rfind(matched)]
+        return {
+            "id": ctx.resp_id,
+            "type": "message",
+            "role": "assistant",
+            "model": ctx.model,
+            "content": [{"type": "text", "text": content}],
+            "stop_reason": "stop_sequence" if matched else "end_turn",
+            "stop_sequence": matched,
+            "usage": {
+                "input_tokens": ctx.prompt_tokens,
+                "output_tokens": ctx.completion_tokens,
+            },
+        }
@@ -3,9 +3,6 @@ OpenAI / Anthropic-compatible chat completion server backed by continuous-batchi

 Protocol-specific formatting is delegated to ``astrai.inference.protocol``.
 This module owns the FastAPI app, request/response schemas, and dependency wiring.
-
-``app`` is lazily constructed — importing this module does NOT create a FastAPI instance.
-Use :func:`get_app` to access the singleton.
 """

 import logging
@@ -15,37 +12,22 @@ from typing import Any, Dict, List, Optional, Union

 import torch
 import uvicorn
-from fastapi import APIRouter, FastAPI, HTTPException
+from fastapi import FastAPI, HTTPException
 from pydantic import BaseModel, Field

-from astrai.inference.api.anthropic import AnthropicResponseBuilder
-from astrai.inference.api.openai import OpenAIResponseBuilder
-from astrai.inference.api.protocol import ProtocolHandler
+from astrai.inference.api.protocol import AnthropicHandler, OpenAIHandler
 from astrai.inference.engine import InferenceEngine
 from astrai.model import AutoModel
 from astrai.tokenize import AutoTokenizer

 logger = logging.getLogger(__name__)

-_app_instance: Optional[FastAPI] = None
+_project_root = Path(__file__).parent.parent.parent


 class ChatMessage(BaseModel):
    role: str
-    content: Optional[str] = None
-    tool_calls: Optional[List[Dict[str, Any]]] = None
-    tool_call_id: Optional[str] = None
-
-
-class FunctionDef(BaseModel):
-    name: str
-    description: Optional[str] = None
-    parameters: Optional[Dict[str, Any]] = None
-
-
-class ToolDef(BaseModel):
-    type: str = "function"
-    function: FunctionDef
+    content: str


 class ChatCompletionRequest(BaseModel):
@@ -64,8 +46,6 @@ class ChatCompletionRequest(BaseModel):
    frequency_penalty: Optional[float] = Field(default=0.0, ge=-2.0, le=2.0)
    logit_bias: Optional[Dict[int, float]] = None
    user: Optional[str] = None
-    tools: Optional[List[ToolDef]] = None
-    tool_choice: Optional[Union[str, Dict[str, Any]]] = "auto"


 class AnthropicMessage(BaseModel):
@@ -102,15 +82,17 @@ async def lifespan(app: FastAPI):
        logger.info("Inference engine shutdown complete")


-router = APIRouter()
+app = FastAPI(title="AstrAI Inference Server", version="0.2.0", lifespan=lifespan)


 def _create_engine(
-    param_path: Path,
+    param_path: Optional[Path] = None,
    device: str = "cuda",
    dtype: torch.dtype = torch.bfloat16,
    max_batch_size: int = 16,
 ) -> InferenceEngine:
+    if param_path is None:
+        param_path = _project_root / "params"
    if not param_path.exists():
        raise FileNotFoundError(f"Parameter directory not found: {param_path}")

@@ -128,66 +110,49 @@ def _create_engine(
    return engine


-def get_app() -> FastAPI:
-    """Return the singleton FastAPI instance (lazily created on first call)."""
-    global _app_instance
-    if _app_instance is None:
-        _app_instance = FastAPI(
-            title="AstrAI Inference Server",
-            version="0.2.0",
-            lifespan=lifespan,
-        )
-        _app_instance.include_router(router)
-        _app_instance.state.server_config = {}
-        _app_instance.state.engine = None
-    return _app_instance
-
-
 def _get_engine() -> InferenceEngine:
-    engine = get_app().state.engine
+    engine = app.state.engine
    if engine is None:
        raise HTTPException(status_code=503, detail="Engine not initialized")
    return engine


-@router.get("/health")
+@app.get("/health")
 async def health():
-    app = get_app()
    return {
        "status": "ok",
        "model_loaded": app.state.engine is not None,
    }


-@router.get("/stats")
+@app.get("/stats")
 async def get_stats():
    return _get_engine().get_stats()


-@router.post("/v1/chat/completions")
+@app.post("/v1/chat/completions")
 async def chat_completion(request: ChatCompletionRequest):
    engine = _get_engine()
-    handler = ProtocolHandler(request, engine, OpenAIResponseBuilder())
+    handler = OpenAIHandler(request, engine)
    return await handler.handle()


-@router.post("/v1/messages")
+@app.post("/v1/messages")
 async def create_message(request: MessagesRequest):
    engine = _get_engine()
-    handler = ProtocolHandler(request, engine, AnthropicResponseBuilder())
+    handler = AnthropicHandler(request, engine)
    return await handler.handle()


 def run_server(
-    param_path: Path,
    host: str = "0.0.0.0",
    port: int = 8000,
    reload: bool = False,
    device: str = "cuda",
    dtype: torch.dtype = torch.bfloat16,
+    param_path: Optional[Path] = None,
    max_batch_size: int = 16,
 ):
-    app = get_app()
    app.state.server_config = {
        "device": device,
        "dtype": dtype,
@@ -1,344 +0,0 @@
-"""Tool call parsers for extracting structured tool calls from model output.
-
-Patterned after vLLM's ToolParser abstraction. Each parser knows how to
-detect and incrementally extract tool calls from raw generated text.
-
-Subclasses may optionally consume ``token_ids`` for token-level parsing
-(e.g. Harmony / VLM-style parsers).
-"""
-
-import json
-import re
-import uuid
-from abc import ABC, abstractmethod
-from typing import Dict, List, Optional
-
-from astrai.factory import BaseFactory
-
-
-class BaseToolParser(ABC):
-    """Abstract tool call parser — one instance per request.
-
-    Maintains streaming state internally so that each call to :meth:`feed`
-    can diff against previously emitted content.
-
-    Parameters
-    ----------
-    tools : list of dict, optional
-        Tool definitions from the request.
-    tool_choice : str
-        ``"auto"`` / ``"required"`` / ``"none"`` or a named tool choice
-        dict.
-    """
-
-    def __init__(self, tools: Optional[List[Dict]] = None, tool_choice: str = "auto"):
-        self.tools = tools or []
-        self.tool_choice = tool_choice
-
-    @abstractmethod
-    def feed(
-        self,
-        body: str,
-        current_token_ids: Optional[List[int]] = None,
-        delta_token_ids: Optional[List[int]] = None,
-    ) -> List[Dict]:
-        """Feed the *full* accumulated text each step.
-
-        Returns a list of delta dicts to emit. Each delta is one of:
-
-        - ``{"content": "text"}``      — plain text delta
-        - ``{"tool_calls": [...]}``    — tool-call delta (OpenAI format)
-
-        Returns an empty list when nothing new should be emitted.
-
-        Parameters
-        ----------
-        body : str
-            The complete accumulated generated text so far.
-        current_token_ids : list of int, optional
-            All token IDs decoded into *body* (cumulative).
-        delta_token_ids : list of int, optional
-            Only the token IDs for this chunk.
-        """
-
-    @abstractmethod
-    def parse_complete(self, body: str) -> Optional[Dict]:
-        """Parse the *complete* generated text after generation ends.
-
-        Returns ``None`` when no tool calls were found, otherwise a dict
-        with ``content`` (str or None) and ``tool_calls`` (list of dicts).
-        """
-
-    @property
-    @abstractmethod
-    def has_tool_calls(self) -> bool:
-        """True if the parser detected at least one tool call in the stream."""
-
-
-class ToolParserFactory(BaseFactory["BaseToolParser"]):
-    pass
-
-
-_TOOL_CALL_HEAD_RE = re.compile(r'\{\s*"name"\s*:')
-
-
-def _scan_json(text: str, start: int = 0):
-    """Scan for a complete JSON object starting at *start*.
-
-    Returns ``(end, complete)`` where *end* is one-past the closing
-    brace (or ``len(text)`` if unclosed), and *complete* is a bool.
-    """
-    depth = 0
-    in_string = False
-    escape = False
-    for i in range(start, len(text)):
-        c = text[i]
-        if escape:
-            escape = False
-            continue
-        if c == "\\":
-            escape = True
-            continue
-        if c == '"':
-            in_string = not in_string
-            continue
-        if in_string:
-            continue
-        if c == "{":
-            depth += 1
-        elif c == "}":
-            depth -= 1
-            if depth == 0:
-                return i + 1, True
-    return len(text), False
-
-
-def _parse_tool_call_json(json_str: str, complete: bool):
-    """Extract *name* and *arguments* from a tool-call JSON string.
-
-    Returns ``(name, args, valid)``.
-    """
-    if complete:
-        try:
-            obj = json.loads(json_str)
-        except json.JSONDecodeError:
-            return None, "", False
-        name = obj.get("name")
-        if not isinstance(name, str) or not name:
-            return None, "", False
-        args = obj.get("arguments")
-        if isinstance(args, dict):
-            if not args:
-                args = ""
-            else:
-                args = json.dumps(args, ensure_ascii=False)
-                args = args[1:-1].rstrip()
-        elif isinstance(args, list):
-            args = json.dumps(args, ensure_ascii=False) if args else ""
-        elif isinstance(args, str):
-            pass
-        else:
-            args = str(args) if args is not None else ""
-        return name, args, True
-
-    name_match = re.search(r'"name"\s*:\s*"([^"]*)"', json_str)
-    if not name_match:
-        return None, "", False
-    name = name_match.group(1)
-
-    args_match = re.search(r'"arguments"\s*:\s*(.*)', json_str, re.DOTALL)
-    if not args_match:
-        return name, "", True
-
-    raw = args_match.group(1).rstrip()
-    if raw.startswith("{"):
-        inner = raw[1:].rstrip()
-        if inner.endswith("}"):
-            inner = inner[:-1].rstrip()
-        raw = inner
-    return name, raw, True
-
-
-def _find_tool_calls(text: str, start_pos: int = 0):
-    """Find all complete ``{...}`` tool-call objects in *text*.
-
-    Returns a list of dicts with keys *start*, *end*, *name*, *args*,
-    *complete*.
-    """
-    results = []
-    pos = start_pos
-
-    while True:
-        brace = text.find("{", pos)
-        if brace == -1:
-            break
-
-        end, complete = _scan_json(text, brace)
-        if not complete:
-            break
-
-        json_str = text[brace:end]
-
-        name, args, valid = _parse_tool_call_json(json_str, complete=True)
-        if not valid or name is None:
-            pos = end
-            continue
-
-        results.append(
-            {
-                "start": brace,
-                "end": end,
-                "name": name,
-                "args": args,
-                "complete": True,
-            }
-        )
-        pos = end
-
-    return results
-
-
-def _find_partial_tool_call(text: str, start_pos: int = 0):
-    """Find one incomplete (still-generating) tool-call JSON object."""
-    brace = text.find("{", start_pos)
-    if brace == -1:
-        return None
-
-    json_str = text[brace:]
-    if '"name"' not in json_str:
-        return None
-
-    name, args, valid = _parse_tool_call_json(json_str, complete=False)
-    if not valid or name is None:
-        return None
-
-    return {
-        "start": brace,
-        "name": name,
-        "args": args,
-        "complete": False,
-    }
-
-
-@ToolParserFactory.register("simple_json")
-class SimpleJsonToolParser(BaseToolParser):
-    """Parser for models that output tool calls as plain JSON objects.
-
-    Detects ``{"name": "<func>", "arguments": {...}}`` anywhere in the
-    generated text.  Handles single and (non-overlapping) multiple tool
-    calls.  Text preceding the first tool call is emitted as plain
-    ``content`` deltas.
-    """
-
-    def __init__(self, tools=None, tool_choice="auto"):
-        super().__init__(tools, tool_choice)
-        self._emitted_content_len = 0
-        self._tc_state: List[Dict] = []
-        self._has_tool_calls = False
-
-    # -------------------------------------------------------------- feed
-
-    def feed(
-        self,
-        body: str,
-        current_token_ids: Optional[List[int]] = None,
-        delta_token_ids: Optional[List[int]] = None,
-    ) -> List[Dict]:
-        deltas: List[Dict] = []
-
-        completed = _find_tool_calls(body)
-
-        if not completed:
-            partial = _find_partial_tool_call(body)
-            if not partial:
-                return self._emit_plain_content(body, deltas)
-            all_tcs = [partial]
-        else:
-            all_tcs = completed
-            partial = _find_partial_tool_call(body, completed[-1]["end"])
-            if partial:
-                all_tcs = completed + [partial]
-
-        first_start = all_tcs[0]["start"]
-        if first_start > self._emitted_content_len:
-            content = body[self._emitted_content_len : first_start]
-            self._emitted_content_len = first_start
-            if content:
-                deltas.append({"content": content})
-
-        for i, tc in enumerate(all_tcs):
-            if i >= len(self._tc_state):
-                self._tc_state.append(
-                    {
-                        "id": f"call_{uuid.uuid4().hex[:12]}",
-                        "name_emitted": False,
-                        "args_emitted_len": 0,
-                    }
-                )
-                self._has_tool_calls = True
-            st = self._tc_state[i]
-
-            if not st["name_emitted"]:
-                st["name_emitted"] = True
-                deltas.append(
-                    {
-                        "tool_calls": [
-                            {
-                                "index": i,
-                                "id": st["id"],
-                                "type": "function",
-                                "function": {"name": tc["name"], "arguments": ""},
-                            }
-                        ]
-                    }
-                )
-
-            new_args = tc["args"]
-            if len(new_args) > st["args_emitted_len"]:
-                diff = new_args[st["args_emitted_len"] :]
-                st["args_emitted_len"] = len(new_args)
-                deltas.append(
-                    {
-                        "tool_calls": [
-                            {
-                                "index": i,
-                                "function": {"arguments": diff},
-                            }
-                        ]
-                    }
-                )
-
-        return deltas
-
-    def _emit_plain_content(self, body: str, deltas: List[Dict]) -> List[Dict]:
-        new_content = body[self._emitted_content_len :]
-        if new_content:
-            self._emitted_content_len = len(body)
-            deltas.append({"content": new_content})
-        return deltas
-
-    # -------------------------------------------------------- complete
-
-    def parse_complete(self, body: str) -> Optional[Dict]:
-        completed = _find_tool_calls(body)
-        if not completed:
-            return None
-
-        content = body[: completed[0]["start"]].strip() or None
-        tool_calls = []
-        for i, tc in enumerate(completed):
-            tool_calls.append(
-                {
-                    "id": f"call_{uuid.uuid4().hex[:12]}",
-                    "type": "function",
-                    "function": {
-                        "name": tc["name"],
-                        "arguments": tc["args"],
-                    },
-                }
-            )
-        return {"content": content, "tool_calls": tool_calls}
-
-    @property
-    def has_tool_calls(self) -> bool:
-        return self._has_tool_calls
@@ -2,12 +2,8 @@

 from astrai.inference.core.cache import (
    Allocator,
-    CacheView,
-    ContiguousCache,
-    ContiguousCacheView,
    KVCache,
-    PageCache,
-    PageCacheView,
+    KvcacheView,
    PagePool,
    PrefixCache,
    Storage,
@@ -20,12 +16,8 @@ from astrai.inference.core.task import STOP, Task, TaskManager, TaskStatus

 __all__ = [
    "Allocator",
-    "CacheView",
    "KVCache",
-    "ContiguousCache",
-    "ContiguousCacheView",
-    "PageCache",
-    "PageCacheView",
+    "KvcacheView",
    "PagePool",
    "PrefixCache",
    "Storage",
@@ -1,5 +1,4 @@
 import threading
-from abc import ABC, abstractmethod
 from collections import OrderedDict
 from typing import Callable, Dict, List, Optional, Tuple

@@ -43,7 +42,7 @@ class Allocator:
                return idx
            return -1

-    def free(self, idx: int, keep_cached: bool = False):
+    def free(self, idx: int, keep_cached: bool = False) -> None:
        with self._lock:
            self._refs[idx] -= 1
            if self._refs[idx] == 0:
@@ -52,7 +51,7 @@ class Allocator:
                else:
                    self._free_mask |= 1 << idx

-    def inc_ref(self, idx: int):
+    def inc_ref(self, idx: int) -> None:
        with self._lock:
            self._refs[idx] += 1
            self._lru.pop(idx, None)
@@ -61,10 +60,9 @@ class Allocator:
        with self._lock:
            return self._refs[idx]

-    def touch(self, idx: int):
+    def touch(self, idx: int) -> None:
        with self._lock:
-            if idx in self._lru:
-                self._lru.move_to_end(idx)
+            self._lru.move_to_end(idx)


 class PrefixCache:
@@ -76,7 +74,7 @@ class PrefixCache:
        self._hash_to_page: Dict[int, int] = {}
        self._lock = threading.Lock()

-    def evict(self, idx: int):
+    def evict(self, idx: int) -> None:
        with self._lock:
            h = self._page_to_hash.pop(idx, None)
            if h is not None:
@@ -98,7 +96,9 @@ class PrefixCache:
                hits.append(p)
            return hits

-    def record(self, page_idx: int, token_ids: List[int], logical_page_idx: int):
+    def record(
+        self, page_idx: int, token_ids: List[int], logical_page_idx: int
+    ) -> None:
        with self._lock:
            h = page_hash(token_ids, logical_page_idx, self._page_size)
            old_h = self._page_to_hash.pop(page_idx, None)
@@ -127,13 +127,13 @@ class PagePool:
    def alloc(self) -> int:
        return self._alloc.alloc()

-    def free(self, idx: int):
+    def free(self, idx: int) -> None:
        keep = self._prefix.has_page(idx)
        self._alloc.free(idx, keep_cached=keep)
        if not keep:
            self._prefix.evict(idx)

-    def inc_ref(self, idx: int):
+    def inc_ref(self, idx: int) -> None:
        self._alloc.inc_ref(idx)

    def lookup(self, token_ids: List[int]) -> List[int]:
@@ -142,7 +142,9 @@ class PagePool:
            self._alloc.touch(p)
        return hits

-    def record(self, page_idx: int, token_ids: List[int], logical_page_idx: int):
+    def record(
+        self, page_idx: int, token_ids: List[int], logical_page_idx: int
+    ) -> None:
        self._prefix.record(page_idx, token_ids, logical_page_idx)


@@ -155,7 +157,7 @@ class TaskTable:
        self._cached: Dict[str, int] = {}
        self._lock = threading.Lock()

-    def set(self, task_id: str, page_table: List[int], cached: int):
+    def set(self, task_id: str, page_table: List[int], cached: int) -> None:
        with self._lock:
            self._pages[task_id] = page_table
            self._cached[task_id] = cached
@@ -218,7 +220,7 @@ class Storage:
        start_pos: int,
        k: Tensor,
        v: Tensor,
-    ):
+    ) -> None:
        seq_len = k.size(1)
        if seq_len == 0:
            return
@@ -276,46 +278,7 @@ class Storage:
        return k, v


-class CacheView(ABC):
-    """Abstract view passed to attention layers for KV-cache I/O."""
-
-    @abstractmethod
-    def write(self, layer_id: int, k: Tensor, v: Tensor): ...
-
-    @abstractmethod
-    def gather(self, layer_id: int) -> Tuple[Tensor, Tensor]: ...
-
-
-class KVCache(ABC):
-    """Abstract KV-cache facade for scheduler/executor."""
-
-    @abstractmethod
-    def task_alloc(self, task_id: str, prompt_ids: List[int]) -> bool: ...
-
-    @abstractmethod
-    def task_free(self, task_id: str): ...
-
-    @abstractmethod
-    def task_extend(self, task_id: str, pos: int) -> bool: ...
-
-    @abstractmethod
-    def bind_tasks(
-        self,
-        task_ids: List[str],
-        total_len: int,
-        device: torch.device,
-        write_positions: Optional[Tensor] = None,
-    ) -> CacheView: ...
-
-    def task_cached(self, task_id: str) -> int:
-        return 0
-
-    def task_record_hashes(
-        self, task_id: str, prompt_ids: List[int], start_logical_page: int = 0
-    ): ...
-
-
-class PageCacheView(CacheView):
+class KvcacheView:
    """Bundles Storage + page_table + total_len for attention layers."""

    def __init__(self, storage: Storage, page_table: Tensor, total_len: int = 0):
@@ -323,7 +286,7 @@ class PageCacheView(CacheView):
        self._page_table = page_table
        self._total_len = total_len

-    def write(self, layer_id: int, k: Tensor, v: Tensor):
+    def write(self, layer_id: int, k: Tensor, v: Tensor) -> None:
        start_pos = self._total_len - k.size(1)
        self._storage.write(layer_id, self._page_table, start_pos, k, v)

@@ -331,8 +294,8 @@ class PageCacheView(CacheView):
        return self._storage.gather(layer_id, self._page_table, self._total_len)


-class PageCache(KVCache):
-    """Paged KV-cache with prefix sharing."""
+class KVCache:
+    """Facade: page management + KV-cache I/O for continuous batching."""

    def __init__(
        self,
@@ -376,7 +339,7 @@ class PageCache(KVCache):
        self._table.set(task_id, hits + new_pages, cached)
        return True

-    def task_free(self, task_id: str):
+    def task_free(self, task_id: str) -> None:
        page_table, _ = self._table.pop(task_id)
        for idx in page_table:
            self._pool.free(idx)
@@ -396,130 +359,14 @@ class PageCache(KVCache):

    def task_record_hashes(
        self, task_id: str, prompt_ids: List[int], start_logical_page: int = 0
-    ):
+    ) -> None:
        page_table = self._table.get(task_id)
        full_pages = len(prompt_ids) // self.page_size
        for i in range(start_logical_page, full_pages):
            self._pool.record(page_table[i], prompt_ids, i)

-    def bind_tasks(
-        self,
-        task_ids: List[str],
-        total_len: int,
-        device: torch.device,
-        write_positions: Optional[Tensor] = None,
-    ) -> PageCacheView:
-        page_table = self._table.table_tensor(task_ids, device)
-        return PageCacheView(self._storage, page_table, total_len)
+    def make_table_tensor(self, task_ids: List[str], device: torch.device) -> Tensor:
+        return self._table.table_tensor(task_ids, device)

-
-class ContiguousCacheView(CacheView):
-    """Contiguous KV-cache view for attention layers."""
-
-    def __init__(
-        self,
-        cache: "ContiguousCache",
-        batch_indices: Tensor,
-        total_len: int = 0,
-        write_positions: Optional[Tensor] = None,
-    ):
-        self._cache = cache
-        self._batch_indices = batch_indices
-        self._total_len = total_len
-        self._write_positions = write_positions
-
-    def write(self, layer_id: int, k: Tensor, v: Tensor):
-        seq_len = k.size(1)
-        indices = self._batch_indices
-        if self._write_positions is not None and seq_len == 1:
-            pos = self._write_positions
-            self._cache.k[layer_id, indices, pos] = k.squeeze(1)
-            self._cache.v[layer_id, indices, pos] = v.squeeze(1)
-        else:
-            start_pos = self._total_len - seq_len
-            self._cache.k[layer_id, indices, start_pos : start_pos + seq_len] = k
-            self._cache.v[layer_id, indices, start_pos : start_pos + seq_len] = v
-
-    def gather(self, layer_id: int) -> Tuple[Tensor, Tensor]:
-        max_len = self._total_len
-        indices = self._batch_indices
-        k = self._cache.k[layer_id, indices, :max_len]
-        v = self._cache.v[layer_id, indices, :max_len]
-        return k, v
-
-
-class ContiguousCache(KVCache):
-    """Contiguous per-slot KV cache (default implementation)."""
-
-    def __init__(
-        self,
-        n_layers: int,
-        max_batch_size: int,
-        max_seq_len: int,
-        n_kv_heads: int,
-        head_dim: int,
-        device: torch.device,
-        dtype: torch.dtype,
-    ):
-        self.max_seq_len = max_seq_len
-        self.k = torch.zeros(
-            n_layers,
-            max_batch_size,
-            max_seq_len,
-            n_kv_heads,
-            head_dim,
-            device=device,
-            dtype=dtype,
-        )
-        self.v = torch.zeros(
-            n_layers,
-            max_batch_size,
-            max_seq_len,
-            n_kv_heads,
-            head_dim,
-            device=device,
-            dtype=dtype,
-        )
-        self._slot_len: Dict[int, int] = {}
-        self._task_slot: Dict[str, int] = {}
-        self._free_slots = list(range(max_batch_size))
-        self._device = device
-
-    def task_alloc(self, task_id: str, prompt_ids: List[int]) -> bool:
-        if not self._free_slots:
-            return False
-        slot = self._free_slots.pop(0)
-        self._task_slot[task_id] = slot
-        self._slot_len[slot] = 0
-        return True
-
-    def task_free(self, task_id: str):
-        slot = self._task_slot.pop(task_id, None)
-        if slot is not None:
-            self._slot_len.pop(slot, None)
-            self._free_slots.append(slot)
-
-    def task_extend(self, task_id: str, pos: int) -> bool:
-        return pos < self.max_seq_len
-
-    def task_cached(self, task_id: str) -> int:
-        slot = self._task_slot.get(task_id)
-        if slot is None:
-            return 0
-        return self._slot_len.get(slot, 0)
-
-    def bind_tasks(
-        self,
-        task_ids: List[str],
-        total_len: int,
-        device: torch.device,
-        write_positions: Optional[Tensor] = None,
-    ) -> ContiguousCacheView:
-        slots = [self._task_slot[tid] for tid in task_ids]
-        batch_indices = torch.tensor(slots, dtype=torch.long, device=device)
-        for slot in slots:
-            if total_len > self._slot_len.get(slot, 0):
-                self._slot_len[slot] = total_len
-        return ContiguousCacheView(
-            self, batch_indices, total_len, write_positions=write_positions
-        )
+    def bind(self, page_table: Tensor, total_len: int = 0) -> KvcacheView:
+        return KvcacheView(self._storage, page_table, total_len)
@@ -19,17 +19,19 @@ class Executor:
        self,
        model: AutoModel,
        tokenizer: AutoTokenizer,
-        kv_cache: KVCache,
+        page_cache: KVCache,
        device: Optional[str] = None,
        dtype: Optional[torch.dtype] = None,
    ):
        self.model = model
        self.tokenizer = tokenizer
-        self.kv_cache = kv_cache
+        self.page_cache = page_cache
        self.device = device or next(model.parameters()).device
        self.dtype = dtype or next(model.parameters()).dtype

-    def execute_prefill(self, tasks: List[Task], prompt_len: int, start_pos: int = 0):
+    def execute_prefill(
+        self, tasks: List[Task], prompt_len: int, start_pos: int = 0
+    ) -> None:
        if start_pos >= prompt_len:
            return

@@ -43,40 +45,20 @@ class Executor:
        )

        task_ids = [t.task_id for t in tasks]
-        position_ids = (
-            torch.arange(start_pos, prompt_len, dtype=torch.long, device=self.device)
-            .unsqueeze(0)
-            .expand(batch_sz, -1)
-        )
-        input_mask = position_ids.unsqueeze(-1) >= torch.arange(
-            prompt_len, device=self.device
-        )
+        page_tables = self.page_cache.make_table_tensor(task_ids, self.device)

        with torch.inference_mode():
            self.model(
                input_ids,
-                input_mask=input_mask,
-                position_ids=position_ids,
-                paged_cache=self.kv_cache.bind_tasks(task_ids, prompt_len, self.device),
+                position_ids=torch.arange(
+                    start_pos, prompt_len, dtype=torch.long, device=self.device
+                )
+                .unsqueeze(0)
+                .expand(batch_sz, -1),
+                paged_cache=self.page_cache.bind(page_tables, total_len=prompt_len),
            )

-    def execute_decode(
-        self, tasks: List[Task], return_logprobs: bool = False
-    ) -> List[int]:
-        """Decode next token for each task.
-
-        Args:
-            return_logprobs: When ``True``, also record (and return)
-                the log-probability of each sampled token under the
-                post-strategy sampling distribution.  The logprob is
-                appended to ``task.output_logprobs`` and the return
-                list becomes ``List[Tuple[int, float]]``.
-
-        Returns:
-            ``List[int]`` of sampled token IDs, or
-            ``List[Tuple[int, float]]`` of ``(token_id, logprob)`` when
-            ``return_logprobs`` is ``True``.
-        """
+    def execute_decode(self, tasks: List[Task]) -> List[int]:
        if not tasks:
            return []

@@ -89,78 +71,26 @@ class Executor:
        position_ids = torch.tensor(
            [t.next_pos for t in tasks], dtype=torch.long, device=self.device
        )
-        total_len = max(t.next_pos for t in tasks) + 1
-        input_mask = position_ids[:, None, None] >= torch.arange(
-            total_len, device=self.device
-        )
+        total_len = position_ids.max().item() + 1

        task_ids = [t.task_id for t in tasks]
+        page_tables = self.page_cache.make_table_tensor(task_ids, self.device)

        temperatures = torch.tensor([t.temperature for t in tasks], device=self.device)
        top_ks = torch.tensor([t.top_k for t in tasks], device=self.device)
        top_ps = torch.tensor([t.top_p for t in tasks], device=self.device)
-        freq_penalties = torch.tensor(
-            [t.frequency_penalty for t in tasks], device=self.device
-        )
-
-        history_lists = []
-        history_lens = []
-        for t in tasks:
-            window = t.rep_window
-            prompt_part = t.prompt_ids[-window:]
-            ids = prompt_part + t.output_ids
-            history_lists.append(ids)
-            history_lens.append(len(ids))
-
-        max_len = max(history_lens) if history_lens else 0
-        padded_ids = torch.zeros(
-            len(tasks), max_len, dtype=torch.long, device=self.device
-        )
-        padded_mask = torch.zeros(
-            len(tasks), max_len, dtype=torch.bool, device=self.device
-        )
-        for i, h in enumerate(history_lists):
-            L = history_lens[i]
-            padded_ids[i, :L] = torch.as_tensor(h, dtype=torch.long, device=self.device)
-            padded_mask[i, :L] = True

        with torch.inference_mode():
            outputs = self.model(
                input_ids.unsqueeze(1),
-                input_mask=input_mask,
-                paged_cache=self.kv_cache.bind_tasks(
-                    task_ids,
-                    total_len,
-                    self.device,
-                    write_positions=position_ids,
-                ),
+                paged_cache=self.page_cache.bind(page_tables, total_len=total_len),
                position_ids=position_ids.unsqueeze(1),
            )
            logits = outputs["logits"][:, -1, :]

-        if return_logprobs:
-            tokens, logprobs = sample(
-                logits,
-                temperature=temperatures,
-                top_k=top_ks,
-                top_p=top_ps,
-                frequency_penalty=freq_penalties,
-                input_ids=padded_ids,
-                input_mask=padded_mask,
-                return_logprobs=True,
-            )
-            tokens_list = tokens.tolist()
-            logprobs_list = logprobs.tolist()
-            for t, lp in zip(tasks, logprobs_list):
-                t.output_logprobs.append(float(lp))
-            return list(zip(tokens_list, logprobs_list))
-
        return sample(
            logits,
            temperature=temperatures,
            top_k=top_ks,
            top_p=top_ps,
-            frequency_penalty=freq_penalties,
-            input_ids=padded_ids,
-            input_mask=padded_mask,
        ).tolist()
@@ -1,11 +1,10 @@
 import logging
 import threading
-import uuid
 from typing import Any, Dict, List, Optional, Tuple

 import torch

-from astrai.inference.core.cache import ContiguousCache, KVCache
+from astrai.inference.core.cache import KVCache
 from astrai.inference.core.executor import Executor
 from astrai.inference.core.task import STOP, Task, TaskManager, TaskStatus
 from astrai.model.automodel import AutoModel
@@ -15,7 +14,7 @@ logger = logging.getLogger(__name__)


 class InferenceScheduler:
-    """Continuous batching loop: cleanup -> refill -> prefill -> decode (all groups)."""
+    """Four-phase continuous batching loop: cleanup -> refill -> prefill -> decode."""

    def __init__(
        self,
@@ -24,38 +23,37 @@ class InferenceScheduler:
        max_batch_size: int = 16,
        max_seq_len: Optional[int] = None,
        max_prompt_len: int = 2048,
+        page_size: int = 64,
        device: Optional[str] = None,
        dtype: Optional[torch.dtype] = None,
-        cache: Optional[KVCache] = None,
    ):
        config = model.config

        if max_seq_len is not None:
            self.max_seq_len = max_seq_len
-        elif config.max_position_embeddings is not None:
-            self.max_seq_len = config.max_position_embeddings
+        elif config.max_len is not None:
+            self.max_seq_len = config.max_len
        else:
            raise ValueError(
                "max_seq_len must be provided either as argument "
-                "or in model config (config.max_position_embeddings)"
+                "or in model config (config.max_len)"
            )
        self.device = device or next(model.parameters()).device
        self.dtype = dtype or next(model.parameters()).dtype

-        head_dim = config.hidden_size // config.num_attention_heads
+        n_pages = (
+            max_batch_size * (self.max_seq_len + page_size) + page_size - 1
+        ) // page_size

-        if cache is not None:
-            self._cache = cache
-        else:
-            self._cache = ContiguousCache(
-                config.num_hidden_layers,
-                max_batch_size,
-                self.max_seq_len,
-                config.num_key_value_heads,
-                head_dim,
-                self.device,
-                self.dtype,
-            )
+        self._page_cache = KVCache(
+            config.n_layers,
+            n_pages,
+            page_size,
+            config.n_kv_heads,
+            config.dim // config.n_heads,
+            self.device,
+            self.dtype,
+        )

        self._task_mgr = TaskManager(
            tokenizer=tokenizer,
@@ -67,32 +65,30 @@ class InferenceScheduler:
        self._executor = Executor(
            model=model,
            tokenizer=tokenizer,
-            kv_cache=self._cache,
+            page_cache=self._page_cache,
            device=self.device,
            dtype=self.dtype,
        )

-        self._stop_event = threading.Event()
-        self._loop_thread: Optional[threading.Thread] = None
+        self._running = False

    def add_task(self, prompt: str, **kwargs) -> str:
        return self._task_mgr.add_task(prompt, **kwargs)

-    def remove_task(self, task_id: str):
+    def remove_task(self, task_id: str) -> None:
        for task in self._task_mgr.remove_task(task_id):
-            self._cache.task_free(task.task_id)
+            self._page_cache.task_free(task.task_id)

    def get_stats(self) -> Dict[str, Any]:
        return self._task_mgr.get_stats()

-    def _run_generation_loop(self):
+    def _run_generation_loop(self) -> None:
        stop_ids = self._task_mgr.tokenizer.stop_ids
-        cache = self._cache
        try:
-            while not self._stop_event.is_set():
+            while self._running:
                finished = self._task_mgr.remove_finished_tasks(stop_ids)
                for task in finished:
-                    cache.task_free(task.task_id)
+                    self._page_cache.task_free(task.task_id)

                active = self._task_mgr.get_active_tasks()
                available = self._task_mgr.max_batch_size - len(active)
@@ -100,7 +96,7 @@ class InferenceScheduler:
                    candidates = self._task_mgr.pull_candidates(available)
                    failed = []
                    for task in candidates:
-                        if cache.task_alloc(task.task_id, task.prompt_ids):
+                        if self._page_cache.task_alloc(task.task_id, task.prompt_ids):
                            self._task_mgr.activate(task)
                        else:
                            failed.append(task)
@@ -112,10 +108,7 @@ class InferenceScheduler:
                    continue

                to_prefill = [
-                    t
-                    for t in self._task_mgr.get_active_tasks()
-                    if t.output_tokens == 0
-                    and cache.task_cached(t.task_id) < len(t.prompt_ids)
+                    t for t in self._task_mgr.get_active_tasks() if t.output_tokens == 0
                ]
                if to_prefill:
                    for t in to_prefill:
@@ -125,187 +118,85 @@ class InferenceScheduler:
                    for t in to_prefill:
                        key = (
                            len(t.prompt_ids),
-                            cache.task_cached(t.task_id),
+                            self._page_cache.task_cached(t.task_id),
                        )
                        groups.setdefault(key, []).append(t)

                    for (prompt_len, start_pos), group in groups.items():
                        self._executor.execute_prefill(group, prompt_len, start_pos)
-                        start_logical_page = start_pos // getattr(
-                            cache, "page_size", 64
-                        )
+                        start_logical_page = start_pos // self._page_cache.page_size
                        for t in group:
-                            cache.task_record_hashes(
-                                t.task_id, t.prompt_ids, start_logical_page
+                            self._page_cache.task_record_hashes(
+                                t.task_id,
+                                t.prompt_ids,
+                                start_logical_page=start_logical_page,
                            )

-                decode_tasks = self._task_mgr.get_active_tasks()
+                pos_groups: Dict[int, List[Task]] = {}
+                for t in self._task_mgr.get_active_tasks():
+                    pos_groups.setdefault(t.next_pos, []).append(t)

-                valid: List[Task] = []
-                for t in sorted(decode_tasks, key=lambda t: t.task_id):
-                    if cache.task_extend(t.task_id, t.next_pos):
-                        valid.append(t)
-                    else:
-                        t.status = TaskStatus.ABORTED
-                        self._task_mgr.invoke_callback(t.task_id, STOP)
+                if pos_groups:
+                    best_key = max(pos_groups, key=lambda k: len(pos_groups[k]))
+                    group = sorted(pos_groups[best_key], key=lambda t: t.task_id)

-                if valid:
-                    next_tokens = self._executor.execute_decode(valid)
+                    valid: List[Task] = []
+                    for t in group:
+                        if self._page_cache.task_extend(t.task_id, t.next_pos):
+                            valid.append(t)
+                        else:
+                            t.status = TaskStatus.ABORTED
+                            if t.stream_callback:
+                                t.stream_callback(STOP)

-                    for t, ntok in zip(valid, next_tokens):
-                        t.output_ids.append(ntok)
-                        t.output_tokens += 1
-                        new_text = t.decode_new_token(self._task_mgr.tokenizer)
-                        if new_text:
-                            self._task_mgr.invoke_callback(t.task_id, new_text)
+                    if valid:
+                        next_tokens = self._executor.execute_decode(valid)

-                    for t in valid:
-                        if t.is_finished(stop_ids):
-                            remaining = t.flush_remaining(self._task_mgr.tokenizer)
-                            if remaining:
-                                self._task_mgr.invoke_callback(t.task_id, remaining)
-                            self._task_mgr.invoke_callback(t.task_id, STOP)
+                        for t, ntok in zip(valid, next_tokens):
+                            t.output_ids.append(ntok)
+                            t.output_tokens += 1
+                            pos = t.input_tokens + t.output_tokens
+                            extend_ok = self._page_cache.task_extend(t.task_id, pos)
+                            if t.stream_callback:
+                                t.stream_callback(
+                                    self._task_mgr.tokenizer.decode([ntok])
+                                )
+                            if not extend_ok:
+                                t.status = TaskStatus.ABORTED
+                                if t.stream_callback:
+                                    t.stream_callback(STOP)
+
+                        for t in valid:
+                            if t.is_finished(stop_ids):
+                                if t.stream_callback:
+                                    t.stream_callback(STOP)

        except Exception as e:
-            self._stop_event.set()
            logger.error(f"Scheduler loop crashed: {e}", exc_info=True)
            for task in self._task_mgr.get_active_tasks():
-                self._task_mgr.invoke_callback(task.task_id, STOP)
-                cache.task_free(task.task_id)
+                if task.stream_callback:
+                    task.stream_callback(STOP)
+                self._page_cache.task_free(task.task_id)
            for task in self._task_mgr.get_waiting_tasks():
-                self._task_mgr.invoke_callback(task.task_id, STOP)
+                if task.stream_callback:
+                    task.stream_callback(STOP)
            self._task_mgr.clear_queues()
+            raise

-    def start(self):
-        if self._loop_thread is not None and self._loop_thread.is_alive():
-            return
-        self._stop_event.clear()
-        t = threading.Thread(target=self._run_generation_loop, daemon=True)
-        t.start()
-        self._loop_thread = t
+    def start(self) -> None:
+        if not self._running:
+            self._running = True
+            t = threading.Thread(target=self._run_generation_loop, daemon=True)
+            t.start()
+            self._loop_thread = t

-    def stop(self):
-        self._stop_event.set()
+    def stop(self) -> None:
+        self._running = False
        self._task_mgr.wake()
-        if self._loop_thread is not None:
+        if hasattr(self, "_loop_thread"):
            self._loop_thread.join(timeout=2.0)
-        self._loop_thread = None
        for task in self._task_mgr.get_active_tasks():
-            self._task_mgr.invoke_callback(task.task_id, STOP)
-            self._cache.task_free(task.task_id)
-        for task in self._task_mgr.get_waiting_tasks():
-            self._task_mgr.invoke_callback(task.task_id, STOP)
-            self._cache.task_free(task.task_id)
+            self._page_cache.task_free(task.task_id)
        self._task_mgr.clear_queues()
        if torch.cuda.is_available():
            torch.cuda.empty_cache()
-
-    def run_batch(
-        self,
-        prompt_ids_list: List[List[int]],
-        *,
-        max_tokens: Optional[int] = None,
-        temperature: float = 1.0,
-        top_p: float = 1.0,
-        top_k: int = 50,
-        frequency_penalty: float = 0.0,
-        rep_window: int = 64,
-        return_logprobs: bool = False,
-    ) -> List[List[int]]:
-        """Synchronous batch generation without the scheduler thread.
-
-        Accepts already-tokenized prompts (no string round-trip) and runs
-        prefill + decode to completion on the calling thread.  Designed for
-        RL rollout, where logprobs of the behaviour policy must be collected
-        alongside generated tokens.
-
-        Args:
-            prompt_ids_list: ``B`` prompts, each a list of token IDs.
-            max_tokens: Maximum tokens to generate per prompt.  ``None``
-                uses ``self.max_seq_len - len(prompt_ids)``.
-            temperature/top_p/top_k/frequency_penalty/rep_window: Sampling
-                parameters (uniform across the batch).
-            return_logprobs: If ``True``, return ``(token_ids, logprobs)``
-                tuples per prompt (logprobs aligned 1-to-1 with token_ids).
-
-        Returns:
-            ``List[List[int]]`` of generated token IDs per prompt, or —
-            when ``return_logprobs`` is ``True`` —
-            ``List[Tuple[List[int], List[float]]]``.
-        """
-        stop_ids = self._task_mgr.tokenizer.stop_ids
-        cache = self._cache
-        seq_cap = self.max_seq_len
-
-        tasks: List[Task] = []
-        for ids in prompt_ids_list:
-            if len(ids) >= seq_cap:
-                tasks.append(None)
-                continue
-            t_max = max_tokens
-            if t_max is None:
-                t_max = seq_cap - len(ids)
-            else:
-                t_max = min(t_max, seq_cap - len(ids))
-            task = Task(
-                task_id=f"batch_{uuid.uuid4().hex[:8]}",
-                prompt_ids=list(ids),
-                max_tokens=t_max,
-                temperature=temperature,
-                top_p=top_p,
-                top_k=top_k,
-                frequency_penalty=frequency_penalty,
-                rep_window=rep_window,
-            )
-            if not cache.task_alloc(task.task_id, task.prompt_ids):
-                tasks.append(None)
-                continue
-            task.input_tokens = len(task.prompt_ids)
-            tasks.append(task)
-
-        try:
-            live = [t for t in tasks if t is not None]
-            prefill_groups: Dict[Tuple[int, int], List[Task]] = {}
-            for t in live:
-                key = (len(t.prompt_ids), cache.task_cached(t.task_id))
-                prefill_groups.setdefault(key, []).append(t)
-            for (prompt_len, start_pos), group in prefill_groups.items():
-                self._executor.execute_prefill(group, prompt_len, start_pos)
-
-            while live:
-                valid: List[Task] = []
-                for t in sorted(live, key=lambda x: x.task_id):
-                    if cache.task_extend(t.task_id, t.next_pos):
-                        valid.append(t)
-                    else:
-                        t.status = TaskStatus.ABORTED
-                if not valid:
-                    break
-
-                step_out = self._executor.execute_decode(
-                    valid, return_logprobs=return_logprobs
-                )
-                if return_logprobs:
-                    for t, (ntok, _lp) in zip(valid, step_out):
-                        t.output_ids.append(ntok)
-                        t.output_tokens += 1
-                else:
-                    for t, ntok in zip(valid, step_out):
-                        t.output_ids.append(ntok)
-                        t.output_tokens += 1
-
-                live = [t for t in valid if not t.is_finished(stop_ids)]
-        finally:
-            for t in tasks:
-                if t is not None:
-                    cache.task_free(t.task_id)
-
-        results: List[Any] = []
-        for t in tasks:
-            if t is None:
-                results.append(([], []) if return_logprobs else [])
-            elif return_logprobs:
-                results.append((list(t.output_ids), list(t.output_logprobs)))
-            else:
-                results.append(list(t.output_ids))
-        return results
@@ -13,40 +13,6 @@ logger = logging.getLogger(__name__)
 STOP = object()


-class StreamDecoder:
-    """Incremental decoder for byte-level BPE streaming.
-
-    Byte-level BPE may split a single Unicode character (e.g. em-dash,
-    smart quotes) across multiple tokens. Decoding such a token in
-    isolation produces U+FFFD (replacement char). This decoder
-    accumulates token IDs and only emits text once the trailing
-    characters are complete, buffering incomplete multi-byte sequences
-    until the next token arrives.
-    """
-
-    __slots__ = ("_tokenizer", "_ids", "_emitted")
-
-    def __init__(self, tokenizer: AutoTokenizer):
-        self._tokenizer = tokenizer
-        self._ids: List[int] = []
-        self._emitted: str = ""
-
-    def push(self, token_id: int) -> str:
-        """Append a token ID and return newly completed text.
-
-        Returns "" while a multi-byte character is still incomplete.
-        """
-        self._ids.append(token_id)
-        full = self._tokenizer.decode(self._ids, skip_special_tokens=True)
-        if full.endswith("\ufffd"):
-            return ""
-        if len(full) > len(self._emitted):
-            diff = full[len(self._emitted) :]
-            self._emitted = full
-            return diff
-        return ""
-
-
 class TaskStatus(Enum):
    """Task lifecycle states."""

@@ -67,8 +33,7 @@ class Task:
        temperature: float = 1.0,
        top_p: float = 1.0,
        top_k: int = 50,
-        frequency_penalty: float = 0.0,
-        rep_window: int = 64,
+        stream_callback: Optional[Callable[[str], None]] = None,
    ):
        self.task_id = task_id
        self.prompt_ids = prompt_ids
@@ -76,44 +41,14 @@ class Task:
        self.temperature = temperature
        self.top_p = top_p
        self.top_k = top_k
-        self.frequency_penalty = frequency_penalty
-        self.rep_window = rep_window

        self.status = TaskStatus.PENDING
        self.output_ids: List[int] = []
-        self.output_logprobs: List[float] = []
        self.input_tokens: int = 0
        self.output_tokens: int = 0
        self.arrival_time = time.time()
        self.finish_time: Optional[float] = None
-        self._decoder: Optional[StreamDecoder] = None
-
-    def decode_new_token(self, tokenizer: AutoTokenizer) -> str:
-        """Decode the last appended output token, buffering incomplete
-        multi-byte sequences across calls.
-
-        Lazily creates a :class:`StreamDecoder` on first use.
-        """
-        if self._decoder is None:
-            self._decoder = StreamDecoder(tokenizer)
-        return self._decoder.push(self.output_ids[-1])
-
-    def flush_remaining(self, tokenizer: AutoTokenizer) -> str:
-        """Emit any text still buffered in the decoder.
-
-        Called when generation terminates (max_tokens reached, stop
-        sequence, or external removal) to avoid dropping a final
-        incomplete-looking fragment that is actually complete when
-        adjacent to the stop token.
-        """
-        if self._decoder is None or not self.output_ids:
-            return ""
-        full = tokenizer.decode(self.output_ids, skip_special_tokens=True)
-        if len(full) > len(self._decoder._emitted):
-            diff = full[len(self._decoder._emitted) :]
-            self._decoder._emitted = full
-            return diff
-        return ""
+        self.stream_callback = stream_callback

    @property
    def next_pos(self) -> int:
@@ -144,7 +79,6 @@ class TaskManager:

        self.waiting_queue: Deque[Task] = deque()
        self.active_tasks: List[Task] = []
-        self._callbacks: Dict[str, Callable[[str], None]] = {}

        self._task_event = threading.Event()
        self._lock = threading.Lock()
@@ -159,8 +93,6 @@ class TaskManager:
        temperature: float = 1.0,
        top_p: float = 1.0,
        top_k: int = 50,
-        frequency_penalty: float = 0.0,
-        rep_window: int = 64,
        stream_callback: Optional[Callable[[str], None]] = None,
    ) -> str:
        task_id = f"task_{int(time.time())}_{uuid.uuid4().hex[:8]}"
@@ -185,15 +117,12 @@ class TaskManager:
            temperature=temperature,
            top_p=top_p,
            top_k=top_k,
-            frequency_penalty=frequency_penalty,
-            rep_window=rep_window,
+            stream_callback=stream_callback,
        )

        with self._lock:
            self.waiting_queue.append(task)
            self._total_tasks += 1
-            if stream_callback:
-                self._callbacks[task_id] = stream_callback

        self._task_event.set()
        return task_id
@@ -205,14 +134,8 @@ class TaskManager:
                t for t in self.waiting_queue if t.task_id != task_id
            )
            self.active_tasks = [t for t in self.active_tasks if t.task_id != task_id]
-            self._callbacks.pop(task_id, None)
        return removed_active

-    def invoke_callback(self, task_id: str, token: str):
-        cb = self._callbacks.get(task_id)
-        if cb:
-            cb(token)
-
    def get_stats(self) -> Dict[str, Any]:
        return {
            "total_tasks": self._total_tasks,
@@ -249,12 +172,12 @@ class TaskManager:
                to_add.append(self.waiting_queue.popleft())
        return to_add

-    def activate(self, task: Task):
+    def activate(self, task: Task) -> None:
        task.status = TaskStatus.RUNNING
        with self._lock:
            self.active_tasks.append(task)

-    def return_to_waiting(self, tasks: List[Task]):
+    def return_to_waiting(self, tasks: List[Task]) -> None:
        with self._lock:
            for task in reversed(tasks):
                self.waiting_queue.appendleft(task)
@@ -262,11 +185,8 @@ class TaskManager:
    def has_work(self) -> bool:
        return bool(self.active_tasks or self.waiting_queue)

-    def wait_for_tasks(self, timeout: float = 1.0):
-        with self._lock:
-            if self.waiting_queue or self.active_tasks:
-                return
-            self._task_event.clear()
+    def wait_for_tasks(self, timeout: float = 1.0) -> None:
+        self._task_event.clear()
        self._task_event.wait(timeout=timeout)

    def get_active_tasks(self) -> List[Task]:
@@ -277,11 +197,10 @@ class TaskManager:
        with self._lock:
            return list(self.waiting_queue)

-    def clear_queues(self):
+    def clear_queues(self) -> None:
        with self._lock:
            self.waiting_queue.clear()
            self.active_tasks.clear()
-            self._callbacks.clear()

-    def wake(self):
+    def wake(self) -> None:
        self._task_event.set()
@@ -8,12 +8,22 @@ from typing import Any, AsyncGenerator, Dict, Generator, List, Optional, Tuple,
 import torch
 import torch.nn as nn

-from astrai.inference.core.cache import KVCache
 from astrai.inference.core.scheduler import InferenceScheduler
 from astrai.inference.core.task import STOP
 from astrai.tokenize import AutoTokenizer


+def _validate_sampling_params(
+    top_k: int, top_p: float, temperature: float, max_tokens: Optional[int] = None
+):
+    if not (isinstance(top_k, int) and top_k >= 0):
+        raise ValueError("top_k must be a non-negative integer")
+    if not (0.0 <= top_p <= 1.0):
+        raise ValueError("top_p must be a float between 0.0 and 1.0")
+    if not (isinstance(temperature, (int, float)) and temperature >= 0):
+        raise ValueError("temperature must be a non-negative number")
+
+
 class GenerateResult:
    """Thread-safe token accumulator for streaming and non-streaming modes."""

@@ -49,7 +59,7 @@ class GenerateResult:
    def wait(self, timeout: Optional[float] = None) -> bool:
        return self._event.wait(timeout=timeout)

-    def wait_completion(self, timeout: float = 300.0):
+    def wait_completion(self, timeout: float = 300.0) -> None:
        with self._cond:
            if not self._cond.wait_for(
                lambda: self._completed >= self._total, timeout=timeout
@@ -74,31 +84,15 @@ class GenerationRequest:
        top_p: float = 1.0,
        temperature: float = 1.0,
        max_tokens: Optional[int] = None,
-        frequency_penalty: float = 0.0,
-        rep_window: int = 64,
        stream: bool = False,
    ):
-        if not (isinstance(top_k, int) and top_k >= 0):
-            raise ValueError("top_k must be a non-negative integer")
-        if not (0.0 <= top_p <= 1.0):
-            raise ValueError("top_p must be a float between 0.0 and 1.0")
-        if not (isinstance(temperature, (int, float)) and temperature >= 0):
-            raise ValueError("temperature must be a non-negative number")
-        if not (
-            isinstance(frequency_penalty, (int, float))
-            and -2.0 <= frequency_penalty <= 2.0
-        ):
-            raise ValueError("frequency_penalty must be between -2.0 and 2.0")
-        if not (isinstance(rep_window, int) and rep_window > 0):
-            raise ValueError("rep_window must be a positive integer")
+        _validate_sampling_params(top_k, top_p, temperature, max_tokens)

        self.messages = messages
        self.top_k = top_k
        self.top_p = top_p
        self.temperature = temperature
        self.max_tokens = max_tokens
-        self.frequency_penalty = frequency_penalty
-        self.rep_window = rep_window
        self.stream = stream


@@ -113,7 +107,6 @@ class InferenceEngine:
        max_seq_len: Optional[int] = None,
        max_prompt_len: int = 2048,
        page_size: int = 128,
-        cache: Optional[KVCache] = None,
    ):
        self.model = model
        self.tokenizer = tokenizer
@@ -123,7 +116,7 @@ class InferenceEngine:
            max_batch_size=max_batch_size,
            max_seq_len=max_seq_len,
            max_prompt_len=max_prompt_len,
-            cache=cache,
+            page_size=page_size,
        )

        self.scheduler.start()
@@ -143,33 +136,18 @@ class InferenceEngine:
        temperature: float = 1.0,
        top_p: float = 1.0,
        top_k: int = 50,
-        frequency_penalty: float = 0.0,
-        rep_window: int = 64,
    ) -> Union[Generator, str, List[str]]:
+        _validate_sampling_params(top_k, top_p, temperature, max_tokens)
        is_batch = isinstance(prompt, list)
        prompts = prompt if is_batch else [prompt]

        if stream:
            return self._generate_streaming(
-                prompts,
-                is_batch,
-                max_tokens,
-                temperature,
-                top_p,
-                top_k,
-                frequency_penalty,
-                rep_window,
+                prompts, is_batch, max_tokens, temperature, top_p, top_k
            )
        else:
            return self._generate_non_streaming(
-                prompts,
-                is_batch,
-                max_tokens,
-                temperature,
-                top_p,
-                top_k,
-                frequency_penalty,
-                rep_window,
+                prompts, is_batch, max_tokens, temperature, top_p, top_k
            )

    def generate_async(
@@ -179,18 +157,10 @@ class InferenceEngine:
        temperature: float = 1.0,
        top_p: float = 1.0,
        top_k: int = 50,
-        frequency_penalty: float = 0.0,
-        rep_window: int = 64,
    ) -> AsyncGenerator[str, None]:
+        _validate_sampling_params(top_k, top_p, temperature, max_tokens)
        sync_gen = self._generate_streaming(
-            [prompt],
-            False,
-            max_tokens,
-            temperature,
-            top_p,
-            top_k,
-            frequency_penalty,
-            rep_window,
+            [prompt], False, max_tokens, temperature, top_p, top_k
        )

        async def _agen():
@@ -221,8 +191,6 @@ class InferenceEngine:
            temperature=request.temperature,
            top_p=request.top_p,
            top_k=request.top_k,
-            frequency_penalty=request.frequency_penalty,
-            rep_window=request.rep_window,
        )

    def _submit_tasks(
@@ -232,8 +200,6 @@ class InferenceEngine:
        temperature: float,
        top_p: float,
        top_k: int,
-        frequency_penalty: float,
-        rep_window: int,
    ) -> Tuple[GenerateResult, List[str]]:
        n = len(prompts)
        result = GenerateResult(count=n)
@@ -246,8 +212,6 @@ class InferenceEngine:
                temperature=temperature,
                top_p=top_p,
                top_k=top_k,
-                frequency_penalty=frequency_penalty,
-                rep_window=rep_window,
                stream_callback=cb,
            )
            task_ids.append(task_id)
@@ -268,17 +232,9 @@ class InferenceEngine:
        temperature: float,
        top_p: float,
        top_k: int,
-        frequency_penalty: float,
-        rep_window: int,
    ) -> Generator:
        result, task_ids = self._submit_tasks(
-            prompts,
-            max_tokens,
-            temperature,
-            top_p,
-            top_k,
-            frequency_penalty,
-            rep_window,
+            prompts, max_tokens, temperature, top_p, top_k
        )
        n = len(prompts)
        remaining = n
@@ -312,17 +268,9 @@ class InferenceEngine:
        temperature: float,
        top_p: float,
        top_k: int,
-        frequency_penalty: float,
-        rep_window: int,
    ) -> Union[str, List[str]]:
        result, task_ids = self._submit_tasks(
-            prompts,
-            max_tokens,
-            temperature,
-            top_p,
-            top_k,
-            frequency_penalty,
-            rep_window,
+            prompts, max_tokens, temperature, top_p, top_k
        )

        try:
@@ -341,7 +289,7 @@ class InferenceEngine:
    def get_stats(self) -> Dict[str, Any]:
        return self.scheduler.get_stats()

-    def shutdown(self):
+    def shutdown(self) -> None:
        self.scheduler.stop()
        if torch.cuda.is_available():
            torch.cuda.empty_cache()
@@ -1,15 +1,15 @@
 """Composable sampling strategies for logit transformation.

 Implements the Strategy pattern: each sampling technique
-(temperature, top-k, top-p, frequency penalty) is a pluggable
-strategy that can be composed into a pipeline.
+(temperature, top-k, top-p) is a pluggable strategy that
+can be composed into a pipeline.

 All strategies accept both scalar and per-sample tensor
 parameters, so a single pipeline works for any batch size.
 """

 from abc import ABC, abstractmethod
-from typing import List, Optional, Union
+from typing import List, Union

 import torch
 from torch import Tensor
@@ -19,28 +19,16 @@ class BaseSamplingStrategy(ABC):
    """Abstract base for a logit transformation strategy."""

    @abstractmethod
-    def apply(
-        self,
-        logits: Tensor,
-        filter_value: float = -float("inf"),
-        input_ids: Optional[Tensor] = None,
-        input_mask: Optional[Tensor] = None,
-    ) -> Tensor:
+    def apply(self, logits: Tensor, filter_value: float = -float("inf")) -> Tensor:
        """Applies the strategy to logits.

        Args:
            logits: Raw logits tensor (batch, vocab_size).
            filter_value: Value assigned to filtered-out positions.
-            input_ids: Previously generated token IDs ``[batch, seq_len]``,
-                padded with 0. Used by frequency penalty.
-            input_mask: Boolean mask ``[batch, seq_len]``, True for real
-                tokens, False for padding. Used to exclude padding from
-                penalty computation.

        Returns:
            Transformed logits tensor.
        """
-        raise NotImplementedError


 class TemperatureStrategy(BaseSamplingStrategy):
@@ -53,21 +41,13 @@ class TemperatureStrategy(BaseSamplingStrategy):
    def __init__(self, temperature: Union[float, Tensor] = 1.0):
        self.temperature = temperature

-    def apply(
-        self,
-        logits: Tensor,
-        filter_value: float = -float("inf"),
-        input_ids: Optional[Tensor] = None,
-        input_mask: Optional[Tensor] = None,
-    ) -> Tensor:
+    def apply(self, logits, filter_value=-float("inf")):
        t = self.temperature
        if isinstance(t, Tensor):
-            t = t.to(logits.device, non_blocking=True).view(-1, 1)
-            t = torch.clamp(t, min=1e-8)
            if (t != 1.0).any():
-                logits = logits / t
+                logits = logits / t.to(logits.device, non_blocking=True).view(-1, 1)
        elif t != 1.0:
-            logits = logits / max(t, 1e-8)
+            logits = logits / t
        return logits


@@ -81,13 +61,7 @@ class TopKStrategy(BaseSamplingStrategy):
    def __init__(self, top_k: Union[int, Tensor] = 0):
        self.top_k = top_k

-    def apply(
-        self,
-        logits: Tensor,
-        filter_value: float = -float("inf"),
-        input_ids: Optional[Tensor] = None,
-        input_mask: Optional[Tensor] = None,
-    ) -> Tensor:
+    def apply(self, logits, filter_value=-float("inf")):
        tk = self.top_k
        if isinstance(tk, Tensor):
            tk = tk.to(logits.device, non_blocking=True).long().clamp(min=0)
@@ -124,9 +98,7 @@ class TopPStrategy(BaseSamplingStrategy):
    def __init__(self, top_p: Union[float, Tensor] = 1.0):
        self.top_p = top_p

-    def _apply(
-        self, logits: Tensor, top_p: Union[float, Tensor], filter_value: float
-    ) -> Tensor:
+    def _apply(self, logits, top_p, filter_value):
        sorted_logits, sorted_indices = torch.sort(logits, descending=True, dim=-1)
        cum_probs = torch.cumsum(torch.softmax(sorted_logits, dim=-1), dim=-1)
        remove = cum_probs > top_p
@@ -137,13 +109,7 @@ class TopPStrategy(BaseSamplingStrategy):
        logits[mask] = filter_value
        return logits

-    def apply(
-        self,
-        logits: Tensor,
-        filter_value: float = -float("inf"),
-        input_ids: Optional[Tensor] = None,
-        input_mask: Optional[Tensor] = None,
-    ) -> Tensor:
+    def apply(self, logits, filter_value=-float("inf")):
        tp = self.top_p
        if isinstance(tp, Tensor):
            tp = tp.to(logits.device, non_blocking=True)
@@ -154,84 +120,6 @@ class TopPStrategy(BaseSamplingStrategy):
        return logits


-class FrequencyPenaltyStrategy(BaseSamplingStrategy):
-    """Penalizes tokens based on how many times they appeared in history.
-
-    Subtracts ``penalty * count(token)`` from each token's logit, where
-    ``count(token)`` is the number of occurrences in the generation history
-    (prompt + output). A penalty of ``0.0`` disables the strategy.
-
-    Unlike repetition penalty (which only checks *presence*), frequency
-    penalty scales linearly with occurrence count: the first use is
-    penalized once, the third use three times. This allows natural
-    repetition of common words while suppressing degenerate loops.
-
-    Reference: OpenAI API ``frequency_penalty`` parameter.
-
-    Args:
-        penalty: Scalar or ``[batch]`` tensor (0.0 disables, range -2.0~2.0).
-    """
-
-    def __init__(self, penalty: Union[float, Tensor] = 0.0):
-        self.penalty = penalty
-
-    def apply(
-        self,
-        logits: Tensor,
-        filter_value: float = -float("inf"),
-        input_ids: Optional[Tensor] = None,
-        input_mask: Optional[Tensor] = None,
-    ) -> Tensor:
-        if input_ids is None:
-            return logits
-
-        p = self.penalty
-        if isinstance(p, Tensor):
-            p = p.to(logits.device, non_blocking=True).view(-1, 1)
-            if (p == 0.0).all():
-                return logits
-        elif p == 0.0:
-            return logits
-
-        input_ids = input_ids.to(logits.device, non_blocking=True)
-
-        if input_mask is not None:
-            input_mask = input_mask.to(logits.device, non_blocking=True)
-            masked_ids = input_ids.clone()
-            masked_ids[~input_mask] = -1
-        else:
-            masked_ids = input_ids
-
-        batch_sz, seq_len = masked_ids.shape
-        vocab_size = logits.size(-1)
-
-        if isinstance(p, Tensor):
-            penalty_per_row = p.expand(batch_sz, 1)
-        else:
-            penalty_per_row = torch.full(
-                (batch_sz, 1), float(p), device=logits.device, dtype=logits.dtype
-            )
-
-        counts = torch.zeros(
-            batch_sz, vocab_size, device=logits.device, dtype=logits.dtype
-        )
-        valid_mask = masked_ids >= 0
-        if valid_mask.any():
-            valid_ids = masked_ids[valid_mask]
-            row_indices = (
-                torch.arange(batch_sz, device=logits.device)
-                .unsqueeze(1)
-                .expand_as(masked_ids)[valid_mask]
-            )
-            counts.index_put_(
-                (row_indices, valid_ids),
-                torch.ones_like(valid_ids, dtype=logits.dtype),
-                accumulate=True,
-            )
-
-        return logits - penalty_per_row * counts
-
-
 class SamplingPipeline(BaseSamplingStrategy):
    """Composes multiple sampling strategies into a single transformation.

@@ -252,76 +140,25 @@ class SamplingPipeline(BaseSamplingStrategy):
    def __init__(self, strategies: List[BaseSamplingStrategy]):
        self.strategies = strategies

-    def apply(
-        self,
-        logits: Tensor,
-        filter_value: float = -float("inf"),
-        input_ids: Optional[Tensor] = None,
-        input_mask: Optional[Tensor] = None,
-    ) -> Tensor:
+    def apply(self, logits, filter_value=-float("inf")):
        for strategy in self.strategies:
-            logits = strategy.apply(logits, filter_value, input_ids, input_mask)
+            logits = strategy.apply(logits, filter_value)
        return logits

-    @staticmethod
-    def _is_greedy(temperature: Union[float, Tensor]) -> bool:
-        if isinstance(temperature, Tensor):
-            return temperature.numel() == 1 and temperature.item() == 0
-        return temperature == 0
-
-    @torch.inference_mode()
-    def sample(
-        self,
-        logits: Tensor,
-        filter_value: float = -float("inf"),
-        input_ids: Optional[Tensor] = None,
-        input_mask: Optional[Tensor] = None,
-        return_logprobs: bool = False,
-    ):
+    @torch.no_grad()
+    def sample(self, logits: Tensor, filter_value: float = -float("inf")) -> Tensor:
        """Apply strategies then sample (softmax + multinomial).

-        Short-circuits to ``argmax`` when temperature is exactly 0
-        (deterministic / greedy decode).
-
        Args:
            logits: Raw logits ``[batch, vocab_size]``.
-            input_ids: Previously generated token IDs ``[batch, seq_len]``.
-            input_mask: Boolean mask for ``input_ids`` padding.
-            return_logprobs: If ``True``, return ``(tokens, logprobs)``
-                where ``logprobs[i]`` is the log-probability of
-                ``tokens[i]`` under the (post-strategy) sampling
-                distribution.

        Returns:
-            Sampled token IDs ``[batch]``, or — when ``return_logprobs``
-            is ``True`` — a ``(token_ids, chosen_logprobs)`` tuple.
+            Sampled token IDs ``[batch]``.
        """
-        if self._is_greedy_pipeline():
-            tokens = logits.argmax(dim=-1)
-            if not return_logprobs:
-                return tokens
-            log_probs = torch.log_softmax(logits.float(), dim=-1)
-            chosen = torch.gather(log_probs, -1, tokens.unsqueeze(-1)).squeeze(-1)
-            return tokens, chosen
-
-        transformed = self.apply(logits, filter_value, input_ids, input_mask)
-        log_probs = torch.log_softmax(transformed.float(), dim=-1)
-        tokens = torch.multinomial(
-            torch.softmax(transformed, dim=-1), num_samples=1
+        return torch.multinomial(
+            torch.softmax(self.apply(logits, filter_value), dim=-1),
+            num_samples=1,
        ).squeeze(-1)
-        if not return_logprobs:
-            return tokens
-        chosen = torch.gather(log_probs, -1, tokens.unsqueeze(-1)).squeeze(-1)
-        return tokens, chosen
-
-    def _is_greedy_pipeline(self) -> bool:
-        """True if the first strategy is greedy temperature (temp=0)."""
-        if not self.strategies:
-            return False
-        first = self.strategies[0]
-        return isinstance(first, TemperatureStrategy) and self._is_greedy(
-            first.temperature
-        )


@torch.inference_mode()
@@ -330,46 +167,22 @@ def sample(
    temperature: Union[float, Tensor] = 1.0,
    top_k: Union[int, Tensor] = 0,
    top_p: Union[float, Tensor] = 1.0,
-    frequency_penalty: Union[float, Tensor] = 0.0,
-    input_ids: Optional[Tensor] = None,
-    input_mask: Optional[Tensor] = None,
    filter_value: float = -float("inf"),
-    return_logprobs: bool = False,
-):
+) -> Tensor:
    """Apply sampling strategies then sample (softmax + multinomial).

-    Shortcut for ``SamplingPipeline(...).sample(logits, return_logprobs=)``.
-
-    When **temperature** is exactly 0 (scalar or single-element tensor)
-    the function short-circuits to ``argmax`` for deterministic decode.
+    Shortcut for ``SamplingPipeline(...).sample(logits)``.

    Args:
        logits: Raw logits ``[batch, vocab_size]``.
-        frequency_penalty: Penalty per occurrence for repeated tokens
-            (0.0 disables, range -2.0~2.0).
-        input_ids: Previously generated token IDs ``[batch, seq_len]``.
-        input_mask: Boolean mask for ``input_ids`` padding.
-        return_logprobs: If ``True``, also return the log-probability
-            of each sampled token under the (post-strategy) sampling
-            distribution — useful for RL rollout (PPO/GRPO importance
-            ratios).

    Returns:
-        Sampled token IDs ``[batch]``, or — when ``return_logprobs`` is
-        ``True`` — a ``(token_ids, chosen_logprobs)`` tuple where
-        ``chosen_logprobs`` has shape ``[batch]``.
+        Sampled token IDs ``[batch]``.
    """
    return SamplingPipeline(
        [
            TemperatureStrategy(temperature),
            TopKStrategy(top_k),
            TopPStrategy(top_p),
-            FrequencyPenaltyStrategy(frequency_penalty),
        ]
-    ).sample(
-        logits,
-        filter_value=filter_value,
-        input_ids=input_ids,
-        input_mask=input_mask,
-        return_logprobs=return_logprobs,
-    )
+    ).sample(logits, filter_value)
@@ -2,24 +2,21 @@
 AutoModel base class for model loading and saving.
 """

+import json
 from contextlib import contextmanager
 from pathlib import Path
 from typing import Self, Union

+import safetensors.torch as st
 import torch.nn as nn

 from astrai.config.model_config import BaseModelConfig, ConfigFactory
 from astrai.factory import BaseFactory
-from astrai.serialization import load_model_config, load_model_weights, save_model


@contextmanager
 def _disable_random_init(enable: bool = True):
-    if not enable:
-        yield
-        return
-
-    names = (
+    init_functions = [
        "xavier_normal_",
        "xavier_uniform_",
        "kaiming_normal_",
@@ -29,15 +26,18 @@ def _disable_random_init(enable: bool = True):
        "constant_",
        "normal_",
        "uniform_",
-    )
-    orig = {n: getattr(nn.init, n) for n in names if hasattr(nn.init, n)}
-    for n in orig:
-        setattr(nn.init, n, lambda *a, **kw: None)
+    ]
+    original_funcs = {}
+    for name in init_functions:
+        if enable and hasattr(nn.init, name):
+            original_funcs[name] = getattr(nn.init, name)
+            setattr(nn.init, name, lambda *args, **kwargs: None)
    try:
        yield
    finally:
-        for n, fn in orig.items():
-            setattr(nn.init, n, fn)
+        if enable:
+            for name, orig_func in original_funcs.items():
+                setattr(nn.init, name, orig_func)


 class AutoModel(BaseFactory["AutoModel"], nn.Module):
@@ -60,22 +60,25 @@ class AutoModel(BaseFactory["AutoModel"], nn.Module):

        model_path = Path(path)

+        # Load config
        config_path = model_path / "config.json"
-        if not config_path.exists():
+        if config_path.exists():
+            with open(config_path, "r") as f:
+                raw = json.load(f)
+            config = ConfigFactory.load(raw)
+            model_type = config.model_type or "autoregressive_lm"
+        else:
            raise FileNotFoundError(f"Config file not found: {config_path}")

-        raw = load_model_config(str(model_path))
-        config = ConfigFactory.load(raw)
-        model_type = config.model_type or "autoregressive_lm"
-
        actual_cls = AutoModel.get_component_class(model_type)

        with _disable_random_init(enable=disable_random_init):
            model = actual_cls(config)

+        # Load weights
        weights_path = model_path / "model.safetensors"
        if weights_path.exists():
-            state_dict = load_model_weights(str(model_path))
+            state_dict = st.load_file(str(weights_path))
            model.load_state_dict(state_dict, strict=strict)

        return model
@@ -83,12 +86,15 @@ class AutoModel(BaseFactory["AutoModel"], nn.Module):
    def save_pretrained(
        self,
        save_directory: Union[str, Path],
-    ):
-        save_model(
-            config=self.config.to_dict(),
-            state_dict=self.state_dict(),
-            save_directory=str(save_directory),
-        )
+    ) -> None:
+        save_path = Path(save_directory)
+        save_path.mkdir(parents=True, exist_ok=True)
+
+        # Save config
+        self.config.to_file(str(save_path / "config.json"))
+
+        # Save weights
+        st.save_file(self.state_dict(), str(save_path / "model.safetensors"))

    def to(self, *args, **kwargs) -> Self:
        """Move model to device/dtype."""
@@ -6,7 +6,7 @@ import torch.nn.functional as F
 from torch import Tensor

 from astrai.factory import BaseFactory
-from astrai.inference.core.cache import CacheView
+from astrai.inference.core.cache import KvcacheView
 from astrai.model.components.linear import Linear
 from astrai.model.components.norm import RMSNorm
 from astrai.model.components.rope import apply_rotary_emb
@@ -24,7 +24,9 @@ def repeat_kv(x: Tensor, n_rep: int) -> Tensor:


 class AttnFactory(BaseFactory[nn.Module]):
-    pass
+    @classmethod
+    def create(cls, attn_type: str, **kwargs) -> nn.Module:
+        return super().create(attn_type, **kwargs)


@AttnFactory.register("gqa")
@@ -38,7 +40,6 @@ class GQA(nn.Module):
        norm_eps: float,
        use_gated_attention: bool,
        layer_id: int,
-        n_layers: int = 1,
    ):
        super().__init__()
        assert dim % n_heads == 0
@@ -56,7 +57,7 @@ class GQA(nn.Module):
        self.q_proj = Linear(dim, n_heads * self.head_dim)
        self.k_proj = Linear(dim, n_kv_heads * self.head_dim)
        self.v_proj = Linear(dim, n_kv_heads * self.head_dim)
-        self.o_proj = Linear(dim, dim, init_std=0.02 / (2 * n_layers) ** 0.5)
+        self.o_proj = Linear(dim, dim)

        if self.use_qk_norm:
            self.q_norm = RMSNorm(self.head_dim, norm_eps)
@@ -75,9 +76,10 @@ class GQA(nn.Module):
        x: Tensor,
        rotary_emb: Tensor,
        attn_mask: Tensor = None,
-        paged_cache: Optional[CacheView] = None,
-        is_causal: bool = False,
+        paged_cache: Optional[KvcacheView] = None,
    ) -> Tensor:
+        is_causal = attn_mask is None
+
        q = self._split_heads(self.q_proj(x), self.n_heads)
        k = self._split_heads(self.k_proj(x), self.n_kv_heads)
        v = self._split_heads(self.v_proj(x), self.n_kv_heads)
@@ -121,7 +123,6 @@ class MLA(nn.Module):
        use_qk_norm: bool,
        use_gated_attention: bool,
        layer_id: int,
-        n_layers: int = 1,
    ):
        super().__init__()
        self.dim = dim
@@ -149,9 +150,7 @@ class MLA(nn.Module):
            n_kv_heads * (2 * self.head_dim),
        )

-        self.o_proj = Linear(
-            dim, dim, bias=False, init_std=0.02 / (2 * n_layers) ** 0.5
-        )
+        self.o_proj = Linear(dim, dim, bias=False)

        if use_gated_attention:
            self.gate = Linear(dim, dim, bias=False)
@@ -161,10 +160,10 @@ class MLA(nn.Module):
        x: Tensor,
        rotary_emb: Tensor,
        attn_mask: Tensor = None,
-        paged_cache: Optional[CacheView] = None,
-        is_causal: bool = False,
+        paged_cache: Optional[KvcacheView] = None,
    ) -> Tensor:
        bsz, seq_len, _ = x.size()
+        is_causal = attn_mask is None

        q = self.q_proj(x)
        q = q.view(bsz, seq_len, self.n_heads, self.head_dim)
@@ -1,47 +1,57 @@
-from dataclasses import asdict
 from typing import Optional

 import torch.nn as nn
 from torch import Tensor

-from astrai.inference.core.cache import CacheView
+from astrai.inference.core.cache import KvcacheView
 from astrai.model.components.attention import AttnFactory
 from astrai.model.components.mlp import FFNFactory
 from astrai.model.components.norm import RMSNorm


 class DecoderBlock(nn.Module):
-    def __init__(self, config, layer_id: int):
+    def __init__(
+        self,
+        dim: int,
+        n_heads: int,
+        dim_ffn: int,
+        n_kv_heads: int,
+        norm_eps: float,
+        use_qk_norm: bool,
+        use_gated_attention: bool,
+        layer_id: int,
+        attn_type: str = "gqa",
+        ffn_type: str = "mlp",
+        **kwargs,
+    ):
        super().__init__()
-        cfg = asdict(config)
-        cfg.update(
-            dim=config.hidden_size,
-            dim_ffn=config.intermediate_size,
-            n_layers=config.num_hidden_layers,
-            n_heads=config.num_attention_heads,
-            n_kv_heads=config.num_key_value_heads,
-            norm_eps=config.rms_norm_eps,
-            down_init_std=0.02 / (2 * config.num_hidden_layers) ** 0.5,
+        self.attention = AttnFactory.create(
+            attn_type,
+            dim=dim,
+            n_heads=n_heads,
+            n_kv_heads=n_kv_heads,
+            use_qk_norm=use_qk_norm,
+            norm_eps=norm_eps,
+            use_gated_attention=use_gated_attention,
+            layer_id=layer_id,
+            **kwargs,
        )
-        self.attention = AttnFactory.create(config.attn_type, **cfg, layer_id=layer_id)
-        self.input_norm = RMSNorm(config.hidden_size, config.rms_norm_eps)
-        self.post_attention_norm = RMSNorm(config.hidden_size, config.rms_norm_eps)
-        self.mlp = FFNFactory.create(config.ffn_type, **cfg)
+        self.input_norm = RMSNorm(dim, norm_eps)
+        self.post_attention_norm = RMSNorm(dim, norm_eps)
+        self.mlp = FFNFactory.create(ffn_type, dim, dim_ffn, **kwargs)

    def forward(
        self,
        x: Tensor,
        rotary_emb: Tensor,
        attention_mask: Optional[Tensor] = None,
-        paged_cache: Optional[CacheView] = None,
-        is_causal: bool = False,
+        paged_cache: Optional[KvcacheView] = None,
    ) -> Tensor:
        attn_output = self.attention(
            self.input_norm(x),
            rotary_emb,
            attention_mask,
            paged_cache,
-            is_causal,
        )
        x = attn_output + x
        x = self.mlp(self.post_attention_norm(x)) + x
@@ -1,5 +1,3 @@
-import math
-
 import torch
 import torch.nn as nn
 import torch.nn.functional as F
@@ -7,20 +5,12 @@ from torch import Tensor


 class Embedding(nn.Module):
-    def __init__(self, vocab_size: int, embedding_dim: int, neftune_alpha: float = 0.0):
+    def __init__(self, vocab_size: int, embedding_dim: int):
        super().__init__()
        self.weight = nn.Parameter(torch.empty((vocab_size, embedding_dim)))
-        self.neftune_noise_alpha = neftune_alpha
-
-    def set_neftune_alpha(self, alpha: float):
-        self.neftune_noise_alpha = alpha

    def reset_parameters(self):
        nn.init.normal_(self.weight, mean=0.0, std=0.02)

    def forward(self, x: Tensor) -> Tensor:
-        out = F.embedding(x, self.weight)
-        if self.training and self.neftune_noise_alpha > 0.0:
-            eps = self.neftune_noise_alpha / math.sqrt(out.size(1))
-            out = out + eps * torch.randn_like(out)
-        return out
+        return F.embedding(x, self.weight)
@@ -5,16 +5,13 @@ from torch import Tensor


 class Linear(nn.Module):
-    def __init__(
-        self, in_dim: int, out_dim: int, bias: bool = False, init_std: float = 0.02
-    ):
+    def __init__(self, in_dim: int, out_dim: int, bias: bool = False):
        super().__init__()
        self.weight = nn.Parameter(torch.empty((out_dim, in_dim)))
        self.bias = nn.Parameter(torch.zeros(out_dim)) if bias else None
-        self.init_std = init_std

    def reset_parameters(self):
-        nn.init.normal_(self.weight, mean=0.0, std=self.init_std)
+        nn.init.kaiming_uniform_(self.weight, a=5**0.5)
        if self.bias is not None:
            fan_in, _ = nn.init._calculate_fan_in_and_fan_out(self.weight)
            bound = 1 / (fan_in**0.5)
@@ -1,19 +1,15 @@
+import json
 import logging
 from dataclasses import asdict, dataclass
 from pathlib import Path
 from typing import Optional, Set

+import safetensors.torch as st
 import torch
 import torch.nn as nn
 import torch.nn.functional as F

 from astrai.model.components.linear import Linear
-from astrai.serialization import (
-    load_json,
-    load_safetensors,
-    save_json,
-    save_safetensors,
-)

 logger = logging.getLogger(__name__)

@@ -39,12 +35,8 @@ class LoRALinear(nn.Module):

        self.r = r
        self.scaling = alpha / r
-        device = self.weight.device
-        dtype = self.weight.dtype
-        lora_a = torch.randn(r, self.weight.shape[1], device=device, dtype=dtype) / r
-        lora_b = torch.zeros(self.weight.shape[0], r, device=device, dtype=dtype)
-        self.lora_A = nn.Parameter(lora_a)
-        self.lora_B = nn.Parameter(lora_b)
+        self.lora_A = nn.Parameter(torch.randn(r, self.weight.shape[1]) / r)
+        self.lora_B = nn.Parameter(torch.zeros(self.weight.shape[0], r))
        self._merged = False

    def forward(self, x):
@@ -136,14 +128,16 @@ def save_lora(model: nn.Module, save_dir: str, config: LoRAConfig):

    path = Path(save_dir)
    path.mkdir(parents=True, exist_ok=True)
-    save_safetensors(lora_sd, path / "adapter_model.safetensors")
-    save_json(asdict(config), path / "adapter_config.json")
+    st.save_file(lora_sd, str(path / "adapter_model.safetensors"))
+    with open(path / "adapter_config.json", "w") as f:
+        json.dump(asdict(config), f, indent=2)
    logger.info("LoRA adapter saved to %s (%d keys)", save_dir, len(lora_sd))


 def load_lora(model: nn.Module, load_dir: str) -> LoRAConfig:
    path = Path(load_dir)
-    raw = load_json(path / "adapter_config.json")
+    with open(path / "adapter_config.json") as f:
+        raw = json.load(f)
    config = LoRAConfig(
        r=raw["r"], alpha=raw["alpha"], target_modules=tuple(raw["target_modules"])
    )
@@ -163,7 +157,7 @@ def load_lora(model: nn.Module, load_dir: str) -> LoRAConfig:
            target_modules=set(config.target_modules),
        )

-    weights = load_safetensors(path / "adapter_model.safetensors")
+    weights = st.load_file(str(path / "adapter_model.safetensors"))
    try:
        missing, unexpected = model.load_state_dict(weights, strict=False)
    except RuntimeError as e:
@@ -8,16 +8,18 @@ from astrai.model.components.linear import Linear


 class FFNFactory(BaseFactory[nn.Module]):
-    pass
+    @classmethod
+    def create(cls, ffn_type: str, dim: int, dim_ffn: int, **kwargs) -> nn.Module:
+        return super().create(ffn_type, dim, dim_ffn, **kwargs)


@FFNFactory.register("mlp")
 class MLP(nn.Module):
-    def __init__(self, dim: int, dim_ffn: int, down_init_std: float = 0.02):
+    def __init__(self, dim: int, dim_ffn: int):
        super().__init__()
        self.up = Linear(dim, dim_ffn)
        self.gate = Linear(dim, dim_ffn)
-        self.down = Linear(dim_ffn, dim, init_std=down_init_std)
+        self.down = Linear(dim_ffn, dim)

    def forward(self, x: Tensor) -> Tensor:
        gated = self.up(x) * F.silu(self.gate(x))
@@ -35,7 +37,6 @@ class DeepSeekMoE(nn.Module):
        n_shared_experts: int = 1,
        n_activated_experts: int = 2,
        topk_method: str = "greedy",
-        n_layers: int = 1,
    ):
        super().__init__()
        self.dim = dim
@@ -45,20 +46,12 @@ class DeepSeekMoE(nn.Module):
        self.topk_method = topk_method

        self.router = Linear(dim, n_routed_experts, bias=False)
-        moe_scale = 1 / max(n_shared_experts, 1) + 1 / n_activated_experts
-        down_init_std = 0.02 / (2 * n_layers * moe_scale) ** 0.5

        self.shared_experts = nn.ModuleList(
-            [
-                MLP(dim, dim_ffn, down_init_std=down_init_std)
-                for _ in range(n_shared_experts)
-            ]
+            [MLP(dim, dim_ffn) for _ in range(n_shared_experts)]
        )
        self.routed_experts = nn.ModuleList(
-            [
-                MLP(dim, dim_ffn, down_init_std=down_init_std)
-                for _ in range(n_routed_experts)
-            ]
+            [MLP(dim, dim_ffn) for _ in range(n_routed_experts)]
        )

    def forward(self, x: Tensor) -> Tensor:
@@ -1,4 +1,4 @@
-from typing import Dict, Optional
+from typing import Optional

 import torch
 import torch.nn as nn
@@ -19,10 +19,6 @@ def get_rotary_emb(
    return torch.complex(cos, sin)


-def ntk_base(base: float, dim: int, factor: float) -> float:
-    return base * (factor ** (dim / (dim - 2)))
-
-
 def apply_rotary_emb(x: torch.Tensor, freqs_cis: Tensor) -> Tensor:
    dtype = x.dtype
    x_ = x.float().reshape(*x.shape[:-1], -1, 2)
@@ -34,25 +30,11 @@ def apply_rotary_emb(x: torch.Tensor, freqs_cis: Tensor) -> Tensor:


 class RotaryEmbedding(nn.Module):
-    def __init__(
-        self,
-        dim: int,
-        max_len: int,
-        base: float = 10000,
-        rope_scaling: Optional[Dict] = None,
-    ):
+    def __init__(self, dim: int, max_len: int, base: float = 10000):
        super().__init__()
        self.dim = dim
        self.max_len = max_len
        self.base = base
-        self.rope_scaling = rope_scaling
-
-        if rope_scaling is not None:
-            scaling_type = rope_scaling.get("type", "ntk")
-            factor = rope_scaling.get("factor", 1.0)
-            if scaling_type == "ntk":
-                self.base = ntk_base(base, dim, factor)
-
        self._set_rotary_buffer(self.max_len)

    def _set_rotary_buffer(self, max_len: int):
@@ -18,28 +18,28 @@ class EmbeddingEncoder(AutoModel):
    def __init__(self, config: EncoderConfig):
        super().__init__(config)
        self.config = config
-        rope_dim = config.hidden_size // config.num_attention_heads
+        rope_dim = config.dim // config.n_heads
        rope_base = config.rope_theta if config.rope_theta is not None else 10000
-        self.rotary_embedding = RotaryEmbedding(
-            rope_dim,
-            config.max_position_embeddings,
-            rope_base,
-            rope_scaling=config.rope_scaling,
-        )
-        self.embed_tokens = Embedding(
-            config.vocab_size,
-            config.hidden_size,
-            neftune_alpha=config.neftune_alpha,
-        )
+        self.rotary_embedding = RotaryEmbedding(rope_dim, config.max_len, rope_base)
+        self.embed_tokens = Embedding(config.vocab_size, config.dim)

        self.layers = nn.ModuleList(
            [
-                DecoderBlock(config, layer_id)
-                for layer_id in range(config.num_hidden_layers)
+                DecoderBlock(
+                    config.dim,
+                    config.n_heads,
+                    config.dim_ffn,
+                    config.n_kv_heads,
+                    config.norm_eps,
+                    config.use_qk_norm,
+                    config.use_gated_attention,
+                    layer_id,
+                )
+                for layer_id in range(config.n_layers)
            ]
        )

-        self.norm = RMSNorm(config.hidden_size, config.rms_norm_eps)
+        self.norm = RMSNorm(config.dim, config.norm_eps)

        self.pooling_type = config.pooling_type or "mean"
        self.normalize_embeddings = config.normalize_embeddings or False
@@ -66,11 +66,14 @@ class EmbeddingEncoder(AutoModel):

        x = self.embed_tokens(input_ids)

+        if position_ids is None:
+            position_ids = torch.arange(S, device=x.device).unsqueeze(0).expand(B, -1)
+
        rotary_emb = self.rotary_embedding(x, position_ids)
-        attn_mask = process_attention_mask(input_mask)
+        attn_mask = process_attention_mask(x, position_ids, input_mask, is_causal=False)

        for layer in self.layers:
-            x = layer(x, rotary_emb, attn_mask)
+            x = layer(x, rotary_emb, attn_mask, paged_cache=None)

        hidden_states = self.norm(x)

@@ -1,11 +1,11 @@
-from typing import Any, Dict, Mapping, Optional
+from typing import Any, Mapping, Optional

 import torch
 import torch.nn as nn
 from torch import Tensor

 from astrai.config.model_config import AutoRegressiveLMConfig
-from astrai.inference.core.cache import CacheView
+from astrai.inference.core.cache import KvcacheView
 from astrai.model.automodel import AutoModel
 from astrai.model.components.decoder_block import DecoderBlock
 from astrai.model.components.embedding import Embedding
@@ -15,15 +15,35 @@ from astrai.model.components.rope import RotaryEmbedding


 def process_attention_mask(
-    input_mask: Optional[Tensor],
+    input_tensor: Tensor,
+    position_ids: Optional[Tensor],
+    input_mask: Optional[Tensor] = None,
+    is_causal: bool = False,
 ) -> Optional[Tensor]:
-    if input_mask is None:
+    if position_ids is None:
        return None
-    if input_mask.dim() == 2:
-        return input_mask[:, None, None, :]
-    if input_mask.dim() == 3:
-        return input_mask[:, None, :, :]
-    return input_mask
+    if input_mask is not None and input_mask.dim() > 2:
+        return input_mask
+
+    device = input_tensor.device
+    dtype = input_tensor.dtype
+    B, S = input_tensor.size()[:2]
+    T = position_ids.max().item() + 1
+
+    if input_mask is None:
+        if position_ids.min().item() == 0 and is_causal:
+            return None
+        pad = torch.ones(B, T, dtype=torch.bool, device=device)
+    else:
+        pad = input_mask[:, :T].to(device=device, dtype=torch.bool)
+
+    attend = pad.view(B, 1, T).expand(B, S, T).clone()
+    if is_causal:
+        attend &= position_ids.unsqueeze(-1) >= torch.arange(T, device=device)
+
+    return torch.full(
+        (B, 1, S, T), -torch.finfo(dtype).max / 2, dtype=dtype, device=device
+    ).masked_fill_(attend.unsqueeze(1), 0.0)


@AutoModel.register("autoregressive_lm")
@@ -36,32 +56,41 @@ class AutoRegressiveLM(AutoModel):
        rope_dim = (
            config.qk_rope_head_dim
            if config.attn_type == "mla"
-            else config.hidden_size // config.num_attention_heads
+            else config.dim // config.n_heads
        )
        rope_base = config.rope_theta if config.rope_theta is not None else 10000
-        self.rotary_embedding = RotaryEmbedding(
-            rope_dim,
-            config.max_position_embeddings,
-            rope_base,
-            rope_scaling=config.rope_scaling,
-        )
-        self.embed_tokens = Embedding(
-            config.vocab_size,
-            config.hidden_size,
-            neftune_alpha=config.neftune_alpha,
-        )
+        self.rotary_embedding = RotaryEmbedding(rope_dim, config.max_len, rope_base)
+        self.embed_tokens = Embedding(config.vocab_size, config.dim)

        self.layers = nn.ModuleList(
            [
-                DecoderBlock(config, layer_id)
-                for layer_id in range(config.num_hidden_layers)
+                DecoderBlock(
+                    config.dim,
+                    config.n_heads,
+                    config.dim_ffn,
+                    config.n_kv_heads,
+                    config.norm_eps,
+                    config.use_qk_norm,
+                    config.use_gated_attention,
+                    layer_id,
+                    attn_type=config.attn_type,
+                    ffn_type=config.ffn_type,
+                    n_routed_experts=config.n_routed_experts,
+                    n_shared_experts=config.n_shared_experts,
+                    n_activated_experts=config.n_activated_experts,
+                    topk_method=config.topk_method,
+                    kv_lora_rank=config.kv_lora_rank,
+                    qk_nope_head_dim=config.qk_nope_head_dim,
+                    qk_rope_head_dim=config.qk_rope_head_dim,
+                )
+                for layer_id in range(config.n_layers)
            ]
        )

-        self.norm = RMSNorm(config.hidden_size, config.rms_norm_eps)
-        self.lm_head = Linear(config.hidden_size, config.vocab_size)
+        self.norm = RMSNorm(config.dim, config.norm_eps)
+        self.lm_head = Linear(config.dim, config.vocab_size)

-        if self.config.tie_word_embeddings is True:
+        if self.config.tie_weight is True:
            self.lm_head.weight = self.embed_tokens.weight

        self.apply(self._init_weights)
@@ -76,7 +105,7 @@ class AutoRegressiveLM(AutoModel):

        state_dict = dict(state_dict)

-        if self.config.tie_word_embeddings is True:
+        if self.config.tie_weight is True:
            # same tensor for embed and lm_head
            if embed_key in state_dict:
                state_dict[lm_head_key] = state_dict[embed_key]
@@ -92,7 +121,7 @@ class AutoRegressiveLM(AutoModel):
            destination=destination, prefix=prefix, keep_vars=keep_vars
        )

-        if self.config.tie_word_embeddings is True:
+        if self.config.tie_weight is True:
            lm_head_key = prefix + "lm_head.weight"
            if lm_head_key in state_dict:
                del state_dict[lm_head_key]
@@ -103,18 +132,17 @@ class AutoRegressiveLM(AutoModel):
        self,
        input_ids: Tensor,
        input_mask: Optional[Tensor] = None,
-        paged_cache: Optional[CacheView] = None,
+        paged_cache: Optional[KvcacheView] = None,
        position_ids: Optional[Tensor] = None,
-    ) -> Dict[str, Tensor]:
+    ) -> Tensor:
        assert input_ids.ndim == 2

        x = self.embed_tokens(input_ids)
        rotary_emb = self.rotary_embedding(x, position_ids)
-        attn_mask = process_attention_mask(input_mask)
-        use_sdpa_causal_mask = attn_mask is None
+        attn_mask = process_attention_mask(x, position_ids, input_mask, is_causal=True)

        for layer in self.layers:
-            x = layer(x, rotary_emb, attn_mask, paged_cache, use_sdpa_causal_mask)
+            x = layer(x, rotary_emb, attn_mask, paged_cache)

        hidden_states = self.norm(x)
        logits = self.lm_head(hidden_states)
@@ -4,7 +4,6 @@ from astrai.parallel.executor import (
    BaseExecutor,
    DDPExecutor,
    ExecutorFactory,
-    FSDP2Executor,
    FSDPExecutor,
    GradientState,
    NoneExecutor,
@@ -36,5 +35,4 @@ __all__ = [
    "NoneExecutor",
    "DDPExecutor",
    "FSDPExecutor",
-    "FSDP2Executor",
 ]
@@ -2,24 +2,16 @@

 import contextlib
 import logging
-import os
 from contextlib import contextmanager
-from typing import Any, Callable, Optional, Tuple
+from typing import Optional, Tuple

 import torch
-import torch.distributed as dist
 import torch.nn as nn
-from torch.distributed.fsdp import (
-    FSDPModule,
-    FullStateDictConfig,
-    StateDictType,
-    fully_shard,
-)
 from torch.distributed.fsdp import FullyShardedDataParallel as FSDP
-from torch.distributed.tensor import DTensor
 from torch.nn.parallel import DistributedDataParallel as DDP
 from torch.optim import Optimizer
 from torch.optim.lr_scheduler import LRScheduler
+from torch.utils.data import DataLoader

 from astrai.factory import BaseFactory
 from astrai.parallel.setup import get_rank, get_world_size
@@ -91,25 +83,19 @@ class BaseExecutor:

    def prepare(
        self,
-        model_fn: Callable[[], nn.Module],
-        optimizer_fn: Optional[Callable[[nn.Module], Optimizer]] = None,
-        scheduler_fn: Optional[Callable[[Optimizer], LRScheduler]] = None,
-        before_wrap: Optional[Callable[[nn.Module], nn.Module]] = None,
-    ) -> Tuple[nn.Module, Optional[Optimizer], Optional[LRScheduler]]:
-        model = model_fn()
-        if before_wrap is not None:
-            model = before_wrap(model)
+        model: nn.Module,
+        optimizer: Optional[Optimizer] = None,
+        dataloader: Optional[DataLoader] = None,
+        scheduler: Optional[LRScheduler] = None,
+    ) -> Tuple[
+        nn.Module, Optional[Optimizer], Optional[DataLoader], Optional[LRScheduler]
+    ]:
        model = self._prepare_model(model)
-        optimizer = None
-        scheduler = None
-        if optimizer_fn is not None:
-            optimizer = optimizer_fn(model)
-            if scheduler_fn is not None:
-                scheduler = scheduler_fn(optimizer)
+        if optimizer is not None:
            optimizer = AccumOptimizer(optimizer, self.gradient_state)
-            if scheduler is not None:
-                scheduler = AccumScheduler(scheduler, self.gradient_state)
-        return model, optimizer, scheduler
+        if scheduler is not None:
+            scheduler = AccumScheduler(scheduler, self.gradient_state)
+        return model, optimizer, dataloader, scheduler

    def _prepare_model(self, model: nn.Module) -> nn.Module:
        return model
@@ -129,23 +115,8 @@ class BaseExecutor:
    def backward(self, loss: torch.Tensor):
        loss.backward()

-    def unwrap_model(self, model: nn.Module):
-        return model.state_dict()
-
-    @contextmanager
-    def checkpoint_context(self, model: nn.Module):
-        if self.use_distributed:
-            dist.barrier()
-        state_dict = self._gather_state_dict(model)
-        yield state_dict
-        if self.use_distributed:
-            dist.barrier()
-
-    def _gather_state_dict(self, model: nn.Module):
-        state_dict = self.unwrap_model(model)
-        if self.use_distributed and get_rank() != 0:
-            return None
-        return state_dict
+    def unwrap_model(self, model: nn.Module) -> nn.Module:
+        return model

    @property
    def use_distributed(self) -> bool:
@@ -159,12 +130,6 @@ class BaseExecutor:
    def grad_accum_steps(self) -> int:
        return self.gradient_state.num_steps

-    def clip_grad_norm(self, model: nn.Module, max_norm: float) -> float:
-        total_norm = torch.nn.utils.clip_grad_norm_(model.parameters(), max_norm)
-        if isinstance(total_norm, torch.Tensor):
-            return total_norm.item()
-        return total_norm
-

 class ExecutorFactory(BaseFactory[BaseExecutor]):
    pass
@@ -215,7 +180,7 @@ class DDPExecutor(BaseExecutor):
        if not self.use_distributed:
            logger.warning("DDP backend selected but world_size=1, model not wrapped")
            return model
-        local_rank = int(os.environ.get("LOCAL_RANK", get_rank()))
+        local_rank = get_rank()
        model = DDP(
            model,
            device_ids=[local_rank],
@@ -230,52 +195,17 @@ class DDPExecutor(BaseExecutor):
            return model.no_sync()
        return contextlib.nullcontext()

-    def unwrap_model(self, model: nn.Module):
+    def unwrap_model(self, model: nn.Module) -> nn.Module:
        if isinstance(model, DDP):
-            return model.module.state_dict()
-        return model.state_dict()
+            return model.module
+        return model


@ExecutorFactory.register("fsdp")
 class FSDPExecutor(BaseExecutor):
-    def __init__(
-        self,
-        grad_accum_steps: int = 1,
-        process_group=None,
-        sharding_strategy=None,
-        cpu_offload=None,
-        auto_wrap_policy=None,
-        backward_prefetch=None,
-        mixed_precision=None,
-        ignored_modules=None,
-        param_init_fn=None,
-        sync_module_states: bool = False,
-        forward_prefetch: bool = False,
-        limit_all_gathers: bool = True,
-        ignored_states=None,
-        device_mesh=None,
-    ):
+    def __init__(self, grad_accum_steps: int = 1, **fsdp_kwargs):
        super().__init__(grad_accum_steps=grad_accum_steps)
-        self._fsdp_kwargs = {
-            k: v
-            for k, v in dict(
-                process_group=process_group,
-                sharding_strategy=sharding_strategy,
-                cpu_offload=cpu_offload,
-                auto_wrap_policy=auto_wrap_policy,
-                backward_prefetch=backward_prefetch,
-                mixed_precision=mixed_precision,
-                ignored_modules=ignored_modules,
-                param_init_fn=param_init_fn,
-                sync_module_states=sync_module_states,
-                forward_prefetch=forward_prefetch,
-                limit_all_gathers=limit_all_gathers,
-                use_orig_params=True,
-                ignored_states=ignored_states,
-                device_mesh=device_mesh,
-            ).items()
-            if v is not None
-        }
+        self._fsdp_kwargs = fsdp_kwargs
        self._original_model: Optional[nn.Module] = None

    def _prepare_model(self, model: nn.Module) -> nn.Module:
@@ -293,115 +223,9 @@ class FSDPExecutor(BaseExecutor):
            return model.no_sync()
        return contextlib.nullcontext()

-    def clip_grad_norm(self, model: nn.Module, max_norm: float) -> float:
-        if isinstance(model, FSDP) and self.use_distributed:
-            total_norm = model.clip_grad_norm_(max_norm)
-            if isinstance(total_norm, torch.Tensor):
-                return total_norm.item()
-            return total_norm
-        return super().clip_grad_norm(model, max_norm)
-
-    def unwrap_model(self, model: nn.Module):
-        if isinstance(model, FSDP) and self.use_distributed:
-            with FSDP.state_dict_type(
-                model,
-                StateDictType.FULL_STATE_DICT,
-                FullStateDictConfig(offload_to_cpu=True, rank0_only=True),
-            ):
-                return model.state_dict()
-
-        return model.state_dict()
-
-
-@ExecutorFactory.register("fsdp2")
-class FSDP2Executor(BaseExecutor):
-    """FSDP2 executor using `torch.distributed.fsdp.fully_shard` (per-module API).
-
-    Wraps each child module individually via ``fully_shard``.
-    Skips the root model because ``ABC + Generic[T]`` in the MRO makes
-    FSDP2's dynamic ``__class__`` assignment fail at the CPython level.
-    Original ``Parameter`` objects are preserved (as DTensors) — no
-    ``FlatParameter``, no ``use_orig_params=True`` hack.
-    """
-
-    def __init__(
-        self,
-        grad_accum_steps: int = 1,
-        mesh: Optional[Any] = None,
-        mp_policy: Optional[Any] = None,
-        reshard_after_forward: bool = True,
-    ):
-        super().__init__(grad_accum_steps=grad_accum_steps)
-        self._mesh = mesh
-        self._mp_policy = mp_policy
-        self._reshard_after_forward = reshard_after_forward
-
-    def _prepare_model(self, model: nn.Module) -> nn.Module:
-        if not self.use_distributed:
-            logger.warning("FSDP2 backend selected but world_size=1, model not wrapped")
-            return model
-
-        kwargs = dict(
-            mesh=self._mesh,
-            mp_policy=self._mp_policy,
-            reshard_after_forward=self._reshard_after_forward,
-        )
-        kwargs = {k: v for k, v in kwargs.items() if v is not None}
-
-        for child in model.children():
-            if isinstance(child, nn.ModuleList):
-                for sub in child:
-                    fully_shard(sub, **kwargs)
-            else:
-                fully_shard(child, **kwargs)
-
-        logger.info(
-            "FSDP2 wrapping applied to %d direct children (root skipped for ABC compat)",
-            len(list(model.children())),
-        )
+    def unwrap_model(self, model: nn.Module) -> nn.Module:
+        if self._original_model is not None:
+            return self._original_model
+        if isinstance(model, FSDP):
+            return model._fsdp_wrapped_module
        return model
-
-    @contextmanager
-    def _no_sync(self, model: nn.Module):
-        fsdp_modules = [m for m in model.modules() if isinstance(m, FSDPModule)]
-        if fsdp_modules:
-            for m in fsdp_modules:
-                m.set_requires_gradient_sync(False, recurse=True)
-            try:
-                yield
-            finally:
-                for m in fsdp_modules:
-                    m.set_requires_gradient_sync(True, recurse=True)
-        else:
-            yield
-
-    def clip_grad_norm(self, model: nn.Module, max_norm: float) -> float:
-        if self.use_distributed:
-            total_norm = torch.nn.utils.clip_grad_norm_(model.parameters(), max_norm)
-            if isinstance(total_norm, torch.Tensor):
-                return total_norm.item()
-            return total_norm
-        return super().clip_grad_norm(model, max_norm)
-
-    def unwrap_model(self, model: nn.Module):
-        if not self.use_distributed:
-            return model.state_dict()
-
-        if get_rank() != 0:
-            return None
-
-        for module in model.modules():
-            if isinstance(module, FSDPModule):
-                module.unshard()
-
-        state_dict = model.state_dict()
-        result = {
-            k: (v.full_tensor() if isinstance(v, DTensor) else v)
-            for k, v in state_dict.items()
-        }
-
-        for module in model.modules():
-            if isinstance(module, FSDPModule):
-                module.reshard()
-
-        return result
@@ -1,27 +1,12 @@
-import logging
 import os
-import signal
-import socket
-import threading
-from abc import ABC, abstractmethod
 from contextlib import contextmanager
 from functools import wraps
-from typing import Callable, Optional
+from typing import Callable

 import torch
 import torch.distributed as dist
 import torch.multiprocessing as mp

-from astrai.parallel.signal_handler import install_early_signal_handlers
-
-logger = logging.getLogger(__name__)
-
-
-def find_free_port() -> str:
-    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
-        s.bind(("", 0))
-        return str(s.getsockname()[1])
-

 def get_current_device():
    return os.environ["LOCAL_DEVICE"]
@@ -45,7 +30,6 @@ def get_rank() -> int:
 def setup_parallel(
    rank: int,
    world_size: int,
-    local_rank: int,
    backend: str = "nccl",
    master_addr: str = "localhost",
    master_port: str = "29500",
@@ -57,26 +41,20 @@ def setup_parallel(
        return

    if world_size <= 1:
-        device_id = torch.device(device_type, local_rank)
-        os.environ["LOCAL_RANK"] = str(local_rank)
-        os.environ["WORLD_SIZE"] = "1"
-        os.environ["LOCAL_DEVICE"] = str(device_id)
        yield None
        return

-    device_id = torch.device(device_type, local_rank)
+    device_id = torch.device(device_type, rank)

    os.environ["MASTER_ADDR"] = master_addr
    os.environ["MASTER_PORT"] = master_port
-    os.environ["LOCAL_RANK"] = str(local_rank)
+    os.environ["LOCAL_RANK"] = str(rank)
    os.environ["WORLD_SIZE"] = str(world_size)
    os.environ["LOCAL_DEVICE"] = str(device_id)

-    pg_kwargs = dict(rank=rank, world_size=world_size, backend=backend)
-    if backend in ("nccl", "ccl"):
-        pg_kwargs["device_id"] = device_id
-
-    dist.init_process_group(**pg_kwargs)
+    dist.init_process_group(
+        rank=rank, world_size=world_size, backend=backend, device_id=device_id
+    )

    try:
        if backend == "nccl" and torch.cuda.is_available():
@@ -112,7 +90,7 @@ def only_on_rank(rank, sync=False):
    return decorator


-def _run_single_rank(
+def wrapper_spawn_func(
    rank: int,
    world_size: int,
    backend: str,
@@ -122,143 +100,20 @@ def _run_single_rank(
    func: Callable,
    kwargs: dict,
 ):
-    install_early_signal_handlers()
-    with setup_parallel(
-        rank=rank,
-        world_size=world_size,
-        local_rank=rank,
-        backend=backend,
-        master_addr=master_addr,
-        master_port=master_port,
-        device_type=device_type,
-    ):
-        func(**kwargs)
-
-
-class LaunchStrategy(ABC):
-    """Strategy for launching a function in a distributed context."""
-
-    def __init__(
-        self,
-        world_size: int,
-        backend: str,
-        master_addr: str,
-        master_port: str,
-        device_type: str,
-        start_method: str,
-    ):
-        self.world_size = world_size
-        self.backend = backend
-        self.master_addr = master_addr
-        self.master_port = master_port
-        self.device_type = device_type
-        self.start_method = start_method
-
-    @abstractmethod
-    def launch(self, func: Callable, **kwargs):
-        raise NotImplementedError
-
-
-class TorchrunStrategy(LaunchStrategy):
-    """External orchestrator (torchrun, SLURM, K8s) — env vars pre-set."""
-
-    def launch(self, func: Callable, **kwargs):
-        install_early_signal_handlers()
-        rank = int(os.environ["RANK"])
-        world_size = int(os.environ["WORLD_SIZE"])
-        local_rank = int(os.environ.get("LOCAL_RANK", rank))
+    try:
        with setup_parallel(
            rank=rank,
            world_size=world_size,
-            local_rank=local_rank,
-            backend=self.backend,
-            master_addr=os.environ.get("MASTER_ADDR", self.master_addr),
-            master_port=os.environ.get("MASTER_PORT", self.master_port),
-            device_type=self.device_type,
+            backend=backend,
+            master_addr=master_addr,
+            master_port=master_port,
+            device_type=device_type,
        ):
            func(**kwargs)

-
-class LocalStrategy(LaunchStrategy):
-    """Local launcher — single-process or mp.start_processes."""
-
-    def launch(self, func: Callable, **kwargs):
-        args = (
-            self.world_size,
-            self.backend,
-            self.master_addr,
-            self.master_port,
-            self.device_type,
-            func,
-            kwargs,
-        )
-
-        if self.world_size == 1:
-            _run_single_rank(0, *args)
-            return
-
-        install_early_signal_handlers()
-        ctx = mp.start_processes(
-            _run_single_rank,
-            args=args,
-            nprocs=self.world_size,
-            start_method=self.start_method,
-            join=False,
-        )
-
-        parent_stop = threading.Event()
-        original_handlers = {}
-
-        def _parent_handler(signum, frame):
-            sig = signal.Signals(signum)
-            logger.warning(
-                "Parent (pid=%d) received %s, forwarding to children...",
-                os.getpid(),
-                sig.name,
-            )
-            parent_stop.set()
-            for p in ctx.processes:
-                if p.is_alive():
-                    p.terminate()
-
-        for sig in (signal.SIGTERM, signal.SIGINT):
-            prev = signal.signal(sig, _parent_handler)
-            if prev not in (signal.SIG_DFL, signal.SIG_IGN, None, _parent_handler):
-                original_handlers[sig] = prev
-
-        try:
-            while not ctx.join() and not parent_stop.is_set():
-                pass
-        except BaseException:
-            logger.warning(
-                "Parent received unexpected exception, terminating children..."
-            )
-            for p in ctx.processes:
-                if p.is_alive():
-                    p.terminate()
-            raise
-        finally:
-            for sig, handler in original_handlers.items():
-                signal.signal(sig, handler)
-
-            for p in ctx.processes:
-                p.join()
-
-            ctx.join()
-
-
-def _detect_launcher() -> str:
-    """Detect the distributed launcher from environment.
-
-    Returns one of: "torchelastic", "torchrun", "external", "local".
-    """
-    if dist.is_torchelastic_launched():
-        return "torchelastic"
-    if "LOCAL_WORLD_SIZE" in os.environ:
-        return "torchrun"
-    if "RANK" in os.environ and "WORLD_SIZE" in os.environ:
-        return "external"
-    return "local"
+    except Exception as e:
+        print(f"Error in rank {rank}: {e}")
+        raise


 def spawn_parallel_fn(
@@ -266,20 +121,46 @@ def spawn_parallel_fn(
    world_size: int,
    backend: str = "nccl",
    master_addr: str = "localhost",
-    master_port: Optional[str] = None,
+    master_port: str = "29500",
    device_type: str = "cuda",
    start_method: str = "spawn",
    **kwargs,
 ):
-    if master_port is None:
-        master_port = find_free_port()
-    launcher = _detect_launcher()
-    if launcher in ("torchelastic", "torchrun", "external"):
-        strategy = TorchrunStrategy(
-            world_size, backend, master_addr, master_port, device_type, start_method
-        )
-    else:
-        strategy = LocalStrategy(
-            world_size, backend, master_addr, master_port, device_type, start_method
-        )
-    strategy.launch(func, **kwargs)
+    # clear environment variables
+    for key in [
+        "MASTER_ADDR",
+        "MASTER_PORT",
+        "RANK",
+        "WORLD_SIZE",
+        "LOCAL_RANK",
+        "LOCAL_DEVICE",
+    ]:
+        if key in os.environ:
+            del os.environ[key]
+
+    if world_size == 1:
+        device_id = torch.device(device_type, 0)
+        os.environ["LOCAL_RANK"] = "0"
+        os.environ["WORLD_SIZE"] = "1"
+        os.environ["LOCAL_DEVICE"] = str(device_id)
+
+        func(**kwargs)
+        return
+
+    wrapper_spawn_func_args = (
+        world_size,
+        backend,
+        master_addr,
+        master_port,
+        device_type,
+        func,
+        kwargs,
+    )
+
+    mp.start_processes(
+        wrapper_spawn_func,
+        args=wrapper_spawn_func_args,
+        nprocs=world_size,
+        start_method=start_method,
+        join=True,
+    )
@@ -1,53 +0,0 @@
-import logging
-import os
-import signal
-import threading
-
-logger = logging.getLogger(__name__)
-
-_early_stop = threading.Event()
-_active_context = None
-
-
-def _early_handler(signum: int, frame):
-    sig = signal.Signals(signum)
-    logger.warning(
-        "Received %s (pid=%d), requesting graceful training stop...",
-        sig.name,
-        os.getpid(),
-    )
-    _early_stop.set()
-    if _active_context is not None:
-        _active_context.request_stop()
-
-
-def install_early_signal_handlers():
-    for sig in (signal.SIGTERM, signal.SIGINT):
-        signal.signal(sig, _early_handler)
-    _unblock_signals()
-
-
-def _unblock_signals():
-    try:
-        mask = signal.pthread_sigmask(signal.SIG_BLOCK, set())
-        blocked = {signal.SIGTERM, signal.SIGINT} & mask
-        if blocked:
-            signal.pthread_sigmask(signal.SIG_UNBLOCK, blocked)
-    except (AttributeError, OSError):
-        pass
-
-
-def register_signal_handlers(context):
-    global _active_context
-    _active_context = context
-    for sig in (signal.SIGTERM, signal.SIGINT):
-        signal.signal(sig, _early_handler)
-    if _early_stop.is_set():
-        context.request_stop()
-        logger.warning("Signal was received during initialization, stopping...")
-
-
-def unregister_signal_handlers():
-    global _active_context
-    _active_context = None
-    _early_stop.clear()
@@ -1,40 +0,0 @@
-from astrai.preprocessing.builder import (
-    BaseMaskBuilder,
-    MaskBuilderFactory,
-    MultiOutputMaskBuilder,
-    SectionedMaskBuilder,
-    SingleOutputMaskBuilder,
-)
-from astrai.preprocessing.packing import (
-    PackingStrategy,
-    PackingStrategyFactory,
-    plan_bfd,
-)
-from astrai.preprocessing.pipeline import Pipeline, filter_by_length
-from astrai.preprocessing.position_id import (
-    PositionIdStrategy,
-    PositionIdStrategyFactory,
-)
-from astrai.preprocessing.transform import TokenizeTransform
-from astrai.preprocessing.writer import (
-    StoreWriter,
-    StoreWriterFactory,
-)
-
-__all__ = [
-    "BaseMaskBuilder",
-    "MaskBuilderFactory",
-    "MultiOutputMaskBuilder",
-    "PackingStrategy",
-    "PackingStrategyFactory",
-    "Pipeline",
-    "PositionIdStrategy",
-    "PositionIdStrategyFactory",
-    "SectionedMaskBuilder",
-    "SingleOutputMaskBuilder",
-    "StoreWriter",
-    "StoreWriterFactory",
-    "TokenizeTransform",
-    "filter_by_length",
-    "plan_bfd",
-]
@@ -1,537 +0,0 @@
-"""Mask building for preprocessing pipeline.
-
-:class:`SectionRenderer` converts section specs into token ids and loss
-masks (template / text / value extraction).  :class:`SingleOutputMaskBuilder`
-handles single-output (SFT / pretrain), :class:`MultiOutputMaskBuilder`
-handles multi-output (DPO / GRPO), and :class:`SectionedMaskBuilder`
-orchestrates both modes as a façade.
-"""
-
-from abc import ABC, abstractmethod
-from typing import Optional
-
-from astrai.factory import BaseFactory
-
-
-def _extract_domain(item: dict, domain_key: Optional[str]) -> str:
-    if not domain_key:
-        return "__default__"
-    val = item.get(domain_key, "__default__")
-    return val if isinstance(val, str) else "__default__"
-
-
-def _resolve_action(action: str, role: str, config) -> str:
-    if action == "$role":
-        return config.mask.get(role, config.mask_default)
-    return action
-
-
-class SectionRenderer:
-    """Render section specs into ``(ids, loss_mask)`` tuples."""
-
-    def process_sections(
-        self,
-        item: dict,
-        sections: list,
-        config,
-        tokenizer,
-        *,
-        is_top_level: bool = False,
-    ):
-        all_ids: list[int] = []
-        loss_mask: list[int] = []
-
-        has_template = any(s.get("template") for s in sections)
-        is_text_config = not has_template and all(
-            s["action"] == "train" for s in sections
-        )
-
-        if is_top_level and has_template and tokenizer.bos_token_id is not None:
-            all_ids.append(tokenizer.bos_token_id)
-            loss_mask.append(0)
-
-        first_section = True
-        for sec in sections:
-            field = sec["field"]
-            action = sec["action"]
-            use_template = sec.get("template", False)
-            add_special = sec.get(
-                "add_special_tokens", not use_template and first_section
-            )
-
-            if use_template:
-                success = self._append_template(
-                    item, field, action, tokenizer, config, all_ids, loss_mask
-                )
-                if not success:
-                    continue
-            else:
-                success = self._append_text(
-                    item,
-                    field,
-                    action,
-                    tokenizer,
-                    add_special,
-                    is_text_config,
-                    config,
-                    all_ids,
-                    loss_mask,
-                )
-                if not success:
-                    continue
-
-            first_section = False
-
-        max_len = config.preprocessing.max_seq_len
-        all_ids = all_ids[:max_len]
-        loss_mask = loss_mask[: len(all_ids)]
-
-        if not all_ids:
-            return None, None
-
-        if is_top_level and has_template and len(all_ids) <= 1:
-            return None, None
-
-        return all_ids, loss_mask
-
-    def process_sections_batch(
-        self,
-        items: list[dict],
-        sections: list,
-        config,
-        tokenizer,
-        *,
-        is_top_level=False,
-        filter_text=True,
-    ):
-        """Render and tokenize a group of records with batched Rust tokenization."""
-        has_template = any(s.get("template") for s in sections)
-        is_text_config = not has_template and all(
-            s["action"] == "train" for s in sections
-        )
-        plans: list[list[tuple[str, str, bool]]] = []
-
-        for item in items:
-            plan: list[tuple[str, str, bool]] = []
-            first_section = True
-            for sec in sections:
-                field = sec["field"]
-                action = sec["action"]
-                use_template = sec.get("template", False)
-                add_special = sec.get(
-                    "add_special_tokens", not use_template and first_section
-                )
-
-                if use_template:
-                    messages = item.get(field)
-                    if not isinstance(messages, list) or not messages:
-                        continue
-                    for msg in messages:
-                        role = msg.get("role", "")
-                        rendered = tokenizer.apply_chat_template(
-                            [msg], tokenize=False, add_generation_prompt=False
-                        )
-                        plan.append(
-                            (rendered, _resolve_action(action, role, config), False)
-                        )
-                else:
-                    text = str(item.get(field, ""))
-                    if not text.strip():
-                        continue
-                    if is_text_config and filter_text:
-                        pp = config.preprocessing
-                        if pp.min_chars > 0 and len(text) < pp.min_chars:
-                            continue
-                        if len(text) > pp.max_chars:
-                            continue
-                    plan.append((text, action, add_special))
-
-                first_section = False
-            plans.append(plan)
-
-        encoded: dict[tuple[int, int], list[int]] = {}
-        for add_special in (False, True):
-            refs = [
-                (item_idx, unit_idx, text)
-                for item_idx, plan in enumerate(plans)
-                for unit_idx, (text, _, add) in enumerate(plan)
-                if add == add_special
-            ]
-            if not refs:
-                continue
-            ids_batch = tokenizer.encode(
-                [text for _, _, text in refs], add_special_tokens=add_special
-            )
-            for (item_idx, unit_idx, _), ids in zip(refs, ids_batch):
-                encoded[(item_idx, unit_idx)] = ids
-
-        outputs = []
-        max_len = config.preprocessing.max_seq_len
-        for item_idx, plan in enumerate(plans):
-            all_ids = []
-            loss_mask = []
-            if is_top_level and has_template and tokenizer.bos_token_id is not None:
-                all_ids.append(tokenizer.bos_token_id)
-                loss_mask.append(0)
-            for unit_idx, (_, action, _) in enumerate(plan):
-                ids = encoded[(item_idx, unit_idx)]
-                all_ids.extend(ids)
-                loss_mask.extend([1 if action == "train" else 0] * len(ids))
-            all_ids = all_ids[:max_len]
-            loss_mask = loss_mask[: len(all_ids)]
-            if not all_ids or (is_top_level and has_template and len(all_ids) <= 1):
-                outputs.append((None, None))
-            else:
-                outputs.append((all_ids, loss_mask))
-        return outputs
-
-    def process_list_field(self, item: dict, sections: list, config, tokenizer):
-        """Tokenize a list-valued field, preserving per-element boundaries.
-
-        Returns ``(list_of_id_lists, list_of_mask_lists)`` where each
-        inner list corresponds to one element of the source list.  This
-        is critical for GRPO where each response must stay a separate
-        sequence so the strategy can form a ``[G, R]`` tensor.
-        """
-        per_item_ids: list[list[int]] = []
-        per_item_masks: list[list[int]] = []
-
-        for sec in sections:
-            field = sec["field"]
-            action = sec["action"]
-            use_template = sec.get("template", False)
-
-            values = item.get(field)
-            if not isinstance(values, list):
-                continue
-
-            for val in values:
-                ids: list[int] = []
-                mask: list[int] = []
-                if use_template:
-                    if isinstance(val, list):
-                        wrapper = {field: val}
-                        self._append_template(
-                            wrapper, field, action, tokenizer, config, ids, mask
-                        )
-                else:
-                    wrapper = {field: str(val)}
-                    self._append_text(
-                        wrapper,
-                        field,
-                        action,
-                        tokenizer,
-                        False,
-                        False,
-                        config,
-                        ids,
-                        mask,
-                    )
-                if ids:
-                    max_len = config.preprocessing.max_seq_len
-                    ids = ids[:max_len]
-                    mask = mask[: len(ids)]
-                    per_item_ids.append(ids)
-                    per_item_masks.append(mask)
-
-        if not per_item_ids:
-            return None, None
-        return per_item_ids, per_item_masks
-
-    def process_list_field_batch(self, items, sections, config, tokenizer):
-        per_item_ids = [[] for _ in items]
-        per_item_masks = [[] for _ in items]
-
-        for sec in sections:
-            wrappers = []
-            owners = []
-            field = sec["field"]
-            for item_idx, item in enumerate(items):
-                values = item.get(field)
-                if not isinstance(values, list):
-                    continue
-                for val in values:
-                    if sec.get("template", False) and not isinstance(val, list):
-                        continue
-                    wrappers.append({field: val if isinstance(val, list) else str(val)})
-                    owners.append(item_idx)
-
-            rendered = self.process_sections_batch(
-                wrappers,
-                [sec],
-                config,
-                tokenizer,
-                is_top_level=False,
-                filter_text=False,
-            )
-            for owner, (ids, mask) in zip(owners, rendered):
-                if ids:
-                    per_item_ids[owner].append(ids)
-                    per_item_masks[owner].append(mask)
-
-        return [
-            (ids, masks) if ids else (None, None)
-            for ids, masks in zip(per_item_ids, per_item_masks)
-        ]
-
-    @staticmethod
-    def is_value_section(sections: list) -> bool:
-        return len(sections) == 1 and sections[0].get("action") == "value"
-
-    @staticmethod
-    def extract_raw_value(item: dict, sections: list):
-        sec = sections[0]
-        field = sec["field"]
-        raw = item.get(field)
-        if raw is None:
-            return None
-        if isinstance(raw, list):
-            return [float(v) for v in raw]
-        return [float(raw)]
-
-    def _append_template(
-        self, item, field, action, tokenizer, config, all_ids, loss_mask
-    ):
-        messages = item.get(field)
-        if not isinstance(messages, list) or not messages:
-            return False
-        for msg in messages:
-            role = msg.get("role", "")
-            act = _resolve_action(action, role, config)
-            rendered = tokenizer.apply_chat_template(
-                [msg], tokenize=False, add_generation_prompt=False
-            )
-            ids = tokenizer.encode(rendered, add_special_tokens=False)
-            all_ids.extend(ids)
-            val = 1 if act == "train" else 0
-            loss_mask.extend([val] * len(ids))
-        return True
-
-    def _append_text(
-        self,
-        item,
-        field,
-        action,
-        tokenizer,
-        add_special,
-        is_text_config,
-        config,
-        all_ids,
-        loss_mask,
-    ):
-        text = str(item.get(field, ""))
-        if not text.strip():
-            return False
-        if is_text_config:
-            pp = config.preprocessing
-            if pp.min_chars > 0 and len(text) < pp.min_chars:
-                return False
-            if len(text) > pp.max_chars:
-                return False
-        ids = tokenizer.encode(text, add_special_tokens=add_special)
-        all_ids.extend(ids)
-        val = 1 if action == "train" else 0
-        loss_mask.extend([val] * len(ids))
-        return True
-
-
-class BaseMaskBuilder(ABC):
-    """Convert a JSONL item into token ids and optional loss_mask."""
-
-    @abstractmethod
-    def build(self, item: dict, config, tokenizer) -> Optional[dict]: ...
-
-    def build_batch(self, items: list[dict], config, tokenizer) -> list[Optional[dict]]:
-        return [self.build(item, config, tokenizer) for item in items]
-
-
-class MaskBuilderFactory(BaseFactory["BaseMaskBuilder"]):
-    pass
-
-
-@MaskBuilderFactory.register("single")
-class SingleOutputMaskBuilder(BaseMaskBuilder):
-    """Build a single output sequence with optional loss mask.
-
-    Expects ``config.input.sections`` (list of section specs).
-    """
-
-    def __init__(self, renderer: Optional[SectionRenderer] = None):
-        self.renderer = renderer or SectionRenderer()
-
-    def build(self, item: dict, config, tokenizer) -> Optional[dict]:
-        sections = config.input.sections
-        if not sections:
-            return None
-
-        ids, mask = self.renderer.process_sections(
-            item, sections, config, tokenizer, is_top_level=True
-        )
-        if ids is None:
-            return None
-
-        result: dict = {
-            "sequence": ids,
-            "domain": _extract_domain(item, config.output.domain_key),
-        }
-        if not all(m == 1 for m in mask):
-            result["loss_mask"] = mask
-        return result
-
-    def build_batch(self, items, config, tokenizer):
-        sections = config.input.sections
-        if not sections:
-            return [None] * len(items)
-        rendered = self.renderer.process_sections_batch(
-            items, sections, config, tokenizer, is_top_level=True
-        )
-        results = []
-        for item, (ids, mask) in zip(items, rendered):
-            if ids is None:
-                results.append(None)
-                continue
-            result = {
-                "sequence": ids,
-                "domain": _extract_domain(item, config.output.domain_key),
-            }
-            if not all(m == 1 for m in mask):
-                result["loss_mask"] = mask
-            results.append(result)
-        return results
-
-
-@MaskBuilderFactory.register("multi")
-class MultiOutputMaskBuilder(BaseMaskBuilder):
-    """Build multiple output sequences (DPO / GRPO).
-
-    Expects ``config.input.sources`` (dict of output_key → spec).
-    """
-
-    def __init__(self, renderer: Optional[SectionRenderer] = None):
-        self.renderer = renderer or SectionRenderer()
-
-    def build(self, item: dict, config, tokenizer) -> Optional[dict]:
-        sources_spec = getattr(config.input, "sources", None)
-        if not sources_spec:
-            return None
-
-        result: dict = {}
-        any_output = False
-
-        for output_key, spec in sources_spec.items():
-            sections = spec.get("sections", [])
-            if not sections:
-                continue
-
-            if self.renderer.is_value_section(sections):
-                ids = self.renderer.extract_raw_value(item, sections)
-                if ids is None:
-                    continue
-                result[output_key] = ids
-                any_output = True
-                continue
-
-            list_field = spec.get("list_field", False)
-            mask_key = spec.get("mask_key", f"{output_key}_mask")
-
-            if list_field:
-                ids, mask = self.renderer.process_list_field(
-                    item, sections, config, tokenizer
-                )
-                if ids is None:
-                    continue
-                # ids is List[List[int]] — preserve per-response structure
-                result[output_key] = ids
-                if mask is not None:
-                    result[mask_key] = mask
-                any_output = True
-                continue
-
-            ids, mask = self.renderer.process_sections(
-                item, sections, config, tokenizer, is_top_level=True
-            )
-
-            if ids is None:
-                continue
-
-            result[output_key] = ids
-            if not all(m == 1 for m in mask):
-                result[mask_key] = mask
-            elif "mask_key" in spec:
-                result[mask_key] = mask
-
-            any_output = True
-
-        if not any_output:
-            return None
-
-        result["domain"] = _extract_domain(item, config.output.domain_key)
-        return result
-
-    def build_batch(self, items, config, tokenizer):
-        sources_spec = getattr(config.input, "sources", None)
-        if not sources_spec:
-            return [None] * len(items)
-
-        results = [{} for _ in items]
-        for output_key, spec in sources_spec.items():
-            sections = spec.get("sections", [])
-            if not sections:
-                continue
-            if self.renderer.is_value_section(sections):
-                for item, result in zip(items, results):
-                    value = self.renderer.extract_raw_value(item, sections)
-                    if value is not None:
-                        result[output_key] = value
-                continue
-
-            mask_key = spec.get("mask_key", f"{output_key}_mask")
-            if spec.get("list_field", False):
-                rendered = self.renderer.process_list_field_batch(
-                    items, sections, config, tokenizer
-                )
-            else:
-                rendered = self.renderer.process_sections_batch(
-                    items, sections, config, tokenizer, is_top_level=True
-                )
-
-            for result, (ids, mask) in zip(results, rendered):
-                if ids is None:
-                    continue
-                result[output_key] = ids
-                if spec.get("list_field", False) or not all(m == 1 for m in mask):
-                    result[mask_key] = mask
-                elif "mask_key" in spec:
-                    result[mask_key] = mask
-
-        return [
-            ({**result, "domain": _extract_domain(item, config.output.domain_key)})
-            if result
-            else None
-            for item, result in zip(items, results)
-        ]
-
-
-@MaskBuilderFactory.register("sectioned")
-class SectionedMaskBuilder(BaseMaskBuilder):
-    """Façade that dispatches to SingleOutputMaskBuilder or MultiOutputMaskBuilder.
-
-    Preserves backward compatibility for existing configs and code that rely
-    on the ``"sectioned"`` factory name.
-    """
-
-    def __init__(self):
-        self._single = SingleOutputMaskBuilder()
-        self._multi = MultiOutputMaskBuilder()
-
-    def build(self, item: dict, config, tokenizer) -> Optional[dict]:
-        sources_spec = getattr(config.input, "sources", None)
-        if sources_spec:
-            return self._multi.build(item, config, tokenizer)
-        return self._single.build(item, config, tokenizer)
-
-    def build_batch(self, items, config, tokenizer):
-        sources_spec = getattr(config.input, "sources", None)
-        if sources_spec:
-            return self._multi.build_batch(items, config, tokenizer)
-        return self._single.build_batch(items, config, tokenizer)
@@ -1,124 +0,0 @@
-"""Shared preprocessing kernel used by both :class:`Pipeline` and
-:class:`TokenizeTransform`.
-
-The two entry points previously duplicated ~60 % of their logic:
-record iteration, mask-builder invocation, primary-id extraction,
-per-key accumulation, dtype inference and position-id generation.
-This module factors out the common core as pure functions so that
-the online (``TokenizeTransform``) and offline (``Pipeline``) paths
-stay in lockstep.
-"""
-
-from itertools import chain
-from typing import Dict, Iterator, List, Optional
-
-import torch
-
-from astrai.config.preprocess_config import PipelineConfig
-from astrai.preprocessing.builder import MaskBuilderFactory
-from astrai.preprocessing.position_id import PositionIdStrategyFactory
-from astrai.tokenize import AutoTokenizer
-
-
-def build_preprocessing_components(config: PipelineConfig, tokenizer_path: str):
-    """Load tokenizer, mask builder and position-id strategy together.
-
-    Both ``Pipeline`` and ``TokenizeTransform`` need the same triple;
-    centralising the construction avoids drift (e.g. one path forgetting
-    to create the position-id strategy).
-    """
-    tokenizer = AutoTokenizer.from_pretrained(tokenizer_path)
-    mask_builder = MaskBuilderFactory.create("sectioned")
-    position_strategy = PositionIdStrategyFactory.create(
-        config.output.position_ids_mode
-    )
-    return tokenizer, mask_builder, position_strategy
-
-
-def primary_ids(result: dict) -> List[int]:
-    """Return the first flat int-list value in *result*.
-
-    Used for token counting and position-id generation when the
-    primary key name is not known (DPO uses ``chosen``, GRPO uses
-    ``prompts``, SFT uses ``sequence``).
-    """
-    for val in result.values():
-        if isinstance(val, list) and val and isinstance(val[0], int):
-            return val
-    return []
-
-
-def infer_dtype(ids: List) -> torch.dtype:
-    """Float values become float32, everything else int32."""
-    if ids and isinstance(ids[0], float):
-        return torch.float32
-    return torch.int32
-
-
-def iter_raw_records(
-    records: List[dict],
-    mask_builder,
-    config: PipelineConfig,
-    tokenizer,
-) -> Iterator[dict]:
-    """Yield mask-builder output dicts for each record, skipping failures.
-
-    Drops ``domain`` from the result (callers that need it should read
-    it before calling this).  Each yielded dict maps a key
-    (``sequence``, ``chosen``, ``responses``…) to either a flat
-    ``List[int]`` or a nested ``List[List[int]]`` (GRPO responses/masks).
-    """
-    for item in records:
-        result = mask_builder.build(item, config, tokenizer)
-        if result is None:
-            continue
-        result.pop("domain", None)
-        if not primary_ids(result):
-            continue
-        yield result
-
-
-def to_per_record_tensors(
-    raw: Dict[str, list],
-) -> Dict[str, List[torch.Tensor]]:
-    """Convert an accumulated ``{key: [per-record ids]}`` dict to tensors.
-
-    Handles three shapes transparently:
-
-    - ``List[int]`` per record (``sequence``, ``chosen``…) → one tensor per record.
-    - ``List[List[int]]`` per record (GRPO ``responses``/``masks``) → one
-      ``List[Tensor]`` per record (nested), preserving the per-response
-      boundary so downstream code can index responses individually.
-    - ``List[int]`` for the whole shard (pre-packed keys) → single tensor.
-
-    The detection mirrors the previous inline logic in
-    ``Pipeline._flush`` and ``TokenizeTransform.apply``.
-    """
-    tensors: Dict[str, List[torch.Tensor]] = {}
-    for key, ids_list in raw.items():
-        if ids_list and isinstance(ids_list[0], list):
-            tensors[key] = [
-                [torch.tensor(sub, dtype=infer_dtype(sub)) for sub in ids]
-                if ids and isinstance(ids[0], list)
-                else torch.tensor(ids, dtype=infer_dtype(ids))
-                for ids in ids_list
-            ]
-        else:
-            tensors[key] = [
-                torch.tensor(list(chain.from_iterable(ids_list)), dtype=torch.int32)
-            ]
-    return tensors
-
-
-def build_position_ids(
-    sequences: List[List[int]],
-    strategy,
-) -> Optional[List[int]]:
-    """Generate position ids for *sequences* using *strategy*.
-
-    Returns ``None`` when the strategy produces no ids (e.g. ``none``
-    mode), so callers can skip attaching the key instead of storing
-    an empty list.
-    """
-    pos_ids = strategy.generate(sequences)
-    return pos_ids or None
@@ -1,176 +0,0 @@
-"""Sequence packing strategies for shard-level reordering and truncation.
-
-Each strategy receives the accumulated ``{key: [list of token lists]}``
-dict for a shard and returns a reordered / truncated version.  The
-pipeline later flattens the result into contiguous tensors.
-"""
-
-from abc import ABC, abstractmethod
-from typing import Dict, List
-
-from astrai.factory import BaseFactory
-
-
-def _truncate(seq: List[int], max_len: int, mode: str) -> List[int]:
-    if len(seq) <= max_len:
-        return seq
-    if mode == "keep_end":
-        return seq[-max_len:]
-    return seq[:max_len]
-
-
-def plan_bfd(
-    sequences: List[List[int]], max_packed_len: int, truncation_mode: str = "keep_start"
-) -> List[List[int]]:
-    """Best-Fit Decreasing bin packing of *sequences* into bins.
-
-    Returns a list of bins, each bin a list of original indices into
-    *sequences*.  Bin capacities are respected on the *truncated*
-    length of each sequence (so a sequence longer than
-    *max_packed_len* counts at *max_packed_len*).
-
-    Pure index-based so callers can apply the same plan to any
-    aligned key (``loss_mask``, ``position_ids``…).
-    """
-    n = len(sequences)
-    order = sorted(range(n), key=lambda i: len(sequences[i]), reverse=True)
-    bins: List[List[int]] = []
-    bin_lengths: List[int] = []
-
-    for orig_idx in order:
-        seq_len = len(_truncate(sequences[orig_idx], max_packed_len, truncation_mode))
-        best_bin = None
-        best_remain = max_packed_len + 1
-        for i, bl in enumerate(bin_lengths):
-            remain = max_packed_len - bl
-            if seq_len <= remain < best_remain:
-                best_remain = remain
-                best_bin = i
-        if best_bin is not None:
-            bins[best_bin].append(orig_idx)
-            bin_lengths[best_bin] += seq_len
-        else:
-            bins.append([orig_idx])
-            bin_lengths.append(seq_len)
-
-    return bins
-
-
-class PackingStrategy(ABC):
-    """Reorder and truncate sequences within a shard."""
-
-    @abstractmethod
-    def apply(
-        self,
-        keys: Dict[str, List[List[int]]],
-        max_packed_len: int,
-        truncation_mode: str,
-    ) -> Dict[str, List[List[int]]]:
-        raise NotImplementedError
-
-
-class PackingStrategyFactory(BaseFactory["PackingStrategy"]):
-    pass
-
-
-@PackingStrategyFactory.register("simple")
-class SimplePacking(PackingStrategy):
-    def apply(
-        self,
-        keys: Dict[str, List[List[int]]],
-        max_packed_len: int,
-        truncation_mode: str,
-    ) -> Dict[str, List[List[int]]]:
-        return {
-            k: [_truncate(v, max_packed_len, truncation_mode) for v in vals]
-            for k, vals in keys.items()
-        }
-
-
-@PackingStrategyFactory.register("bfd")
-class BFDPacking(PackingStrategy):
-    """Best-Fit Decreasing bin packing.
-
-    Assigns sequences to bins using a best-fit heuristic (sorted by
-    decreasing length) and concatenates sequences within each bin into
-    a single packed sequence.  Packed sequences are truncated to
-    *max_packed_len* so that each packed bin fits within one context
-    window during training.
-    """
-
-    def apply(
-        self,
-        keys: Dict[str, List[List[int]]],
-        max_packed_len: int,
-        truncation_mode: str,
-    ) -> Dict[str, List[List[int]]]:
-        sequences = keys.get("sequence", [])
-        if not sequences:
-            return keys
-        bins = plan_bfd(sequences, max_packed_len, truncation_mode)
-
-        packed: Dict[str, List[List[int]]] = {}
-        for k, vals in keys.items():
-            packed[k] = [
-                _truncate(
-                    self._concat_bin(vals, bin_indices),
-                    max_packed_len,
-                    truncation_mode,
-                )
-                for bin_indices in bins
-            ]
-        return packed
-
-    @staticmethod
-    def _concat_bin(vals: List[List[int]], indices: List[int]) -> List[int]:
-        result: List[int] = []
-        for i in indices:
-            result.extend(vals[i])
-        return result
-
-
-@PackingStrategyFactory.register("bfd_split")
-class BFDSplitPacking(BFDPacking):
-    """BFD packing with over-length sequences split into chunks.
-
-    Sequences longer than *max_packed_len* are split into consecutive
-    chunks of at most *max_packed_len* tokens instead of being
-    truncated.  Each chunk becomes an independent sequence that enters
-    BFD planning.  All keys (``loss_mask``, ``position_ids``, …) are
-    split in lockstep so per-token alignment is preserved.
-
-    Note: because each chunk is treated as a separate document, the
-    second chunk of a split sequence loses the preceding context.
-    """
-
-    def apply(
-        self,
-        keys: Dict[str, List[List[int]]],
-        max_packed_len: int,
-        truncation_mode: str,
-    ) -> Dict[str, List[List[int]]]:
-        sequences = keys.get("sequence", [])
-        if not sequences:
-            return keys
-        if max_packed_len <= 0:
-            return super().apply(keys, max_packed_len, truncation_mode)
-
-        split_keys = self._split_all(keys, max_packed_len)
-        return super().apply(split_keys, max_packed_len, truncation_mode)
-
-    @staticmethod
-    def _split_all(
-        keys: Dict[str, List[List[int]]], max_packed_len: int
-    ) -> Dict[str, List[List[int]]]:
-        """Split every sequence exceeding *max_packed_len* into chunks,
-        applying the same chunk boundaries to all keys."""
-        sequences = keys["sequence"]
-        chunk_bounds = [list(range(0, len(s), max_packed_len)) for s in sequences]
-        result: Dict[str, List[List[int]]] = {}
-        for key, vals in keys.items():
-            split_vals: List[List[int]] = []
-            for val, starts in zip(vals, chunk_bounds):
-                for start in starts:
-                    split_vals.append(val[start : start + max_packed_len])
-            result[key] = split_vals
-        return result
@@ -1,277 +0,0 @@
-"""Config-driven JSONL preprocessing pipeline.
-
-Composes a :class:`BaseMaskBuilder` (selected by ``input.type``) with
-sharding and flush to ``.h5`` / ``.bin`` storage.  Packing, position-id
-generation and storage writing are each delegated to pluggable strategies,
-dispatched by configuration keys.
-
-Record iteration, mask building, primary-id extraction and per-key
-accumulation are shared with :class:`TokenizeTransform` via the
-:mod:`astrai.preprocessing.core` helpers.
-"""
-
-import json
-import logging
-import os
-from collections import defaultdict
-from itertools import chain
-from typing import Dict, List, Optional
-
-import torch
-import tqdm
-
-from astrai.config.preprocess_config import PipelineConfig
-from astrai.preprocessing.core import (
-    build_preprocessing_components,
-    primary_ids,
-)
-from astrai.preprocessing.packing import PackingStrategyFactory
-from astrai.preprocessing.writer import StoreWriterFactory
-
-logger = logging.getLogger(__name__)
-
-_STR_TO_DTYPE: dict[str, torch.dtype] = {
-    "bool": torch.bool,
-    "uint8": torch.uint8,
-    "int8": torch.int8,
-    "int16": torch.int16,
-    "int32": torch.int32,
-    "int64": torch.int64,
-    "float16": torch.float16,
-    "float32": torch.float32,
-    "float64": torch.float64,
-}
-
-
-def filter_by_length(text: str, min_len: int = 50, max_len: int = 2_000_000) -> bool:
-    return min_len <= len(text) <= max_len
-
-
-class Pipeline:
-    """Tokenization pipeline driven by a declarative :class:`PipelineConfig`.
-
-    Usage::
-
-        config = PipelineConfig.from_file("sft_pipeline.json")
-        Pipeline(config, ["data.jsonl"], output_dir="out", tokenizer_path="params").run()
-    """
-
-    def __init__(
-        self,
-        config: PipelineConfig,
-        input_paths: list[str],
-        output_dir: str,
-        tokenizer_path: str,
-    ):
-        os.makedirs(output_dir, exist_ok=True)
-        self.config = config
-        self.paths = input_paths
-        self.output_dir = output_dir
-        self.tokenizer_path = tokenizer_path
-
-        self.tokenizer, self.mask_builder, self._position_id = (
-            build_preprocessing_components(config, tokenizer_path)
-        )
-        self._packer = PackingStrategyFactory.create(
-            config.preprocessing.packing_strategy
-        )
-        self._writer = StoreWriterFactory.create(config.output.storage_format)
-
-    def transform(self, item: dict) -> Optional[dict]:
-        return self.mask_builder.build(item, self.config, self.tokenizer)
-
-    def transform_batch(self, items: list[dict]) -> list[Optional[dict]]:
-        return self.mask_builder.build_batch(items, self.config, self.tokenizer)
-
-    def run(self):
-        domains: dict = defaultdict(lambda: defaultdict(list))
-        total_tokens = 0
-        shard_idx: dict[str, int] = defaultdict(int)
-        count = 0
-
-        pp = self.config.preprocessing
-
-        progress = tqdm.tqdm(desc="Tokenizing", unit="docs", mininterval=0.5)
-        stop = False
-        for items in self._iter_batches(pp.batch_size):
-            progress.update(len(items))
-            try:
-                results = self.transform_batch(items)
-            except Exception:
-                logger.warning(
-                    "Failed to process batch, retrying records individually",
-                    exc_info=True,
-                )
-                results = []
-                for item in items:
-                    try:
-                        results.append(self.transform(item))
-                    except Exception:
-                        logger.warning(
-                            "Failed to process item, skipping", exc_info=True
-                        )
-                        results.append(None)
-
-            for result in results:
-                if pp.max_items and count >= pp.max_items:
-                    stop = True
-                    break
-                if result is None:
-                    continue
-
-                domain = result.pop("domain", "__default__")
-                ids = primary_ids(result)
-                if not ids:
-                    continue
-
-                bucket = domains[domain]
-                self._align_bucket(bucket, result, ids)
-                for key, val in result.items():
-                    bucket[key].append(val)
-
-                count += 1
-                total_tokens += len(ids)
-
-                if total_tokens >= self.config.output.max_tokens_per_shard:
-                    self._flush(domains, shard_idx)
-                    domains.clear()
-                    total_tokens = 0
-            if stop:
-                break
-
-        progress.close()
-
-        if total_tokens > 0:
-            self._flush(domains, shard_idx)
-
-    @staticmethod
-    def _align_bucket(bucket: dict, result: dict, ids: list):
-        """Pad previously-accumulated keys that are missing from *result*."""
-        for key in list(bucket.keys()):
-            if key in result:
-                continue
-            bucket[key].append([0] * len(ids))
-
-    def _iter_items(self):
-        for path in self.paths:
-            with open(path, "r", encoding="utf-8") as f:
-                if path.endswith(".json"):
-                    data = json.load(f)
-                    if isinstance(data, dict):
-                        yield data
-                    elif isinstance(data, list):
-                        yield from data
-                else:
-                    for line in f:
-                        line = line.strip()
-                        if not line:
-                            continue
-                        yield json.loads(line)
-
-    def _iter_batches(self, batch_size: int):
-        batch_size = max(1, batch_size)
-        batch = []
-        for item in self._iter_items():
-            batch.append(item)
-            if len(batch) >= batch_size:
-                yield batch
-                batch = []
-        if batch:
-            yield batch
-
-    def _flush(self, domains, shard_idx):
-        for domain, keys in domains.items():
-            idx = shard_idx[domain]
-
-            pp = self.config.preprocessing
-            original_sequences = keys.get("sequence", [])
-            mode = self.config.output.position_ids_mode
-
-            keys = self._inject_doc_reset_position_ids(keys, mode, original_sequences)
-            keys = self._packer.apply(dict(keys), pp.max_packed_len, pp.truncation_mode)
-            tensors = self._to_tensors(keys)
-            tensors = self._inject_continuous_position_ids(
-                tensors, mode, keys.get("sequence", [])
-            )
-
-            self._writer.save(self.output_dir, domain, idx, tensors)
-            shard_idx[domain] = idx + 1
-
-            first_key = "sequence" if "sequence" in tensors else next(iter(tensors))
-            tqdm.tqdm.write(
-                f"  saved {domain}/shard_{idx:04d}  "
-                f"({tensors[first_key][0].numel():,} tokens)"
-            )
-
-    def _inject_doc_reset_position_ids(
-        self,
-        keys: Dict[str, list],
-        mode: str,
-        original_sequences: List[List[int]],
-    ) -> Dict[str, list]:
-        """Attach per-document position_ids before packing (``doc_reset``).
-
-        ``doc_reset`` position ids must enter the packer so that each
-        packed bin concatenates the per-doc ranges in bin order.  The
-        per-record structure ``[range(len(s)) for s in seqs]`` is required
-        by the packer (it concatenates per-record lists per bin); the
-        ``PositionIdStrategy.generate`` flattens, so it cannot be used
-        directly here — it is only consulted for the ``continuous``
-        post-packing path.
-        """
-        if mode != "doc_reset" or not original_sequences:
-            return keys
-        keys["position_ids"] = [list(range(len(s))) for s in original_sequences]
-        return keys
-
-    def _inject_continuous_position_ids(
-        self,
-        tensors: Dict[str, List[torch.Tensor]],
-        mode: str,
-        packed_sequences: List[List[int]],
-    ) -> Dict[str, List[torch.Tensor]]:
-        """Attach a single continuous position_ids tensor after packing.
-
-        ``continuous`` mode spans the whole shard (post-packing), so it
-        cannot participate in bin packing — it is computed from the
-        packed sequences and appended directly to the tensor dict.
-        """
-        if mode != "continuous" or not packed_sequences:
-            return tensors
-        pos_ids = self._position_id.generate(packed_sequences)
-        if pos_ids:
-            tensors["position_ids"] = [torch.tensor(pos_ids, dtype=torch.int32)]
-        return tensors
-
-    def _to_tensors(self, keys: Dict[str, list]) -> Dict[str, List[torch.Tensor]]:
-        """Convert packed per-key id lists to tensors.
-
-        Honours ``config.output.dtype`` overrides per key; falls back to
-        ``int32``.  Handles three shapes (see
-        :func:`astrai.preprocessing.core.to_per_record_tensors` for the
-        equivalent online-path helper):
-        - ``List[int]`` per record → one tensor per record.
-        - ``List[List[int]]`` per record (GRPO responses/masks) → one tensor
-          per record, inner lists flattened.
-        - ``List[int]`` for the whole shard (pre-packed keys) → single tensor.
-        """
-        tensors: Dict[str, List[torch.Tensor]] = {}
-        for key, ids_list in keys.items():
-            dt = _STR_TO_DTYPE.get(
-                self.config.output.dtype.get(key, "int32"), torch.int32
-            )
-            if ids_list and isinstance(ids_list[0], list):
-                tensors[key] = [
-                    torch.tensor(
-                        list(chain.from_iterable(ids))
-                        if ids and isinstance(ids[0], list)
-                        else ids,
-                        dtype=dt,
-                    )
-                    for ids in ids_list
-                ]
-            else:
-                tensors[key] = [
-                    torch.tensor(list(chain.from_iterable(ids_list)), dtype=dt)
-                ]
-        return tensors
@@ -1,46 +0,0 @@
-"""Position-id generation strategies for packed sequences.
-
-Each strategy takes the list of per-document token sequences after packing
-and returns a flat list of position ids (same total length as all
-sequences combined).  The pipeline wraps the result into a tensor and
-attaches it as ``position_ids``.
-"""
-
-from abc import ABC, abstractmethod
-from typing import List
-
-from astrai.factory import BaseFactory
-
-
-class PositionIdStrategy(ABC):
-    """Generate ``position_ids`` for packed sequences."""
-
-    @abstractmethod
-    def generate(self, sequences: List[List[int]]) -> List[int]:
-        raise NotImplementedError
-
-
-class PositionIdStrategyFactory(BaseFactory["PositionIdStrategy"]):
-    pass
-
-
-@PositionIdStrategyFactory.register("none")
-class NoPositionId(PositionIdStrategy):
-    def generate(self, sequences: List[List[int]]) -> List[int]:
-        return []
-
-
-@PositionIdStrategyFactory.register("doc_reset")
-class DocResetPositionId(PositionIdStrategy):
-    def generate(self, sequences: List[List[int]]) -> List[int]:
-        pos_ids = []
-        for seq in sequences:
-            pos_ids.extend(range(len(seq)))
-        return pos_ids
-
-
-@PositionIdStrategyFactory.register("continuous")
-class ContinuousPositionId(PositionIdStrategy):
-    def generate(self, sequences: List[List[int]]) -> List[int]:
-        total = sum(len(seq) for seq in sequences)
-        return list(range(total))
@@ -1,92 +0,0 @@
-"""Tokenization transform for JSONL record streams.
-
-Bridges the Reader layer (``JsonlStore`` reads raw JSON records) and the
-Dataset layer (expects per-record tensors).  Holds the tokenizer,
-mask-builder and position-id strategy together so that I/O code stays
-free of model dependencies.
-
-The record-processing core (mask building, primary-id extraction,
-per-key tensorisation, position-id generation) is shared with
-:class:`astrai.preprocessing.pipeline.Pipeline` via the
-:mod:`astrai.preprocessing.core` helpers.
-"""
-
-import json
-from pathlib import Path
-from typing import Dict, List
-
-import torch
-
-from astrai.config.preprocess_config import PipelineConfig
-from astrai.preprocessing.core import (
-    build_position_ids,
-    build_preprocessing_components,
-    iter_raw_records,
-    to_per_record_tensors,
-)
-
-
-class TokenizeTransform:
-    """Tokenize raw JSONL record dicts into per-key tensor lists.
-
-    Owns the three preprocessing concerns that were previously inlined in
-    ``JsonlStore``: tokenization, loss-mask construction and position-id
-    generation.  Constructing it loads the tokenizer, so it is intentionally
-    cheap to pass around once built.
-
-    Args:
-        config: Pipeline config describing sections / masks / position mode.
-        tokenizer_path: Path passed to ``AutoTokenizer.from_pretrained``.
-    """
-
-    def __init__(self, config: PipelineConfig, tokenizer_path: str):
-        self.config = config
-        self.tokenizer, self.mask_builder, self.position_strategy = (
-            build_preprocessing_components(config, tokenizer_path)
-        )
-
-    @classmethod
-    def from_config_file(cls, config_path: str) -> "TokenizeTransform":
-        """Build from a ``dataset_config.json`` file path.
-
-        The config file follows :class:`PipelineConfig` schema with an
-        extra ``tokenizer_path`` field.  When omitted, the config's
-        parent directory is used as the tokenizer path.
-        """
-        root = Path(config_path).parent
-        with open(config_path, "r", encoding="utf-8") as f:
-            raw_config = json.load(f)
-        tokenizer_path = raw_config.pop("tokenizer_path", None) or str(root)
-        config = PipelineConfig.from_dict(raw_config)
-        return cls(config, tokenizer_path)
-
-    def apply(self, records: List[dict]) -> Dict[str, list]:
-        """Tokenize a list of raw record dicts.
-
-        Returns a dict mapping key (``sequence``, ``chosen``, ``responses``,
-        …) to a list of per-record tensors (or nested tensor lists for
-        multi-response keys such as GRPO ``responses``).
-        """
-        raw: Dict[str, list] = {}
-        doc_sequences: List[List[int]] = []
-
-        for result in iter_raw_records(
-            records, self.mask_builder, self.config, self.tokenizer
-        ):
-            primary = None
-            for val in result.values():
-                if isinstance(val, list) and val and isinstance(val[0], int):
-                    primary = val
-                    break
-            if primary is not None:
-                doc_sequences.append(primary)
-            for key, ids in result.items():
-                raw.setdefault(key, []).append(ids)
-
-        tensors = to_per_record_tensors(raw)
-
-        pos_ids = build_position_ids(doc_sequences, self.position_strategy)
-        if pos_ids is not None:
-            tensors["position_ids"] = [torch.tensor(pos_ids, dtype=torch.int32)]
-
-        return tensors
@@ -1,75 +0,0 @@
-"""Storage writer strategies for pipeline output.
-
-The :class:`StoreWriter` abstraction decouples the pipeline from the
-concrete storage format (bin / h5).  The pipeline builds a ``{key:
-List[Tensor]}`` dict and delegates the write to the writer selected
-by ``output.storage_format``.
-"""
-
-import logging
-import os
-import shutil
-from abc import ABC, abstractmethod
-from typing import Dict, List
-
-import torch
-
-from astrai.factory import BaseFactory
-from astrai.serialization import save_bin, save_h5
-
-logger = logging.getLogger(__name__)
-
-
-class StoreWriter(ABC):
-    """Write pre-tokenized tensors to disk in a format-specific way."""
-
-    @abstractmethod
-    def save(
-        self,
-        output_dir: str,
-        domain: str,
-        shard_idx: int,
-        tensors: Dict[str, List[torch.Tensor]],
-    ) -> None: ...
-
-
-class StoreWriterFactory(BaseFactory["StoreWriter"]):
-    pass
-
-
-@StoreWriterFactory.register("bin")
-class BinWriter(StoreWriter):
-    def save(self, output_dir, domain, shard_idx, tensors):
-        shard_path = os.path.join(output_dir, domain, f"shard_{shard_idx:04d}")
-        try:
-            save_bin(shard_path, tensors)
-        except Exception:
-            if os.path.exists(shard_path):
-                shutil.rmtree(shard_path, ignore_errors=True)
-            logger.error(
-                "Failed to write shard %s/%s_%04d, cleaned up partial output",
-                domain,
-                "shard",
-                shard_idx,
-                exc_info=True,
-            )
-            raise
-
-
-@StoreWriterFactory.register("h5")
-class H5Writer(StoreWriter):
-    def save(self, output_dir, domain, shard_idx, tensors):
-        chunk_dir = os.path.join(output_dir, domain)
-        file_path = os.path.join(chunk_dir, f"data_{shard_idx:04d}.h5")
-        try:
-            save_h5(chunk_dir, f"data_{shard_idx:04d}", tensors)
-        except Exception:
-            if os.path.exists(file_path):
-                os.remove(file_path)
-            logger.error(
-                "Failed to write shard %s/data_%04d.h5, cleaned up partial output",
-                domain,
-                shard_idx,
-                exc_info=True,
-            )
-            raise
@@ -0,0 +1,83 @@
+import json
+import time
+from pathlib import Path
+from typing import Any, Dict, Optional
+
+import safetensors.torch as st
+import torch
+import torch.distributed as dist
+
+from astrai.parallel.setup import get_rank
+
+
+class Checkpoint:
+    def __init__(
+        self,
+        state_dict: Dict[str, Any],
+        epoch: int = 0,
+        iteration: int = 0,
+        extra: Optional[Dict[str, Any]] = None,
+        meta: Optional[Dict[str, Any]] = None,
+    ):
+        self.state_dict = state_dict
+        self.epoch = epoch
+        self.iteration = iteration
+        self.extra = extra or {}
+        self.meta = meta or {}
+
+    def save(
+        self,
+        save_dir: str,
+    ) -> None:
+
+        save_path = Path(save_dir)
+        save_path.mkdir(parents=True, exist_ok=True)
+
+        rank = get_rank()
+        if rank == 0:
+            meta = {
+                "epoch": self.epoch,
+                "iteration": self.iteration,
+                "timestamp": time.strftime("%Y-%m-%dT%H:%M:%S"),
+            }
+            meta.update(self.meta)
+            with open(save_path / "meta.json", "w") as f:
+                json.dump(meta, f, indent=2)
+
+            st.save_file(self.state_dict, save_path / "state_dict.safetensors")
+            if self.extra:
+                for key, value in self.extra.items():
+                    torch.save(value, save_path / f"{key}.pt")
+
+    @classmethod
+    def load(
+        cls,
+        save_dir: str,
+    ) -> "Checkpoint":
+
+        rank = get_rank()
+        save_path = Path(save_dir)
+
+        meta = {}
+        if rank == 0:
+            with open(Path(save_dir) / "meta.json", "r") as f:
+                meta = json.load(f)
+
+        if dist.is_initialized():
+            meta_list = [meta]
+            dist.broadcast_object_list(meta_list, src=0)
+            meta = meta_list[0]
+
+        state_dict = st.load_file(save_path / "state_dict.safetensors")
+
+        extra = {}
+        for f in save_path.iterdir():
+            if f.suffix == ".pt" and f.stem not in ("meta",):
+                extra[f.stem] = torch.load(f, map_location="cpu", weights_only=False)
+
+        return cls(
+            state_dict=state_dict,
+            epoch=meta["epoch"],
+            iteration=meta["iteration"],
+            extra=extra or None,
+        )
@@ -1,45 +0,0 @@
-"""Serialization utilities for models and datasets.
-
-This package re-exports checkpoint helpers and dataset storage helpers so
-that existing imports from ``astrai.serialization`` continue to work.
-"""
-
-from astrai.serialization.checkpoint import (
-    Checkpoint,
-    load_json,
-    load_model_config,
-    load_model_weights,
-    load_safetensors,
-    load_state_dict,
-    load_torch,
-    save_json,
-    save_model,
-    save_safetensors,
-    save_torch,
-)
-from astrai.serialization.dataset import (
-    load_bin,
-    load_bin_offsets,
-    load_h5,
-    save_bin,
-    save_h5,
-)
-
-__all__ = [
-    "Checkpoint",
-    "load_json",
-    "load_model_config",
-    "load_model_weights",
-    "load_safetensors",
-    "load_state_dict",
-    "load_torch",
-    "save_json",
-    "save_model",
-    "save_safetensors",
-    "save_torch",
-    "load_bin",
-    "load_bin_offsets",
-    "load_h5",
-    "save_bin",
-    "save_h5",
-]
@@ -1,201 +0,0 @@
-"""Model checkpoint serialization helpers."""
-
-import io
-import json
-import time
-from dataclasses import dataclass, field
-from pathlib import Path
-from typing import Any, Dict, Optional, Union
-
-import safetensors.torch as st
-import torch
-import torch.distributed as dist
-
-from astrai.parallel.setup import get_rank
-
-_META_FILE = "meta.json"
-_CONFIG_FILE = "config.json"
-_WEIGHTS_FILE = "model.safetensors"
-
-
-def save_safetensors(state_dict: dict, path: Union[str, Path]):
-    st.save_file(state_dict, str(path))
-
-
-def load_safetensors(path: Union[str, Path], broadcast: bool = False) -> dict:
-    if not broadcast or not dist.is_initialized():
-        return st.load_file(str(path))
-
-    rank = get_rank()
-    if rank == 0:
-        state_dict = st.load_file(str(path))
-    else:
-        state_dict = {}
-    tmp = [state_dict]
-    dist.broadcast_object_list(tmp, src=0)
-    return tmp[0]
-
-
-def save_json(data: dict, path: Union[str, Path]):
-    with open(str(path), "w") as f:
-        json.dump(data, f, indent=2)
-
-
-def load_json(path: Union[str, Path], broadcast: bool = False) -> dict:
-    if not broadcast or not dist.is_initialized():
-        with open(str(path), "r") as f:
-            return json.load(f)
-
-    rank = get_rank()
-    if rank == 0:
-        with open(str(path), "r") as f:
-            data = json.load(f)
-    else:
-        data = {}
-    tmp = [data]
-    dist.broadcast_object_list(tmp, src=0)
-    return tmp[0]
-
-
-def save_torch(obj: Any, path: Union[str, Path]):
-    torch.save(obj, str(path))
-
-
-def load_torch(path: Union[str, Path], broadcast: bool = False) -> Any:
-    if not broadcast or not dist.is_initialized():
-        return torch.load(str(path), map_location="cpu", weights_only=False)
-
-    path = Path(path)
-    rank = get_rank()
-
-    if rank == 0:
-        with open(path, "rb") as f:
-            raw = f.read()
-        data_tensor = torch.frombuffer(bytearray(raw), dtype=torch.uint8)
-        num_bytes = torch.tensor([len(raw)], dtype=torch.long)
-    else:
-        num_bytes = torch.tensor([0], dtype=torch.long)
-
-    dist.broadcast(num_bytes, src=0)
-
-    if rank != 0:
-        data_tensor = torch.empty(num_bytes.item(), dtype=torch.uint8)
-
-    dist.broadcast(data_tensor, src=0)
-
-    buf = io.BytesIO(data_tensor.numpy().tobytes())
-    return torch.load(buf, map_location="cpu", weights_only=False)
-
-
-def save_model(config: dict, state_dict: dict, save_directory: str):
-    save_path = Path(save_directory)
-    save_path.mkdir(parents=True, exist_ok=True)
-    save_json(config, save_path / _CONFIG_FILE)
-    save_safetensors(state_dict, save_path / _WEIGHTS_FILE)
-
-
-def load_model_config(save_directory: str) -> dict:
-    return load_json(Path(save_directory) / _CONFIG_FILE)
-
-
-def load_model_weights(save_directory: str) -> dict:
-    return load_state_dict(Path(save_directory) / _WEIGHTS_FILE)
-
-
-def load_state_dict(path: Union[str, Path], broadcast: bool = False) -> dict:
-    path = Path(path)
-    if not broadcast or not dist.is_initialized():
-        return load_safetensors(path)
-
-    rank = get_rank()
-    if rank == 0:
-        state_dict = load_safetensors(path)
-        specs = [
-            (k, list(state_dict[k].shape), str(state_dict[k].dtype).split(".")[-1])
-            for k in sorted(state_dict)
-        ]
-    else:
-        state_dict = {}
-        specs = []
-
-    specs_list = [specs]
-    dist.broadcast_object_list(specs_list, src=0)
-    specs = specs_list[0]
-
-    for key, shape, dtype_name in specs:
-        dtype = getattr(torch, dtype_name)
-        if rank != 0:
-            tensor = torch.empty(shape, dtype=dtype, device="cpu")
-        else:
-            tensor = state_dict[key].contiguous().cpu()
-        dist.broadcast(tensor, src=0)
-        if rank != 0:
-            state_dict[key] = tensor
-    return state_dict
-
-
-@dataclass
-class Checkpoint:
-    state_dict: Dict[str, Any] = field(default_factory=dict)
-    epoch: int = 0
-    consumed_samples: int = 0
-    extra: Dict[str, Any] = field(default_factory=dict)
-    meta: Dict[str, Any] = field(default_factory=dict)
-    config: Dict[str, Any] = field(default_factory=dict)
-
-    def save(self, save_dir: str):
-        save_path = Path(save_dir)
-        save_path.mkdir(parents=True, exist_ok=True)
-
-        meta = {
-            "epoch": self.epoch,
-            "consumed_samples": self.consumed_samples,
-            "timestamp": time.strftime("%Y-%m-%dT%H:%M:%S"),
-            **self.meta,
-        }
-        save_json(meta, save_path / _META_FILE)
-        save_json(self.config, save_path / _CONFIG_FILE)
-        save_safetensors(self.state_dict, save_path / _WEIGHTS_FILE)
-        for key, value in self.extra.items():
-            save_torch(value, save_path / f"{key}.pt")
-
-    @classmethod
-    def load(cls, save_dir: str, broadcast: bool = False) -> "Checkpoint":
-        save_path = Path(save_dir)
-
-        meta = load_json(save_path / _META_FILE, broadcast)
-        config = load_json(save_path / _CONFIG_FILE, broadcast)
-        state_dict = load_state_dict(save_path / _WEIGHTS_FILE, broadcast=broadcast)
-
-        extra = {}
-        for f in sorted(save_path.iterdir()):
-            if f.suffix == ".pt":
-                extra[f.stem] = load_torch(f, broadcast=broadcast)
-
-        return cls(
-            state_dict=state_dict,
-            epoch=meta.get("epoch", 0),
-            consumed_samples=meta.get("consumed_samples", 0),
-            extra=extra,
-            meta=meta,
-            config=config,
-        )
-
-    @classmethod
-    def load_any(cls, save_dir: str, broadcast: bool = False) -> Optional["Checkpoint"]:
-        save_path = Path(save_dir)
-        meta_path = save_path / _META_FILE
-        weights_path = save_path / _WEIGHTS_FILE
-
-        if meta_path.exists():
-            return cls.load(save_dir, broadcast=broadcast)
-
-        if weights_path.exists():
-            state_dict = load_state_dict(weights_path, broadcast=broadcast)
-            config = {}
-            config_path = save_path / _CONFIG_FILE
-            if config_path.exists():
-                config = load_json(config_path, broadcast)
-            return cls(state_dict=state_dict, config=config)
-
-        return None
@@ -1,123 +0,0 @@
-"""Dataset storage serialization helpers (HDF5 / memory-mapped binary)."""
-
-import json
-import os
-from pathlib import Path
-from typing import Any, Dict, List, Optional
-
-import h5py
-import numpy as np
-import torch
-from torch import Tensor
-
-
-def save_h5(file_path: str, file_name: str, tensor_group: Dict[str, List[Tensor]]):
-    os.makedirs(file_path, exist_ok=True)
-    full_file_path = os.path.join(file_path, f"{file_name}.h5")
-    with h5py.File(full_file_path, "w") as f:
-        for key, tensors in tensor_group.items():
-            grp = f.create_group(key)
-            for idx, tensor in enumerate(tensors):
-                arr = tensor.cpu().numpy()
-                grp.create_dataset(f"data_{idx}", data=arr)
-
-
-def load_h5(file_path: str, share_memory=True) -> Dict[str, List[Tensor]]:
-    tensor_group: Dict[str, List[Tensor]] = {}
-
-    root_path = Path(file_path)
-    if root_path.is_file() and root_path.suffix in (".h5", ".hdf5"):
-        h5_files = [root_path]
-    else:
-        h5_files = list(root_path.rglob("*.h5")) + list(root_path.rglob("*.hdf5"))
-
-    for h5_file in h5_files:
-        with h5py.File(h5_file, "r") as f:
-            for key in f.keys():
-                grp = f[key]
-                dsets = []
-                for dset_name in grp.keys():
-                    dset = grp[dset_name]
-                    tensor = torch.from_numpy(dset[:])
-                    if share_memory:
-                        tensor = tensor.share_memory_()
-                    dsets.append(tensor)
-
-                if tensor_group.get(key) is None:
-                    tensor_group[key] = []
-                tensor_group[key].extend(dsets)
-
-    return tensor_group
-
-
-def save_bin(
-    file_path: str,
-    tensor_group: Dict[str, List[Tensor]],
-    record_keys: Optional[List[str]] = None,
-):
-    """Save tensors as memory-mapped binary files.
-
-    When *record_keys* is provided, those keys are written with per-record
-    cumulative offsets in ``meta.json`` so that ``MmapStore.fetch_record``
-    can slice individual records from the concatenated binary without
-    cross-record concatenation.  Keys not in *record_keys* (e.g. SEQ
-    ``sequence``) are written as a single contiguous stream without
-    offsets, preserving backward compatibility.
-
-    Nested keys (``List[List[Tensor]]`` such as GRPO ``responses``) are
-    not supported in bin format — use H5 for those.
-    """
-    os.makedirs(file_path, exist_ok=True)
-    record_keys = set(record_keys or [])
-    meta = {}
-    for key, tensors in tensor_group.items():
-        if tensors and isinstance(tensors[0], list):
-            raise ValueError(
-                f"Nested key '{key}' (List[List[Tensor]]) is not supported "
-                f"in bin format. Use H5 or JSONL storage instead."
-            )
-        cat = torch.cat(tensors, dim=0)
-        entry: Dict[str, Any] = {
-            "shape": list(cat.shape),
-            "dtype": str(cat.dtype).split(".")[-1],
-        }
-        if key in record_keys:
-            offsets = [0]
-            for t in tensors:
-                offsets.append(offsets[-1] + t.shape[0])
-            entry["offsets"] = offsets
-        meta[key] = entry
-        np.asarray(cat.cpu().numpy()).tofile(os.path.join(file_path, f"{key}.bin"))
-    with open(os.path.join(file_path, "meta.json"), "w") as f:
-        json.dump(meta, f)
-
-
-def load_bin(file_path: str) -> Dict[str, List[Tensor]]:
-    with open(os.path.join(file_path, "meta.json"), "r") as f:
-        meta = json.load(f)
-    segments: Dict[str, List[Tensor]] = {}
-    for key, info in meta.items():
-        arr = np.memmap(
-            os.path.join(file_path, f"{key}.bin"),
-            dtype=info["dtype"],
-            mode="c",
-            shape=tuple(info["shape"]),
-        )
-        segments[key] = [torch.from_numpy(arr)]
-    return segments
-
-
-def load_bin_offsets(file_path: str) -> Dict[str, List[int]]:
-    """Read per-record cumulative offsets from ``meta.json``.
-
-    Returns an empty dict when no key has offsets (legacy bin files),
-    in which case record-mode access falls back to per-record segment
-    indexing (H5/JSONL layout).
-    """
-    with open(os.path.join(file_path, "meta.json"), "r") as f:
-        meta = json.load(f)
-    offsets: Dict[str, List[int]] = {}
-    for key, info in meta.items():
-        if "offsets" in info:
-            offsets[key] = info["offsets"]
-    return offsets
@@ -1,10 +1,8 @@
 from astrai.tokenize.chat_template import ChatTemplate, MessageType
-from astrai.tokenize.tokenizer import AutoTokenizer, Message, Messages
+from astrai.tokenize.tokenizer import AutoTokenizer

 __all__ = [
    "AutoTokenizer",
    "ChatTemplate",
    "MessageType",
-    "Message",
-    "Messages",
 ]
@@ -1,11 +1,13 @@
-from functools import cached_property
+from dataclasses import dataclass
 from typing import Any, Dict, List, Optional

 from jinja2 import Template

+# Message type for chat messages
 type MessageType = Dict[str, Any]


+@dataclass
 class ChatTemplate:
    """A chat template with Jinja2 rendering support.

@@ -13,36 +15,23 @@ class ChatTemplate:
        name: Unique identifier for the template.
        template_str: Jinja2 template string.
        description: Optional description.
-        default_variables: Optional dictionary of default variable values.
+        default_variables: Optional dictionary of default variable values
+            that will be passed to the template if not overridden during rendering.
        special_tokens: Optional dictionary mapping token names to their string values.
+            These tokens are automatically added to the template variables.
    """

-    def __init__(
-        self,
-        name: str = "",
-        template_str: str = "",
-        description: str = "",
-        default_variables: Optional[Dict[str, Any]] = None,
-        special_tokens: Optional[Dict[str, str]] = None,
-    ):
-        self.name = name
-        self.template_str = template_str
-        self.description = description
-        self.default_variables = default_variables or {}
-        self.special_tokens = special_tokens or {}
+    name: str
+    template_str: str
+    description: str = ""
+    default_variables: Dict[str, Any] = None
+    special_tokens: Dict[str, str] = None

-    @cached_property
-    def _compiled(self) -> Template:
-        """Lazy-compiled Jinja2 template, cached on first access.
-
-        The compiled :class:`~jinja2.Template` holds a dynamically-generated
-        ``root`` render function whose ``__module__`` is ``None``; under
-        ``pickle`` it falls back to ``__main__`` and breaks ``spawn``-based
-        multiprocessing.  By deferring compilation to first access, the
-        default pickle protocol serialises only ``template_str``; each
-        worker rebuilds the cache on first render.
-        """
-        return Template(self.template_str)
+    def __post_init__(self):
+        if self.default_variables is None:
+            self.default_variables = {}
+        if self.special_tokens is None:
+            self.special_tokens = {}

    @classmethod
    def from_string(
@@ -54,7 +43,7 @@ class ChatTemplate:
    ) -> "ChatTemplate":
        """Create a ChatTemplate instance directly from a template string."""
        return cls(
-            name="",
+            name="",  # empty name for ad‑hoc templates
            template_str=template_str,
            description=description,
            default_variables=default_variables,
@@ -84,4 +73,5 @@ class ChatTemplate:
        if system_prompt is not None:
            variables["system_prompt"] = system_prompt

-        return self._compiled.render(**variables)
+        jinja_template = Template(self.template_str)
+        return jinja_template.render(**variables)
@@ -10,12 +10,6 @@ from tokenizers import Tokenizer

 from astrai.tokenize.chat_template import ChatTemplate

-Message = Dict[str, str]
-"""Single chat message with ``role`` and ``content`` keys."""
-
-Messages = List[Message]
-"""Single conversation — a list of messages."""
-

 class AutoTokenizer:
    """Base tokenizer class with automatic loading support"""
@@ -126,16 +120,7 @@ class AutoTokenizer:
        is_pretokenized: bool = False,
        add_special_tokens: bool = True,
    ) -> List:
-        """Encode text to token IDs.
-
-        Accepts both single strings and batches:
-
-        - ``encode("hello")`` → ``[123, 456]``
-        - ``encode(["hello", "world"])`` → ``[[123, 456], [789]]``
-
-        Batches are tokenised in parallel via the Rust backend's
-        ``encode_batch`` (uses all available CPU cores).
-        """
+        """Encode text to tokens or token IDs."""
        if self._tokenizer is None:
            raise RuntimeError(
                "Tokenizer not initialized. Load or create a tokenizer first."
@@ -148,13 +133,15 @@ class AutoTokenizer:
                add_special_tokens=add_special_tokens,
            )
            return encoded.ids if out_ids else encoded.tokens
-
-        encoded_list = self._tokenizer.encode_batch(
-            tokens,
-            is_pretokenized=is_pretokenized,
-            add_special_tokens=add_special_tokens,
-        )
-        return [encoded.ids if out_ids else encoded.tokens for encoded in encoded_list]
+        else:
+            encoded_list = self._tokenizer.encode_batch(
+                tokens,
+                is_pretokenized=is_pretokenized,
+                add_special_tokens=add_special_tokens,
+            )
+            return [
+                encoded.ids if out_ids else encoded.tokens for encoded in encoded_list
+            ]

    def decode(self, tokens: List[int], skip_special_tokens: bool = True) -> str:
        """Decode token IDs to text."""
@@ -177,14 +164,7 @@ class AutoTokenizer:
          - tokenizer.bos_token   → returns string
          - tokenizer.bos_token_id → returns corresponding integer ID
          - tokenizer.stop_ids → returns list of corresponding integer IDs for all special tokens
-
-        Internal/private attrs are not intercepted: during unpickle
-        ``__dict__`` is empty, so probing ``self._special_token_map``
-        would recurse infinitely.
        """
-        if key.startswith("_"):
-            raise AttributeError(key)
-
        # Handle stop_ids - return IDs for all special tokens
        if key == "stop_ids":
            stop_ids = []
@@ -240,63 +220,45 @@ class AutoTokenizer:

    def apply_chat_template(
        self,
-        messages: Union[Messages, List[Messages]],
+        messages: List[Dict[str, str]],
        system_prompt: Optional[str] = None,
        tokenize: bool = True,
        add_generation_prompt: bool = True,
        **kwargs,
-    ) -> Union[str, List[int], List[str], List[List[int]]]:
-        """Apply the chat template and optionally tokenize.
-
-        Accepts both single conversations and batches:
-
-        - ``apply_chat_template([msg1, msg2])`` → ``"..."`` or ``[ids]``
-        - ``apply_chat_template([[msg1, msg2], [msg3]])`` → ``["..", ".."]``
-          or ``[[ids], [ids]]``
-
-        Batches render each conversation list and tokenise all at once via
-        :meth:`encode` (``List[str]`` → Rust parallel ``encode_batch``).
+    ) -> Union[str, List[int]]:
+        """
+        Apply the chat template to messages and optionally tokenize the result.

        Args:
-            messages: Single conversation (``Messages``) or batch of
-                conversations (``BatchMessages``).
-            system_prompt: Optional system prompt prepended (single mode only).
+            messages: List of message dicts with 'role' and 'content'.
+            system_prompt: Optional system prompt string (auto-converted to first message).
            tokenize: Whether to return token IDs (True) or raw string (False).
-            add_generation_prompt: Whether to add the generation prompt.
-            **kwargs: Additional template variables.
+            add_generation_prompt: Whether to add the generation prompt (default: True).
+            **kwargs: Additional variables to pass to the template.

        Returns:
-            Single mode: ``str`` or ``List[int]``.
-            Batch mode: ``List[str]`` or ``List[List[int]]``.
+            Either the rendered string or list of token IDs.
+
+        Raises:
+            RuntimeError: If chat template is not set.
        """
        if self._chat_template is None:
            raise RuntimeError(
                "Chat template not set. Use set_chat_template() to set a template first."
            )

-        is_batch = bool(messages) and isinstance(messages[0], list)
-
-        if is_batch:
-            rendered = [
-                self._chat_template.render(
-                    messages=msgs,
-                    add_generation_prompt=add_generation_prompt,
-                    **kwargs,
-                )
-                for msgs in messages
-            ]
-            if tokenize:
-                return self.encode(rendered)  # List[str] → batch encode
-            return rendered
-
-        # Single conversation
+        # Auto-convert system_prompt to first message if provided
        if system_prompt:
            messages = [{"role": "system", "content": system_prompt}] + list(messages)
+
+        # Render the template
        rendered = self._chat_template.render(
            messages=messages,
            add_generation_prompt=add_generation_prompt,
            **kwargs,
        )
+
        if tokenize:
            return self.encode(rendered)
+
        return rendered
@@ -1,3 +1,4 @@
+from astrai.trainer.optim import Muon
 from astrai.trainer.schedule import BaseScheduler, SchedulerFactory
 from astrai.trainer.strategy import BaseStrategy, StrategyFactory
 from astrai.trainer.train_callback import (
@@ -9,6 +10,8 @@ from astrai.trainer.trainer import Trainer
 __all__ = [
    # Main trainer
    "Trainer",
+    # Optimizer
+    "Muon",
    # Strategy factory
    "StrategyFactory",
    "BaseStrategy",
@@ -1,25 +1,42 @@
-from typing import Dict
+from typing import Any, Callable, Dict

 import torch
 import torch.nn as nn


-def grad_norm(model: nn.Module, per_param: bool = False) -> float | Dict[str, float]:
-    grads = [p.grad.detach() for p in model.parameters() if p.grad is not None]
-    if not grads:
-        return 0.0
+def _grad_stat(
+    model: nn.Module, fn: Callable[[torch.Tensor], Any], default: Any
+) -> dict:
+    results = {}
+    for name, param in model.named_parameters():
+        results[name] = default
+        if param.grad is not None:
+            results[name] = fn(param.grad.data)
+    return results

-    total_sq = torch.stack([g.pow(2).sum() for g in grads]).sum()
-    if per_param:
-        norms = {}
-        for name, param in model.named_parameters():
-            if param.grad is not None:
-                norms[name] = param.grad.norm(2).item()
-            else:
-                norms[name] = 0.0
-        norms["total"] = total_sq.sqrt().item()
-        return norms
-    return total_sq.sqrt().item()
+
+def grad_norm(model: nn.Module, norm_type: int = 2) -> Dict[str, float]:
+    return _grad_stat(model, lambda g: g.norm(norm_type).item(), 0.0)
+
+
+def grad_std(model: nn.Module) -> Dict[str, float]:
+    return _grad_stat(model, lambda g: g.std().item(), 0.0)
+
+
+def grad_max(model: nn.Module) -> Dict[str, float]:
+    return _grad_stat(model, lambda g: g.max().item(), -float("inf"))
+
+
+def grad_min(model: nn.Module) -> Dict[str, float]:
+    return _grad_stat(model, lambda g: g.min().item(), float("inf"))
+
+
+def grad_mean(model: nn.Module) -> Dict[str, float]:
+    return _grad_stat(model, lambda g: g.mean().item(), 0.0)
+
+
+def grad_nan_num(model: nn.Module) -> Dict[str, int]:
+    return _grad_stat(model, lambda g: g.isnan().sum().item(), 0)


 def ctx_get_loss(ctx):
@@ -35,4 +52,24 @@ def ctx_get_val_loss(ctx):


 def ctx_get_grad_norm(ctx):
-    return ctx.grad_norm
+    return grad_norm(ctx.model)
+
+
+def ctx_get_grad_std(ctx):
+    return grad_std(ctx.model)
+
+
+def ctx_get_grad_max(ctx):
+    return grad_max(ctx.model)
+
+
+def ctx_get_grad_min(ctx):
+    return grad_min(ctx.model)
+
+
+def ctx_get_grad_mean(ctx):
+    return grad_mean(ctx.model)
+
+
+def ctx_get_grad_nan_num(ctx):
+    return grad_nan_num(ctx.model)
@@ -0,0 +1,143 @@
+import torch
+from torch.optim import Optimizer
+
+
+def _zeropower_via_newtonschulz(G: torch.Tensor, steps: int = 5):
+    assert G.ndim == 2
+    X = G
+    scale = max(1, G.size(0) / G.size(1)) ** 0.5
+    X = X / (X.norm() + 1e-7) * scale
+    if steps == 0:
+        return X
+    a, b, c = (3.4445, -4.7750, 2.0315)
+    for _ in range(steps):
+        A = X @ X.T
+        B = A @ X
+        X = a * X + b * B + c * (A @ B)
+    return X
+
+
+class Muon(Optimizer):
+    def __init__(
+        self,
+        params,
+        lr: float = 2e-3,
+        momentum: float = 0.95,
+        weight_decay: float = 0.0,
+        nesterov: bool = True,
+        ns_steps: int = 5,
+        adamw_lr: float = None,
+        adamw_betas: tuple = (0.9, 0.95),
+        adamw_eps: float = 1e-8,
+        adamw_wd: float = 0.0,
+    ):
+        defaults = dict(
+            lr=lr,
+            momentum=momentum,
+            weight_decay=weight_decay,
+            nesterov=nesterov,
+            ns_steps=ns_steps,
+            adamw_lr=adamw_lr if adamw_lr is not None else lr * 0.1,
+            adamw_betas=adamw_betas,
+            adamw_eps=adamw_eps,
+            adamw_wd=adamw_wd,
+        )
+        super().__init__(params, defaults)
+
+    @torch.no_grad()
+    def step(self, closure=None):
+        loss = None
+        if closure is not None:
+            with torch.enable_grad():
+                loss = closure()
+
+        for group in self.param_groups:
+            params_2d, params_1d = [], []
+            grads_2d, grads_1d = [], []
+
+            for p in group["params"]:
+                if p.grad is None:
+                    continue
+                if p.grad.is_sparse:
+                    raise RuntimeError("Muon does not support sparse gradients")
+                if p.ndim >= 2:
+                    params_2d.append(p)
+                    grads_2d.append(p.grad)
+                else:
+                    params_1d.append(p)
+                    grads_1d.append(p.grad)
+
+            if params_2d:
+                self._muon_update_foreach(params_2d, grads_2d, group)
+            if params_1d:
+                self._adamw_update_foreach(params_1d, grads_1d, group)
+
+        return loss
+
+    def _muon_update_foreach(self, params_2d, grads_2d, group):
+        lr = group["lr"]
+        momentum = group["momentum"]
+        wd = group["weight_decay"]
+        nesterov = group["nesterov"]
+        ns_steps = group["ns_steps"]
+
+        if wd != 0:
+            torch._foreach_mul_(params_2d, 1 - lr * wd)
+
+        if nesterov:
+            grads_2d = torch._foreach_add(grads_2d, params_2d, alpha=wd)
+
+        bufs = []
+        for p, grad in zip(params_2d, grads_2d):
+            state = self.state[p]
+            if "momentum_buffer" not in state:
+                state["momentum_buffer"] = torch.zeros_like(grad)
+            bufs.append(state["momentum_buffer"])
+
+        torch._foreach_lerp_(bufs, grads_2d, 1 - momentum)
+
+        for p, buf in zip(params_2d, bufs):
+            update = _zeropower_via_newtonschulz(buf, steps=ns_steps)
+            scale = max(1, p.size(0) / p.size(1)) ** 0.5
+            p.add_(update, alpha=-lr * scale)
+
+    def _adamw_update_foreach(self, params_1d, grads_1d, group):
+        lr = group["adamw_lr"]
+        betas = group["adamw_betas"]
+        eps = group["adamw_eps"]
+        wd = group["adamw_wd"]
+
+        steps: list[int] = []
+        exp_avgs, exp_avg_sqs = [], []
+        has_state = []
+        for p in params_1d:
+            state = self.state[p]
+            if not state:
+                state["step"] = 0
+                state["exp_avg"] = torch.zeros_like(p)
+                state["exp_avg_sq"] = torch.zeros_like(p)
+                has_state.append(False)
+            else:
+                has_state.append(True)
+            state["step"] += 1
+            steps.append(state["step"])
+            exp_avgs.append(state["exp_avg"])
+            exp_avg_sqs.append(state["exp_avg_sq"])
+
+        beta1, beta2 = betas
+
+        torch._foreach_lerp_(exp_avgs, grads_1d, 1 - beta1)
+        grads_sq = torch._foreach_mul(grads_1d, grads_1d)
+        torch._foreach_lerp_(exp_avg_sqs, grads_sq, 1 - beta2)
+
+        bias_correction1 = [1 - beta1**s for s in steps]
+        bias_correction2 = [1 - beta2**s for s in steps]
+
+        if wd != 0:
+            torch._foreach_mul_(params_1d, 1 - lr * wd)
+
+        exp_avg_corrected = torch._foreach_div(exp_avgs, bias_correction1)
+        denom = torch._foreach_div(exp_avg_sqs, bias_correction2)
+        denom = torch._foreach_sqrt(denom)
+        torch._foreach_add_(denom, eps)
+        torch._foreach_addcdiv_(params_1d, exp_avg_corrected, denom, value=-lr)
@@ -1,421 +0,0 @@
-"""Online rollout runner for RL training.
-
-Provides:
- :class:`RawRollout` — generation output container (no reward yet)
- :class:`RolloutResult` — a :class:`RawRollout` with rewards attached
- :class:`BaseRewardModel` — pluggable reward interface
- :class:`RolloutGenerator` — KV-cache-backed generation of grouped
-  responses + decoding (no reward); delegates the generation loop to
-  :class:`~astrai.inference.core.scheduler.InferenceScheduler.run_batch`
-  so rollout and the production inference server share one code path
- :class:`RolloutRunner` — orchestrates generation + scoring with a
-  step-driven cache; its ``__call__`` returns ``(RolloutResult, is_fresh)``
-  so callers do not need to rely on object identity to detect refreshes.
-"""
-
-from abc import ABC, abstractmethod
-from dataclasses import dataclass, field
-from typing import Dict, List, Optional, Tuple
-
-import torch
-from torch import Tensor
-
-from astrai.inference.core.scheduler import InferenceScheduler
-
-
-@dataclass(kw_only=True)
-class RawRollout:
-    """Generation output before reward scoring.
-
-    Produced by :class:`RolloutGenerator`; consumed by :class:`RolloutRunner`
-    to assemble a :class:`RolloutResult` once rewards are attached.
-
-    Fields are designed to cover all common RL algorithms:
-    GRPO, PPO, Online DPO, Rejection Sampling, etc.
-
-    Fields:
-        prompts: Tokenized prompts, shape ``[B, P_len]``.
-        prompt_mask: Boolean mask for real prompt tokens, shape ``[B, P_len]``.
-        responses: Generated response token IDs, shape ``[B, G, R_max]``.
-        response_mask: Boolean mask for real (non-pad) response tokens,
-            shape ``[B, G, R_max]``.
-        logprobs_old: Per-token log-probs under the behaviour policy,
-            shape ``[B, G, R_max]``.
-        prompt_texts: Decoded prompt strings (for reward models that
-            need text).
-        response_texts: Decoded response strings, shape ``[B, G]``
-            (for reward models).
-    """
-
-    prompts: Tensor
-    prompt_mask: Tensor
-    responses: Tensor
-    response_mask: Tensor
-    logprobs_old: Tensor
-    prompt_texts: List[str] = field(default_factory=list)
-    response_texts: List[List[str]] = field(default_factory=list)
-
-
-@dataclass(kw_only=True)
-class RolloutResult(RawRollout):
-    """A :class:`RawRollout` with reward scoring attached.
-
-    Produced by :class:`RolloutRunner` once the :class:`BaseRewardModel`
-    has scored the decoded responses.
-
-    Fields:
-        rewards: Reward per response, shape ``[B, G]``.
-    """
-
-    rewards: Tensor
-
-
-class BaseRewardModel(ABC):
-    """Pluggable reward model interface.
-
-    Subclasses should implement ``score()`` to return a ``[B, G]`` float
-    tensor of rewards.  Implementations can be:
-    * A loaded reward model (e.g. ArmoRM, Skywork-Reward)
-    * An external API call
-    * A rule-based function (format, length, keyword matching)
-    """
-
-    @abstractmethod
-    def score(self, prompts: List[str], responses: List[List[str]]) -> Tensor:
-        """Score each generated response.
-
-        Args:
-            prompts: Raw prompt strings, length ``B``.
-            responses: Generated response strings, shape ``[B, G]``.
-
-        Returns:
-            Float tensor of shape ``[B, G]``.
-        """
-        ...
-
-
-_PAD = 0
-
-
-class RolloutGenerator:
-    """Pure generation + decoding for a group of responses per prompt.
-
-    Delegates the prefill/decode loop to
-    :meth:`~astrai.inference.core.scheduler.InferenceScheduler.run_batch`,
-    which uses a real KV cache (no O(n²) recompute).  Has no dependency
-    on any reward model; can be reused in isolation for offline
-    generation, qualitative sampling, or eval pipelines.
-    """
-
-    def __init__(
-        self,
-        scheduler: InferenceScheduler,
-        tokenizer,
-        max_tokens: int = 1024,
-        group_size: int = 8,
-        temperature: float = 1.0,
-        top_k: int = 0,
-        top_p: float = 1.0,
-        frequency_penalty: float = 0.0,
-        rep_window: int = 64,
-    ):
-        self.scheduler = scheduler
-        self.tokenizer = tokenizer
-        self.max_tokens = max_tokens
-        self.group_size = group_size
-        self.temperature = temperature
-        self.top_k = top_k
-        self.top_p = top_p
-        self.frequency_penalty = frequency_penalty
-        self.rep_window = rep_window
-
-    @torch.no_grad()
-    def generate(self, batch: Dict) -> RawRollout:
-        """Expand prompts by ``group_size`` and generate one response each.
-
-        Accepted batch formats (per sample, repeated B times):
-
-        - **messages**: ``{"messages": [{"role": "user", "content": "..."}, ...]}``
-        - **instruction + input + output**: ``{"instruction": "...",
-          "input": "...", "output": "..."}`` — mapped to ``system`` /
-          ``user`` / ``assistant`` messages; ``input`` and ``output``
-          are optional and skipped when empty.
-
-        Both are rendered through the tokenizer's chat template with
-        ``add_generation_prompt=True`` so rollout prompts match the
-        format the policy was SFT-trained on.
-        """
-        model = self.scheduler._executor.model
-        was_training = model.training
-        model.eval()
-        try:
-            return self._generate_eval(batch)
-        finally:
-            model.train(was_training)
-
-    def _generate_eval(self, batch: Dict) -> RawRollout:
-        prompt_texts, flat_prompt_ids = self._prepare_prompts(batch)
-        B = len(prompt_texts)
-        G = self.group_size
-        # Re-expand flat list to G copies per prompt for run_batch.
-        expanded_prompt_ids: List[List[int]] = []
-        for ids in flat_prompt_ids:
-            expanded_prompt_ids.extend([list(ids)] * G)
-
-        results = self.scheduler.run_batch(
-            expanded_prompt_ids,
-            max_tokens=self.max_tokens,
-            temperature=self.temperature,
-            top_k=self.top_k,
-            top_p=self.top_p,
-            frequency_penalty=self.frequency_penalty,
-            rep_window=self.rep_window,
-            return_logprobs=True,
-        )
-        if len(results) != B * G:
-            raise RuntimeError(
-                f"Rollout scheduler returned {len(results)} results, expected {B * G}"
-            )
-        for token_ids, logprobs in results:
-            if len(token_ids) != len(logprobs):
-                raise RuntimeError(
-                    "Rollout scheduler returned misaligned token IDs and logprobs"
-                )
-
-        # Each element is (token_ids, logprobs); pad to max length.
-        max_len = 0
-        for token_ids, _lp in results:
-            max_len = max(max_len, len(token_ids))
-        max_len = max(max_len, 1)
-
-        device = self.scheduler.device
-        P_len = max(len(ids) for ids in flat_prompt_ids)
-        prompts_tensor = torch.zeros(B, P_len, dtype=torch.long, device=device)
-        prompt_mask = torch.zeros(B, P_len, dtype=torch.bool, device=device)
-        for i, ids in enumerate(flat_prompt_ids):
-            prompts_tensor[i, -len(ids) :] = torch.tensor(
-                ids, dtype=torch.long, device=device
-            )
-            prompt_mask[i, -len(ids) :] = True
-
-        responses = torch.full((B, G, max_len), _PAD, dtype=torch.long, device=device)
-        response_mask = torch.zeros((B, G, max_len), dtype=torch.bool, device=device)
-        logprobs_old = torch.zeros((B, G, max_len), dtype=torch.float, device=device)
-
-        flat_idx = 0
-        response_texts: List[List[str]] = [[] for _ in range(B)]
-        for i in range(B):
-            for g in range(G):
-                token_ids, lps = results[flat_idx]
-                flat_idx += 1
-                n = len(token_ids)
-                if n:
-                    responses[i, g, :n] = torch.tensor(
-                        token_ids, dtype=torch.long, device=device
-                    )
-                    response_mask[i, g, :n] = True
-                    logprobs_old[i, g, :n] = torch.tensor(
-                        lps, dtype=torch.float, device=device
-                    )
-                response_texts[i].append(
-                    self.tokenizer.decode(token_ids, skip_special_tokens=True)
-                )
-
-        return RawRollout(
-            prompts=prompts_tensor,
-            prompt_mask=prompt_mask,
-            responses=responses,
-            response_mask=response_mask,
-            logprobs_old=logprobs_old,
-            prompt_texts=prompt_texts,
-            response_texts=response_texts,
-        )
-
-    def _prepare_prompts(self, batch: Dict) -> Tuple[List[str], List[List[int]]]:
-        """Render batch prompts to ``(texts, token_id_lists)``.
-
-        Returns two parallel lists of length B (number of prompts in
-        the batch).  Dispatches by batch keys:
-
-        - ``"messages"``: treated as a pre-built message list per sample.
-        - ``"instruction"`` (optionally ``"input"`` and ``"output"``): mapped
-          to ``system`` / ``user`` / ``assistant`` messages respectively.
-
-        Both paths go through the tokenizer's chat template with
-        ``add_generation_prompt=True``.
-        """
-        if "messages" in batch:
-            messages_list = batch["messages"]
-        elif "instruction" in batch:
-            instructions = batch["instruction"]
-            B = len(instructions)
-            inputs = batch.get("input") or [""] * B
-            outputs = batch.get("output") or [""] * B
-            messages_list = [
-                self._instruction_to_messages(i, u, o)
-                for i, u, o in zip(instructions, inputs, outputs)
-            ]
-        else:
-            raise ValueError(
-                "Rollout batch must contain either 'messages' or "
-                "'instruction' (optionally 'input'/'output'); got keys: "
-                f"{list(batch.keys())}"
-            )
-
-        try:
-            prompt_texts = self.tokenizer.apply_chat_template(
-                messages_list, tokenize=False, add_generation_prompt=True
-            )
-            if (
-                not isinstance(prompt_texts, list)
-                or len(prompt_texts) != len(messages_list)
-                or not all(isinstance(text, str) for text in prompt_texts)
-            ):
-                raise TypeError("Tokenizer does not support batched chat templates")
-            flat_prompt_ids = self.tokenizer.encode(prompt_texts)
-            if len(flat_prompt_ids) != len(messages_list) or not all(
-                isinstance(ids, list) for ids in flat_prompt_ids
-            ):
-                raise TypeError("Tokenizer does not support batched encoding")
-        except (TypeError, IndexError, KeyError):
-            # Keep compatibility with lightweight tokenizer adapters that only
-            # implement the single-conversation template API.
-            prompt_texts = []
-            flat_prompt_ids = []
-            for messages in messages_list:
-                text = self.tokenizer.apply_chat_template(
-                    messages, tokenize=False, add_generation_prompt=True
-                )
-                ids = self.tokenizer.apply_chat_template(
-                    messages, tokenize=True, add_generation_prompt=True
-                )
-                prompt_texts.append(text)
-                flat_prompt_ids.append(list(ids))
-        return prompt_texts, flat_prompt_ids
-
-    @staticmethod
-    def _instruction_to_messages(
-        instruction: str, inp: str = "", output: str = ""
-    ) -> List[Dict[str, str]]:
-        """Map instruction/input/output to chat messages.
-
-        Role mapping follows the convention used throughout the
-        preprocessing pipeline: ``instruction`` → system, ``input`` →
-        user, ``output`` → assistant.  Empty fields are skipped so a
-        bare instruction produces a ``[system]`` list and the chat
-        template's ``add_generation_prompt`` adds the assistant header
-        for sampling.
-        """
-        messages: List[Dict[str, str]] = []
-        if instruction:
-            messages.append({"role": "system", "content": instruction})
-        if inp:
-            messages.append({"role": "user", "content": inp})
-        if output:
-            messages.append({"role": "assistant", "content": output})
-        return messages
-
-
-class RolloutRunner:
-    """Produces :class:`RolloutResult` from a prompt batch.
-
-    Composes a :class:`RolloutGenerator` (generation + decoding) with a
-    :class:`BaseRewardModel` (scoring).  Maintains an internal cache so
-    the same batch prompt can be replayed for multiple gradient steps.
-    A new rollout is triggered every ``rollout_interval`` calls to
-    :meth:`step` (or after :meth:`clear_cache`).
-
-    The ``__call__`` contract returns a ``(RolloutResult, is_fresh)``
-    tuple — callers must use the boolean to detect a refreshed rollout
-    rather than relying on object identity.
-
-    Usage::
-
-        generator = RolloutGenerator(policy, tokenizer, pipeline, ...)
-        runner = RolloutRunner(generator, reward_model, rollout_interval=512)
-        result, is_fresh = runner(prompt_batch)
-        if is_fresh:
-            ...  # e.g. sync behaviour policy
-    """
-
-    def __init__(
-        self,
-        generator: RolloutGenerator,
-        reward_model: BaseRewardModel,
-        rollout_interval: int = 512,
-    ):
-        self.generator = generator
-        self.reward_model = reward_model
-        self.rollout_interval = rollout_interval
-
-        self._cache: Optional[RolloutResult] = None
-        self._cache_key = None
-        self._steps_since_rollout: int = 0
-
-    def step(self):
-        """Advance the internal counter (call once per optimizer step)."""
-        self._steps_since_rollout += 1
-
-    def clear_cache(self):
-        """Force next call to re-run rollout."""
-        self._cache = None
-        self._cache_key = None
-
-    @staticmethod
-    def _batch_key(batch: Dict):
-        """Build a stable key for the prompt fields accepted by the generator."""
-
-        def freeze(value):
-            if isinstance(value, dict):
-                return tuple(sorted((key, freeze(val)) for key, val in value.items()))
-            if isinstance(value, (list, tuple)):
-                return tuple(freeze(item) for item in value)
-            return value
-
-        fields = ("messages", "instruction", "input", "output")
-        return tuple(
-            (field, freeze(batch[field])) for field in fields if field in batch
-        )
-
-    def _score(self, raw: RawRollout) -> RolloutResult:
-        rewards = self.reward_model.score(raw.prompt_texts, raw.response_texts)
-        if not isinstance(rewards, Tensor):
-            rewards = torch.as_tensor(rewards, dtype=torch.float32)
-        expected_shape = raw.responses.shape[:2]
-        if rewards.shape != expected_shape:
-            raise ValueError(
-                f"Reward model returned shape {tuple(rewards.shape)}, "
-                f"expected {tuple(expected_shape)}"
-            )
-        if not torch.isfinite(rewards).all():
-            raise ValueError("Reward model returned non-finite values")
-        device = raw.prompts.device
-        return RolloutResult(
-            prompts=raw.prompts,
-            prompt_mask=raw.prompt_mask,
-            responses=raw.responses,
-            response_mask=raw.response_mask,
-            rewards=rewards.to(device=device),
-            logprobs_old=raw.logprobs_old,
-            prompt_texts=raw.prompt_texts,
-            response_texts=raw.response_texts,
-        )
-
-    def __call__(self, batch: Dict[str, Tensor]) -> Tuple[RolloutResult, bool]:
-        """Return ``(cached or fresh) RolloutResult`` plus an ``is_fresh`` flag.
-
-        Triggers a new rollout when ``_steps_since_rollout >= rollout_interval``
-        or when the cache is empty.
-        """
-        cache_key = self._batch_key(batch)
-        if (
-            self._cache is None
-            or cache_key != self._cache_key
-            or self._steps_since_rollout >= self.rollout_interval
-        ):
-            raw = self.generator.generate(batch)
-            self._cache = self._score(raw)
-            self._cache_key = cache_key
-            self._steps_since_rollout = 0
-            return self._cache, True
-        return self._cache, False
@@ -2,7 +2,7 @@

 import math
 from abc import ABC, abstractmethod
-from typing import Any, Dict, List
+from typing import Any, Dict, List, Type

 from torch.optim.lr_scheduler import LRScheduler

@@ -31,6 +31,7 @@ class SchedulerFactory(BaseFactory["BaseScheduler"]):
    """Factory class for creating learning rate schedulers.

    Supports decorator-based registration for extensible scheduler types.
+    Also supports creation from ScheduleConfig objects.

    Example usage:
        @SchedulerFactory.register("custom")
@@ -40,6 +41,33 @@ class SchedulerFactory(BaseFactory["BaseScheduler"]):
        scheduler = SchedulerFactory.create("custom", optimizer, **kwargs)
    """

+    @classmethod
+    def _validate_component(cls, scheduler_cls: Type[BaseScheduler]) -> None:
+        """Validate that the scheduler class inherits from BaseScheduler."""
+        if not issubclass(scheduler_cls, BaseScheduler):
+            raise TypeError(f"{scheduler_cls.__name__} must inherit from BaseScheduler")
+
+    @classmethod
+    def create(
+        cls, optimizer, schedule_type: str = "none", **kwargs
+    ) -> "BaseScheduler":
+        """Create a scheduler instance by type name.
+
+        Args:
+            optimizer: PyTorch optimizer
+            schedule_type: Type of scheduler ("cosine", "sgdr")
+            **kwargs: Arguments passed to the scheduler constructor
+
+        Returns:
+            Scheduler instance
+        """
+        return super().create(schedule_type, optimizer, **kwargs)
+
+    @classmethod
+    def available_types(cls) -> list:
+        """Return list of registered scheduler type names."""
+        return cls.list_registered()
+

 # ----------- Scheduler implementations -----------

@@ -53,7 +81,7 @@ class CosineScheduler(BaseScheduler):
        optimizer,
        warmup_steps: int,
        lr_decay_steps: int,
-        min_rate: float = 0.01,
+        min_rate: float = 0.05,
        last_epoch: int = -1,
    ):
        self.warmup_steps = warmup_steps
@@ -65,15 +93,11 @@ class CosineScheduler(BaseScheduler):
    def get_lr(self) -> List[float]:
        # warmup
        if self.last_epoch < self.warmup_steps:
-            warmup_factor = max(
-                self.min_rate, self.last_epoch / max(self.warmup_steps, 1)
-            )
+            warmup_factor = max(self.min_rate, self.last_epoch / self.warmup_steps)
            return [base_lr * warmup_factor for base_lr in self.base_lrs]

        # cosine decay
-        decay_progress = (self.last_epoch - self.warmup_steps) / max(
-            self.lr_decay_steps, 1
-        )
+        decay_progress = (self.last_epoch - self.warmup_steps) / self.lr_decay_steps
        decay_progress = min(decay_progress, 1.0)
        cosine_decay = 0.5 * (1.0 + math.cos(math.pi * decay_progress))
        decay_factor = max(self.min_rate, cosine_decay)
@@ -108,7 +132,7 @@ class SGDRScheduler(BaseScheduler):
        optimizer,
        warmup_steps: int,
        cycle_length: int,
-        min_rate: float = 0.01,
+        min_rate: float = 0.05,
        t_mult: int = 2,
        last_epoch: int = -1,
    ):
@@ -122,9 +146,7 @@ class SGDRScheduler(BaseScheduler):
    def get_lr(self):
        # warmup
        if self.last_epoch < self.warmup_steps:
-            warmup_factor = max(
-                self.min_rate, self.last_epoch / max(self.warmup_steps, 1)
-            )
+            warmup_factor = max(self.min_rate, self.last_epoch / self.warmup_steps)
            return [base_lr * warmup_factor for base_lr in self.base_lrs]

        # SGDR
@@ -170,66 +192,3 @@ class SGDRScheduler(BaseScheduler):
        self.min_rate = state_dict.pop("min_rate")
        self.t_mult = state_dict.pop("t_mult")
        super().load_state_dict(state_dict)
-
-
-@SchedulerFactory.register("wsd")
-class WSDScheduler(BaseScheduler):
-    """WSD (Warmup-Stable-Decay) scheduler with sqrt cooldown.
-
-    warmup_steps:  linear warmup from min_rate to 1.0
-    stable_steps:   constant at base_lr
-    decay_steps:    sqrt decay from base_lr to min_rate
-    min_rate:       minimum lr as fraction of base_lr (default 0.0)
-    """
-
-    def __init__(
-        self,
-        optimizer,
-        warmup_steps: int,
-        stable_steps: int,
-        decay_steps: int,
-        min_rate: float = 0.01,
-        last_epoch: int = -1,
-    ):
-        self.warmup_steps = warmup_steps
-        self.stable_steps = stable_steps
-        self.decay_steps = decay_steps
-        self.min_rate = min_rate
-        self.total_steps = warmup_steps + stable_steps + decay_steps
-        super().__init__(optimizer, last_epoch)
-
-    def get_lr(self) -> List[float]:
-        if self.last_epoch < self.warmup_steps:
-            factor = max(self.min_rate, self.last_epoch / max(self.warmup_steps, 1))
-            return [base_lr * factor for base_lr in self.base_lrs]
-
-        offset = self.last_epoch - self.warmup_steps
-
-        if offset < self.stable_steps:
-            return list(self.base_lrs)
-
-        decay_ratio = (offset - self.stable_steps) / max(self.decay_steps, 1)
-        decay_ratio = min(decay_ratio, 1.0)
-        factor = (1.0 - self.min_rate) * (1.0 - decay_ratio) ** 2 + self.min_rate
-        return [base_lr * factor for base_lr in self.base_lrs]
-
-    def state_dict(self):
-        state = super().state_dict()
-        state.update(
-            {
-                "warmup_steps": self.warmup_steps,
-                "stable_steps": self.stable_steps,
-                "decay_steps": self.decay_steps,
-                "min_rate": self.min_rate,
-                "total_steps": self.total_steps,
-            }
-        )
-        return state
-
-    def load_state_dict(self, state_dict):
-        self.warmup_steps = state_dict.pop("warmup_steps")
-        self.stable_steps = state_dict.pop("stable_steps")
-        self.decay_steps = state_dict.pop("decay_steps")
-        self.min_rate = state_dict.pop("min_rate")
-        self.total_steps = state_dict.pop("total_steps")
-        super().load_state_dict(state_dict)
@@ -1,47 +1,57 @@
 """Training strategy implementations with factory pattern."""

+import copy
 from abc import ABC, abstractmethod
-from typing import Callable, Dict, Union
+from typing import Any, Callable, Dict, Union

 import torch
 import torch.nn as nn
 import torch.nn.functional as F
 from torch import Tensor
+from torch.distributed.fsdp import FullyShardedDataParallel as FSDP
+from torch.nn.parallel import DistributedDataParallel as DDP

 from astrai.factory import BaseFactory
-from astrai.trainer.rollout import RolloutResult


-def create_ref_model(
-    model_fn: Callable[[], nn.Module], state_dict: Dict[str, Tensor]
-) -> nn.Module:
-    """Create a frozen reference model from model_fn + full state dict."""
-    ref_model = model_fn()
-    ref_model.load_state_dict(state_dict)
+def unwrap_model(model: nn.Module) -> nn.Module:
+    if isinstance(model, DDP):
+        return model.module
+    if isinstance(model, FSDP):
+        return model._fsdp_wrapped_module
+    return model
+
+
+def create_ref_model(model: nn.Module) -> nn.Module:
+    """Create a reference model for DPO/GRPO training.
+
+    Handles DDP-wrapped models safely by unwrapping first,
+    then creating a deep copy with frozen gradients.
+    """
+    original_model = unwrap_model(model)
+    ref_model = copy.deepcopy(original_model)
    ref_model.requires_grad_(False)
    ref_model.eval()
    return ref_model


-def move_to_device(batch: Dict[str, Tensor], device: str) -> Dict[str, Tensor]:
+def move_to_device(batch: Dict[str, Tensor], device: str) -> Any:
    """Move batch tensors to specified device with non-blocking transfer."""
    return {key: value.to(device, non_blocking=True) for key, value in batch.items()}


 def get_logprobs(
-    model: nn.Module,
+    model: Union[nn.Module, Callable[..., Dict[str, Tensor]]],
    input_ids: Tensor,
-    attn_mask: Tensor,
-    loss_mask: Tensor,
+    mask: Tensor,
    reduction: str,
-) -> Tensor:
+):
    """Compute token-wise log probabilities from model outputs.

    Args:
        model: The language model
        input_ids: Input token IDs of shape [batch_size, seq_len]
-        attn_mask: Attention mask passed to the model (may include causal).
-        loss_mask: Per-token mask for loss reduction.
+        mask: Attention mask of shape [batch_size, seq_len]
        reduction: How to reduce over sequence dimension ("mean", "sum", "none")

    Returns:
@@ -54,12 +64,9 @@ def get_logprobs(
        )

    shifted_input_ids = input_ids[:, 1:]
-    shifted_loss_mask = loss_mask[:, 1:]
+    shifted_mask = mask[:, 1:]

-    logits = model(
-        input_ids[:, :-1],
-        attn_mask[:, :, :-1, :-1] if attn_mask.dim() == 4 else attn_mask[:, :-1],
-    )["logits"]
+    logits = model(input_ids[:, :-1], mask[:, :-1])["logits"]
    log_probs = torch.log_softmax(logits.float(), dim=-1)

    token_logprobs = torch.gather(
@@ -67,53 +74,24 @@ def get_logprobs(
    ).squeeze(-1)

    if reduction == "mean":
-        return (token_logprobs * shifted_loss_mask).sum(dim=-1) / shifted_loss_mask.sum(
+        return (token_logprobs * shifted_mask).sum(dim=-1) / shifted_mask.sum(
            dim=-1
        ).clamp(min=1.0)
    elif reduction == "sum":
-        return (token_logprobs * shifted_loss_mask).sum(dim=-1)
+        return (token_logprobs * shifted_mask).sum(dim=-1)
    else:
-        return token_logprobs * shifted_loss_mask
-
-
-def make_doc_boundary_mask(position_ids: Tensor) -> Tensor:
-    S = position_ids.size(1)
-    device = position_ids.device
-    boundaries = position_ids[:, 1:] <= position_ids[:, :-1]
-    doc_ids = torch.cat(
-        [
-            torch.zeros(position_ids.size(0), 1, dtype=torch.long, device=device),
-            boundaries.long().cumsum(dim=1),
-        ],
-        dim=1,
-    )
-    same_doc = doc_ids.unsqueeze(-1) == doc_ids.unsqueeze(-2)
-    causal = torch.tril(torch.ones(S, S, dtype=torch.bool, device=device))
-    return (same_doc & causal).unsqueeze(1)
+        return token_logprobs * shifted_mask


 class BaseStrategy(ABC):
-    """Abstract base class for training strategies.
-
-    When a :class:`~astrai.trainer.rollout.RolloutRunner` is injected via
-    :meth:`set_rollout_runner`, the strategy transparently switches to
-    online mode: each ``__call__`` produces a :class:`RolloutResult`,
-    converts it to a training batch via :meth:`prepare_from_rollout`, and
-    then computes the loss.  Without a runner the strategy runs in
-    offline mode and consumes the batch directly.
-    """
+    """Abstract base class for training strategies."""

    def __init__(
-        self,
-        model: Union[nn.Module, Callable[..., Dict[str, Tensor]]],
-        device: str,
-        **kwargs,
+        self, model: Union[Callable[..., Dict[str, Tensor]]], device: str, **kwargs
    ):
        self.model = model
        self.device = device
-        self.executor = kwargs.pop("executor", None)
        self.extra_kwargs = kwargs
-        self._rollout_runner = None

    @abstractmethod
    def compute_loss(self, batch: Dict[str, Tensor]) -> Tensor:
@@ -127,53 +105,9 @@ class BaseStrategy(ABC):
        """
        raise NotImplementedError

-    def supports_online(self) -> bool:
-        """Whether this strategy can operate with a rollout runner.
-
-        Base implementation returns ``False``; strategies that implement
-        :meth:`prepare_from_rollout` should override to return ``True``.
-        """
-        return False
-
-    def set_rollout_runner(self, runner):
-        """Inject a :class:`RolloutRunner` to enable online rollout mode."""
-        self._rollout_runner = runner
-
-    def prepare_from_rollout(self, result: RolloutResult) -> Dict[str, Tensor]:
-        """Map a :class:`RolloutResult` to the batch layout expected by
-        :meth:`compute_loss`.
-
-        Strategies that return ``True`` from :meth:`supports_online` must
-        override this.  Default raises :class:`NotImplementedError`.
-        """
-        raise NotImplementedError(
-            f"{type(self).__name__} does not support online rollout"
-        )
-
-    def _on_rollout_refresh(self):
-        """Hook fired when a fresh rollout result is produced.
-
-        Override to refresh stale state (e.g. syncing the behaviour
-        policy).  Default is a no-op.
-        """
-        pass
-
-    def on_optimizer_step(self):
-        """Advance online rollout state after a successful optimizer step."""
-        if self._rollout_runner is not None:
-            self._rollout_runner.step()
-
    def __call__(self, batch: Dict[str, Tensor]) -> Tensor:
-        """Run offline or online forward depending on runner injection."""
-        if self._rollout_runner is None:
-            return self.compute_loss(batch)
-
-        result, is_fresh = self._rollout_runner(batch)
-        if is_fresh:
-            self._on_rollout_refresh()
-
-        train_batch = self.prepare_from_rollout(result)
-        return self.compute_loss(train_batch)
+        """Allow calling strategy directly as a callable."""
+        return self.compute_loss(batch)


 class StrategyFactory(BaseFactory["BaseStrategy"]):
@@ -190,6 +124,32 @@ class StrategyFactory(BaseFactory["BaseStrategy"]):
        strategy = StrategyFactory.create("custom", model, device)
    """

+    @classmethod
+    def _validate_component(cls, strategy_cls: type) -> None:
+        """Validate that the strategy class inherits from BaseStrategy."""
+        if not issubclass(strategy_cls, BaseStrategy):
+            raise TypeError(f"{strategy_cls.__name__} must inherit from BaseStrategy")
+
+    @classmethod
+    def create(cls, train_type: str, model, device: str, **kwargs) -> "BaseStrategy":
+        """Create a strategy instance based on training type.
+
+        Args:
+            train_type: Type of training ("seq", "sft", "dpo", "grpo")
+            model: Model instance for the strategy
+            device: Device to run the strategy on
+            **kwargs: Additional arguments passed to strategy constructor
+
+        Returns:
+            Strategy instance
+        """
+        return super().create(train_type, model, device, **kwargs)
+
+    @classmethod
+    def available_strategies(cls) -> list:
+        """Return list of registered strategy names."""
+        return cls.list_registered()
+

 # ============== Strategy Classes ==============
 # All strategies are registered at class definition time using the decorator
@@ -202,13 +162,7 @@ class SEQStrategy(BaseStrategy):
    Computes cross-entropy loss for next token prediction.
    """

-    def __init__(
-        self,
-        model: Union[nn.Module, Callable[..., Dict[str, Tensor]]],
-        device: str,
-        label_smoothing: float = 0.0,
-        **kwargs,
-    ):
+    def __init__(self, model, device, label_smoothing: float = 0.0, **kwargs):
        super().__init__(model, device, **kwargs)
        self.label_smoothing = label_smoothing

@@ -233,31 +187,21 @@ class SFTStrategy(BaseStrategy):
    Applies cross-entropy loss only to tokens where loss_mask is True.
    """

-    def __init__(
-        self,
-        model: Union[nn.Module, Callable[..., Dict[str, Tensor]]],
-        device: str,
-        label_smoothing: float = 0.0,
-        **kwargs,
-    ):
+    def __init__(self, model, device, label_smoothing: float = 0.0, **kwargs):
        super().__init__(model, device, **kwargs)
        self.label_smoothing = label_smoothing

    def compute_loss(self, batch: Dict[str, Tensor]) -> Tensor:
        batch = move_to_device(batch, self.device)
-        input_ids, target_ids, position_ids, loss_mask = (
+        input_ids, target_ids, loss_mask = (
            batch["input_ids"],
            batch["target_ids"],
-            batch["position_ids"],
            batch["loss_mask"],
        )

        ignore_index = -100
-        input_mask = make_doc_boundary_mask(position_ids)
-        target_ids = target_ids.masked_fill(~loss_mask, ignore_index)
-        logits = self.model(
-            input_ids=input_ids, position_ids=position_ids, input_mask=input_mask
-        )["logits"]
+        logits = self.model(input_ids=input_ids)["logits"]
+        target_ids = target_ids.masked_fill(loss_mask == 0, ignore_index)

        loss = F.cross_entropy(
            input=logits.flatten(0, 1).float(),
@@ -281,13 +225,12 @@ class DPOStrategy(BaseStrategy):
        self,
        model: nn.Module,
        device: str,
-        ref_model: nn.Module,
        beta: float = 0.1,
-        reduction: str = "sum",
+        reduction: str = "mean",
        **kwargs,
    ):
        super().__init__(model, device, **kwargs)
-        self.ref_model = ref_model
+        self.ref_model = create_ref_model(model)
        self.beta = beta
        self.reduction = reduction

@@ -297,31 +240,13 @@ class DPOStrategy(BaseStrategy):
        chosen_mask, rejected_mask = batch["chosen_mask"], batch["rejected_mask"]

        concat_ids = torch.cat([chosen_ids, rejected_ids], dim=0)
-        concat_loss_mask = torch.cat([chosen_mask, rejected_mask], dim=0)
+        concat_mask = torch.cat([chosen_mask, rejected_mask], dim=0)

-        # Build full attention mask: key-padding + causal
-        key_pad = concat_ids.bool()[:, None, None, :]  # [B*2, 1, 1, S]
-        S = key_pad.shape[-1]
-        causal = torch.tril(
-            torch.ones(S, S, dtype=torch.bool, device=concat_ids.device)
-        )[None, None, :, :]  # [1, 1, S, S]
-        full_mask = key_pad & causal  # [B*2, 1, S, S] — composed
-
-        log_pi = get_logprobs(
-            self.model,
-            concat_ids,
-            full_mask,
-            concat_loss_mask,
-            self.reduction,
-        )
+        log_pi = get_logprobs(self.model, concat_ids, concat_mask, self.reduction)

        with torch.no_grad():
            log_ref = get_logprobs(
-                self.ref_model,
-                concat_ids,
-                full_mask,
-                concat_loss_mask,
-                self.reduction,
+                self.ref_model, concat_ids, concat_mask, self.reduction
            )

        log_pi_chosen = log_pi[: chosen_ids.shape[0]]
@@ -337,73 +262,46 @@ class DPOStrategy(BaseStrategy):

        return dpo_loss

-    def supports_online(self) -> bool:
-        return True
-
-    def prepare_from_rollout(self, result: RolloutResult) -> Dict[str, Tensor]:
-        """Pick best/worst response per prompt by reward as chosen/rejected."""
-        rewards = result.rewards
-        responses = result.responses
-        masks = result.response_mask
-        best = rewards.argmax(dim=-1)
-        worst = rewards.argmin(dim=-1)
-        B = responses.shape[0]
-        idx = torch.arange(B, device=responses.device)
-        chosen = responses[idx, best]
-        chosen_mask = masks[idx, best].float()
-        rejected = responses[idx, worst]
-        rejected_mask = masks[idx, worst].float()
-        return {
-            "chosen": chosen,
-            "chosen_mask": chosen_mask,
-            "rejected": rejected,
-            "rejected_mask": rejected_mask,
-        }
-

@StrategyFactory.register("grpo")
 class GRPOStrategy(BaseStrategy):
    """Group Relative Policy Optimization strategy.

-    Implements GRPO following DeepSeek-R1 with token-level PPO clipping.
-    Advantages are group-normalized from scalar per-response rewards and
-    broadcast across all response tokens.  The loss is computed **only on
-    response tokens** — prompt tokens are masked out.
-
-    Three model roles are distinguished:
-
-    * **Policy** ``self.model`` — the model being trained.
-    * **Old policy** ``self.old_model`` — the behaviour policy that generated
-      the responses.  Used for the importance sampling ratio
-      ``ρ = π_θ / π_old``.  Synced externally after each data-generation round.
-    * **Reference model** ``self.ref_model`` — a frozen copy of the initial
-      policy (typically the SFT checkpoint) used **only** for the KL
-      regularisation term.  It is never updated during training.
+    On-policy GRPO following DeepSeek-R1: the policy model is updated while
+    a frozen ref_model stores the old-policy log-probs.  ratio = exp(logπ_θ - logπ_ref),
+    clipped PPO objective.  Call ``sync_ref_model()`` after each data-generation round.
    """

    def __init__(
        self,
        model: nn.Module,
        device: str,
-        old_model: nn.Module,
-        ref_model: nn.Module,
        clip_eps: float = 0.2,
        kl_coef: float = 0.01,
        group_size: int = 4,
+        reduction: str = "mean",
+        sync_interval: int = 200,
        **kwargs,
    ):
        super().__init__(model, device, **kwargs)
-        self.old_model = old_model
-        self.ref_model = ref_model
+        self.ref_model = create_ref_model(model)
        self.clip_eps = clip_eps
        self.kl_coef = kl_coef
        self.group_size = group_size
+        self.reduction = reduction
+        self.sync_interval = sync_interval
+        self._step = 0

-    def sync_old_model(self):
-        """Copy current policy weights to old model."""
-        self.old_model.load_state_dict(self.executor.unwrap_model(self.model))
+    def sync_ref_model(self):
+        """Copy current model weights to ref model."""
+        ref_state = self.model.state_dict()
+        self.ref_model.load_state_dict(ref_state)

    def compute_loss(self, batch: Dict[str, Tensor]) -> Tensor:
+        self._step += 1
+        if self._step % self.sync_interval == 0:
+            self.sync_ref_model()
+
        batch = move_to_device(batch, self.device)
        prompts = batch["prompts"]
        responses = batch["responses"]
@@ -414,101 +312,33 @@ class GRPOStrategy(BaseStrategy):
        responses_flat = responses.view(-1, response_len)
        masks_flat = masks.view(-1, response_len)
        prompt_expanded = prompts.unsqueeze(1).repeat(1, group_size, 1).flatten(0, 1)
-        prompt_mask = batch.get("prompt_mask")
-        if prompt_mask is None:
-            prompt_mask = prompts.ne(0)
-        prompt_mask_expanded = (
-            prompt_mask.unsqueeze(1).expand(-1, group_size, -1).flatten(0, 1)
-        )
-        prompt_len = prompt_expanded.size(1)

        full_sequences = torch.cat([prompt_expanded, responses_flat], dim=-1)
-        # Prompt tokens are masked out (0) so logprobs are computed only for
-        # response tokens.  get_logprobs shifts the mask by one position, so
-        # the first response token's logprob (predicted from the last prompt
-        # token) is correctly included.
-        full_masks = torch.cat(
-            [torch.zeros_like(prompt_expanded, dtype=torch.bool), masks_flat], dim=-1
+        full_masks = torch.cat([torch.ones_like(prompt_expanded), masks_flat], dim=-1)
+
+        log_probs_policy = get_logprobs(
+            self.model, full_sequences, full_masks, self.reduction
        )
+        log_probs_policy = log_probs_policy.view(batch_size, group_size)

-        # Build full attention mask: key-padding + causal
-        key_pad = torch.cat([prompt_mask_expanded, masks_flat.bool()], dim=-1)[
-            :, None, None, :
-        ]
-        S = key_pad.shape[-1]
-        causal = torch.tril(
-            torch.ones(S, S, dtype=torch.bool, device=full_sequences.device)
-        )[None, None, :, :]
-        attn_mask = key_pad & causal
-
-        # get_logprobs returns [B*G, S-1] (S = prompt_len + response_len).
-        # Response token logprobs occupy the last ``response_len`` positions
-        # (the first response token is predicted from the last prompt token).
-        token_log_probs_policy = get_logprobs(
-            self.model, full_sequences, attn_mask, full_masks, "none"
-        )[:, prompt_len - 1 :]
        with torch.no_grad():
-            token_log_probs_old = get_logprobs(
-                self.old_model, full_sequences, attn_mask, full_masks, "none"
-            )[:, prompt_len - 1 :]
-            token_log_probs_ref = get_logprobs(
-                self.ref_model, full_sequences, attn_mask, full_masks, "none"
-            )[:, prompt_len - 1 :]
+            log_probs_ref = get_logprobs(
+                self.ref_model, full_sequences, full_masks, self.reduction
+            )
+            log_probs_ref = log_probs_ref.view(batch_size, group_size)

-        # Reshape to [B, G, response_len]
-        token_log_probs_policy = token_log_probs_policy.view(batch_size, group_size, -1)
-        token_log_probs_old = token_log_probs_old.view(batch_size, group_size, -1)
-        token_log_probs_ref = token_log_probs_ref.view(batch_size, group_size, -1)
-        token_masks = masks_flat.view(batch_size, group_size, -1).float()
-
-        # Group-normalized advantages from scalar per-response rewards.
-        eps = 1e-8
+        eps = torch.finfo(log_probs_policy.dtype).eps
        mean = rewards.mean(dim=-1, keepdim=True)
-        std = rewards.std(dim=-1, keepdim=True, unbiased=False)
+        std = rewards.std(dim=-1, keepdim=True)
        advantages = (rewards - mean) / (std + eps)
-        # Broadcast scalar advantage to every response token: [B, G, 1]
-        advantages = advantages.unsqueeze(-1)

-        # Token-level ratio (π_θ / π_old) and PPO clipping.
-        log_ratio = token_log_probs_policy - token_log_probs_old
-        ratio = torch.exp(log_ratio)
+        ratio = torch.exp(log_probs_policy - log_probs_ref)

        surr1 = ratio * advantages
        surr2 = torch.clamp(ratio, 1 - self.clip_eps, 1 + self.clip_eps) * advantages
-        per_token_policy_loss = -torch.min(surr1, surr2)
-        token_count = token_masks.sum().clamp(min=1.0)
-        policy_loss = (per_token_policy_loss * token_masks).sum() / token_count
-
-        # KL penalty to frozen reference model with k1 estimator (non-negative):
-        # k1 = π_ref / π_θ - log(π_ref / π_θ) - 1, where π_ref / π_θ = exp(log_ref - log_policy).
-        log_ref_ratio = token_log_probs_ref - token_log_probs_policy
-        r = torch.exp(log_ref_ratio)
-        kl_per_token = r - torch.log(r + eps) - 1.0
-        kl_penalty = self.kl_coef * (kl_per_token * token_masks).sum() / token_count

+        policy_loss = -torch.min(surr1, surr2).mean()
+        kl_penalty = self.kl_coef * (log_probs_policy - log_probs_ref).square().mean()
        total_loss = policy_loss + kl_penalty

        return total_loss
-
-    def supports_online(self) -> bool:
-        return True
-
-    def prepare_from_rollout(self, result: RolloutResult) -> Dict[str, Tensor]:
-        return {
-            "prompts": result.prompts,
-            "prompt_mask": result.prompt_mask,
-            "responses": result.responses,
-            "masks": result.response_mask,
-            "rewards": result.rewards,
-        }
-
-    def _on_rollout_refresh(self):
-        """Sync the behaviour policy whenever a fresh rollout arrives."""
-        self.sync_old_model()
-
-
-# Factory aliases: online variants use the same strategy class; the
-# ``RolloutRunner`` is injected by ``TrainContextBuilder`` to enable
-# online mode, so no separate subclass is needed.
-StrategyFactory._entries["online_grpo"] = GRPOStrategy
-StrategyFactory._entries["online_dpo"] = DPOStrategy
@@ -9,6 +9,7 @@ from typing import IO, Callable, List, Optional, Protocol, runtime_checkable
 import torch
 import torch.distributed as dist
 import torch.nn as nn
+from torch.nn.utils import clip_grad_norm_
 from torch.utils.checkpoint import checkpoint as torch_checkpoint
 from tqdm import tqdm

@@ -17,7 +18,12 @@ from astrai.parallel import only_on_rank
 from astrai.parallel.setup import get_current_device
 from astrai.serialization import Checkpoint
 from astrai.trainer.metric_util import (
+    ctx_get_grad_max,
+    ctx_get_grad_mean,
+    ctx_get_grad_min,
+    ctx_get_grad_nan_num,
    ctx_get_grad_norm,
+    ctx_get_grad_std,
    ctx_get_loss,
    ctx_get_lr,
    ctx_get_val_loss,
@@ -80,9 +86,7 @@ class GradientClippingCallback(TrainCallback):
        self.max_grad_norm = max_grad_norm

    def on_optimizer_step(self, context: TrainContext):
-        context.grad_norm = context.executor.clip_grad_norm(
-            context.model, self.max_grad_norm
-        )
+        clip_grad_norm_(context.model.parameters(), self.max_grad_norm)


@CallbackFactory.register("gradient_checkpointing")
@@ -133,44 +137,51 @@ class CheckpointCallback(TrainCallback):
        save_dir: str,
        interval: int,
        weight_only: bool = False,
+        state_dict_fn: Optional[Callable[[nn.Module], dict]] = None,
        save_extra_fn: Optional[Callable[["TrainContext"], dict]] = None,
+        load_extra_fn: Optional[Callable[[dict, "TrainContext"], None]] = None,
    ):
        self.save_dir = save_dir
        self.interval = interval
        self.weight_only = weight_only
+        self.state_dict_fn = state_dict_fn
        self.save_extra_fn = save_extra_fn or CheckpointCallback.save_extra
-        self.last_ckpt_step = None
+        self.load_extra_fn = load_extra_fn or CheckpointCallback.load_extra
+        self.last_ckpt_iter = 0
+
+    @only_on_rank(0)
+    def _save_checkpoint(self, context: TrainContext):
+        save_path = os.path.join(
+            self.save_dir, f"epoch_{context.epoch}_iter_{context.iteration}"
+        )
+        state_dict = (
+            self.state_dict_fn(context.model)
+            if self.state_dict_fn
+            else context.model.state_dict()
+        )
+
+        extra = self.save_extra_fn(context)
+        context.checkpoint = Checkpoint(
+            state_dict=state_dict,
+            epoch=context.epoch,
+            iteration=context.iteration,
+            extra=extra,
+            meta=context.config.to_dict(),
+        )
+
+        context.checkpoint.save(save_path)
+        self.last_ckpt_iter = context.iteration

    def on_train_begin(self, context: TrainContext):
-        self.last_ckpt_step = context.optimizer_step
-
-    def _save_checkpoint(self, context: TrainContext):
-        self.last_ckpt_step = context.optimizer_step
-
-        with context.executor.checkpoint_context(context.model) as state_dict:
-            if state_dict is not None:
-                save_path = os.path.join(
-                    self.save_dir,
-                    f"epoch_{context.epoch}_step_{context.optimizer_step}",
-                )
-                extra = self.save_extra_fn(context)
-                meta = context.config.to_dict()
-                context.checkpoint = Checkpoint(
-                    state_dict=state_dict,
-                    epoch=context.epoch,
-                    consumed_samples=context.consumed_samples,
-                    config=context.model_config,
-                    extra=extra,
-                    meta=meta,
-                )
-                context.checkpoint.save(save_path)
+        if context.checkpoint and context.checkpoint.extra:
+            self.load_extra_fn(context.checkpoint.extra, context)

    def on_batch_end(self, context: TrainContext):
-        if context.optimizer_step - self.last_ckpt_step >= self.interval:
+        if context.iteration - self.last_ckpt_iter >= self.interval:
            self._save_checkpoint(context)

    def on_train_end(self, context: TrainContext):
-        if context.optimizer_step != self.last_ckpt_step:
+        if context.iteration != self.last_ckpt_iter:
            self._save_checkpoint(context)

    def on_error(self, context: TrainContext):
@@ -185,6 +196,12 @@ class CheckpointCallback(TrainCallback):
                extra[name] = obj.state_dict()
        return extra

+    @staticmethod
+    def load_extra(extra: dict, context: TrainContext):
+        for name in CheckpointCallback.extra_keys:
+            if name in extra:
+                getattr(context, name).load_state_dict(extra[name])
+

@CallbackFactory.register("progress_bar")
 class ProgressBarCallback(TrainCallback):
@@ -193,7 +210,7 @@ class ProgressBarCallback(TrainCallback):
    """

    def __init__(
-        self, num_epoch: int, log_interval: int = 100, file: Optional[IO[str]] = None
+        self, num_epoch: int, log_interval: int = 100, file: IO[str] = sys.stdout
    ):
        self.num_epoch = num_epoch
        self.log_interval = log_interval
@@ -202,24 +219,20 @@ class ProgressBarCallback(TrainCallback):

    @only_on_rank(0)
    def on_epoch_begin(self, context: TrainContext):
-        total_steps = len(context.dataloader) // context.executor.grad_accum_steps
        self.progress_bar = tqdm(
-            total=total_steps,
+            context.dataloader,
            desc=f"Epoch {context.epoch + 1}/{self.num_epoch}",
            dynamic_ncols=True,
-            file=self.file or sys.stdout,
+            file=self.file,
        )

    @only_on_rank(0)
-    def on_optimizer_step(self, context: TrainContext):
+    def on_batch_end(self, context: TrainContext):
        postfix = {
-            "step": f"{context.optimizer_step:d}",
            "loss": f"{context.loss:.4f}",
            "lr": f"{context.optimizer.param_groups[-1]['lr']:.2e}",
        }
-        if context.grad_norm is not None:
-            postfix["grad_norm"] = f"{context.grad_norm:.2f}"
-        if context.val_loss is not None:
+        if context.val_loss > 0:
            postfix["val_loss"] = f"{context.val_loss:.4f}"
        self.progress_bar.set_postfix(postfix)
        self.progress_bar.update(1)
@@ -231,20 +244,19 @@ class ProgressBarCallback(TrainCallback):
            self.progress_bar.close()


-@CallbackFactory.register("metric")
-class MetricCallback(TrainCallback):
+@CallbackFactory.register("metric_logger")
+class MetricLoggerCallback(TrainCallback):
    def __init__(
        self,
        log_dir: str,
        save_interval: int,
+        log_interval: int = 10,
        metrics: List[str] = None,
-        val_step: int = 0,
    ):
-        self.last_log_flush_step = None
+        self.last_log_iter = 0
        self.save_interval = save_interval
+        self.log_interval = log_interval
        self.metrics = metrics or ["loss", "lr"]
-        self.val_step = val_step
-        self._next_val_step = 0

        self.log_dir = Path(log_dir) if log_dir else Path.cwd() / "logs"
        self.log_dir.mkdir(parents=True, exist_ok=True)
@@ -256,28 +268,53 @@ class MetricCallback(TrainCallback):
            "lr": ctx_get_lr,
            "val_loss": ctx_get_val_loss,
            "grad_norm": ctx_get_grad_norm,
+            "grad_std": ctx_get_grad_std,
+            "grad_max": ctx_get_grad_max,
+            "grad_min": ctx_get_grad_min,
+            "grad_mean": ctx_get_grad_mean,
+            "grad_nan_num": ctx_get_grad_nan_num,
        }

-    def _metrics(self, context: TrainContext, names):
+    def _get_log_data(self, context: TrainContext):
        return {
-            m: self._metric_funcs[m](context)
-            for m in names
-            if self._metric_funcs[m](context) is not None
+            "timestamp": time.strftime("%Y-%m-%dT%H:%M:%S"),
+            "epoch": context.epoch,
+            "iter": context.iteration,
+            **{m: self._metric_funcs[m](context) for m in self.metrics},
        }

    @only_on_rank(0)
-    def _append(self, event_type: str, context: TrainContext, **extra):
-        entry = {
-            "type": event_type,
-            "timestamp": time.strftime("%Y-%m-%dT%H:%M:%S"),
-            "epoch": context.epoch,
-            "step": context.optimizer_step,
-            "consumed_samples": context.consumed_samples,
-            **extra,
-        }
-        self.log_cache.append(entry)
+    def _add_log(self, log_data):
+        self.log_cache.append(log_data)

-    def _run_validation(self, context: TrainContext) -> float:
+    @only_on_rank(0)
+    def _save_log(self, epoch, iter):
+        log_file = self.log_dir / f"epoch_{epoch}_iter_{iter}_metric.jsonl"
+
+        with open(log_file, "w") as f:
+            for log in self.log_cache:
+                f.write(json.dumps(log) + "\n")
+
+    def on_batch_end(self, context):
+        if context.iteration % self.log_interval == 0:
+            log_data = self._get_log_data(context)
+            self._add_log(log_data)
+
+        if context.iteration - self.last_log_iter >= self.save_interval:
+            self._save_log(context.epoch, context.iteration)
+            self.last_log_iter = context.iteration
+
+    def on_train_end(self, context):
+        if context.iteration != self.last_log_iter:
+            self._save_log(context.epoch, context.iteration)
+
+    def on_error(self, context):
+        self._save_log(context.epoch, context.iteration)
+
+
+@CallbackFactory.register("validation")
+class ValidationCallback(TrainCallback):
+    def _run_validation(self, context: TrainContext):
        context.model.eval()

        total_loss = 0.0
@@ -289,56 +326,27 @@ class MetricCallback(TrainCallback):
                total_loss += loss.item()
                num_batches += 1

+        avg_loss = total_loss / max(num_batches, 1)
+
        if context.world_size > 1 and dist.is_initialized():
-            stats = torch.tensor(
-                [total_loss, float(num_batches)], device=get_current_device()
-            )
-            dist.all_reduce(stats, op=dist.ReduceOp.SUM)
-            avg_loss = (stats[0] / stats[1]).item()
-        else:
-            avg_loss = total_loss / max(num_batches, 1)
+            loss_tensor = torch.tensor([avg_loss], device=get_current_device())
+            dist.all_reduce(loss_tensor, op=dist.ReduceOp.AVG)
+            avg_loss = loss_tensor.item()

+        context.val_loss = avg_loss
        context.model.train()
-        return avg_loss

-    def on_train_begin(self, context: TrainContext):
-        self.last_log_flush_step = context.optimizer_step
+        step_count = context.iteration // context.config.grad_accum_steps
+        logger.info(
+            f"Epoch {context.epoch + 1}, Step {step_count}, Val Loss: {avg_loss:.4f}"
+        )

-    @only_on_rank(0)
-    def _flush(self, epoch, step):
-        log_file = self.log_dir / f"epoch_{epoch}_step_{step}_metric.jsonl"
-        log_file.parent.mkdir(parents=True, exist_ok=True)
-        with open(log_file, "w") as f:
-            for log in self.log_cache:
-                f.write(json.dumps(log) + "\n")
-
-    def on_optimizer_step(self, context):
-        if (
-            context.val_dataloader is not None
-            and self.val_step > 0
-            and context.optimizer_step >= self._next_val_step
-        ):
-            context.val_loss = self._run_validation(context)
-            self._next_val_step = context.optimizer_step + self.val_step
-            self._append("validation", context, val_loss=context.val_loss)
-
-        step_metrics = [m for m in self.metrics if m != "val_loss"]
-        self._append("step", context, **self._metrics(context, step_metrics))
-
-        if context.optimizer_step - self.last_log_flush_step >= self.save_interval:
-            self._flush(context.epoch, context.optimizer_step)
-            self.last_log_flush_step = context.optimizer_step
-
-    def on_epoch_end(self, context):
-        self._append("epoch", context)
-
-    def on_train_end(self, context):
-        if (
-            self.last_log_flush_step is None
-            or context.optimizer_step != self.last_log_flush_step
-        ):
-            self._flush(context.epoch, context.optimizer_step)
-            self.last_log_flush_step = context.optimizer_step
-
-    def on_error(self, context):
-        self._flush(context.epoch, context.optimizer_step)
+    def on_optimizer_step(self, context: TrainContext):
+        if context.val_dataloader is None:
+            return
+        cfg = context.config
+        if cfg.val_step <= 0:
+            return
+        step_count = context.iteration // cfg.grad_accum_steps
+        if step_count % cfg.val_step == 0:
+            self._run_validation(context)
@@ -1,23 +1,16 @@
-import threading
 from dataclasses import dataclass, field
-from pathlib import Path
-from typing import Any, Dict, Optional, Self
+from typing import Optional, Self

-import torch
 import torch.nn as nn
-from torch.utils.data import DataLoader, random_split
+from torch.utils.data import DataLoader

 from astrai.config.train_config import TrainConfig
-from astrai.dataset import RDSampler
-from astrai.inference.core.scheduler import InferenceScheduler
-from astrai.model.components.lora import inject_lora
+from astrai.dataset import ResumableDistributedSampler
 from astrai.parallel.executor import BaseExecutor, ExecutorFactory
 from astrai.parallel.setup import get_current_device, get_rank, get_world_size
 from astrai.protocols import OptimizerProtocol, SchedulerProtocol
-from astrai.serialization import Checkpoint, load_json
-from astrai.tokenize import AutoTokenizer
-from astrai.trainer.rollout import RolloutGenerator, RolloutRunner
-from astrai.trainer.strategy import BaseStrategy, StrategyFactory, create_ref_model
+from astrai.serialization import Checkpoint
+from astrai.trainer.strategy import BaseStrategy, StrategyFactory


@dataclass
@@ -29,35 +22,17 @@ class TrainContext:
    scheduler: SchedulerProtocol = field(default=None)
    checkpoint: Checkpoint = field(default=None)
    config: TrainConfig = field(default=None)
-    model_config: dict = field(default_factory=dict)
    executor: BaseExecutor = field(default=None)
+
    epoch: int = field(default=0)
-    consumed_samples: int = field(default=0)
+    iteration: int = field(default=0)
    loss: float = field(default=0.0)
-    grad_norm: Optional[float] = field(default=None)
-    val_dataloader: Optional[DataLoader] = field(default=None)
-    val_loss: Optional[float] = field(default=None)
+    val_dataloader: DataLoader = field(default=None)
+    val_loss: float = field(default=0.0)

    world_size: int = field(default=1)
    rank: int = field(default=0)
-    kwargs: Dict[str, Any] = field(default_factory=dict)
-
-    _stop_event: threading.Event = field(default_factory=threading.Event)
-
-    @property
-    def stop_requested(self) -> bool:
-        return self._stop_event.is_set()
-
-    def request_stop(self) -> None:
-        self._stop_event.set()
-
-    @property
-    def optimizer_step(self) -> int:
-        return self.consumed_samples // (
-            self.config.batch_per_device
-            * self.world_size
-            * self.config.grad_accum_steps
-        )
+    kwargs: dict = field(default_factory=dict)


 class TrainContextBuilder:
@@ -66,12 +41,10 @@ class TrainContextBuilder:
        config: TrainConfig,
    ):
        self.config = config
-        self._param_path: Optional[str] = None
-        self._resume: bool = False
+        self._checkpoint: Optional[Checkpoint] = None

-    def with_param_path(self, param_path: Optional[str], resume: bool = False) -> Self:
-        self._param_path = param_path
-        self._resume = resume
+    def with_checkpoint(self, checkpoint: Optional[Checkpoint]) -> Self:
+        self._checkpoint = checkpoint
        return self

    def build(self) -> TrainContext:
@@ -84,196 +57,76 @@ class TrainContextBuilder:
            **cfg.executor_kwargs,
        )

-        model_config = {}
-        if self._param_path:
-            config_path = Path(self._param_path) / "config.json"
-            if config_path.exists():
-                model_config = load_json(config_path)
-
-        preloaded_state_dict = None
-        preloaded_epoch = cfg.start_epoch
-        preloaded_consumed = cfg.start_samples * get_world_size()
-        preloaded_checkpoint = None
-        if self._param_path:
-            checkpoint = Checkpoint.load_any(self._param_path)
-            if checkpoint is not None:
-                preloaded_state_dict = checkpoint.state_dict
-                if checkpoint.config:
-                    model_config = checkpoint.config
-                if self._resume:
-                    preloaded_epoch = checkpoint.epoch or cfg.start_epoch
-                    if checkpoint.consumed_samples > 0:
-                        per_step = (
-                            cfg.batch_per_device
-                            * get_world_size()
-                            * cfg.grad_accum_steps
-                        )
-                        preloaded_consumed = (
-                            checkpoint.consumed_samples // per_step
-                        ) * per_step
-                    else:
-                        preloaded_consumed = cfg.start_samples * get_world_size()
-                    preloaded_checkpoint = checkpoint
-
-        if not model_config and hasattr(cfg.model_fn(), "config"):
-            model_config = cfg.model_fn().config.to_dict()
-
-        def _before_wrap(m):
-            m = m.to(device=device)
-            if cfg.lora is not None:
-                inject_lora(
-                    m,
-                    r=cfg.lora.r,
-                    alpha=cfg.lora.alpha,
-                    target_modules=set(cfg.lora.target_modules),
-                )
-            if preloaded_state_dict is not None:
-                m.load_state_dict(preloaded_state_dict, strict=False)
-            return m
-
        context = TrainContext(
+            model=cfg.model,
            world_size=get_world_size(),
            rank=get_rank(),
            config=cfg,
-            model_config=model_config,
            executor=executor,
-            epoch=preloaded_epoch,
-            consumed_samples=preloaded_consumed,
-            checkpoint=preloaded_checkpoint,
        )

-        context.model, context.optimizer, context.scheduler = executor.prepare(
-            cfg.model_fn,
-            cfg.optimizer_fn,
-            cfg.scheduler_fn,
-            before_wrap=_before_wrap,
-        )
+        context.model = context.model.to(device=device)

-        train_dataset = cfg.dataset
-        val_dataset = cfg.val_dataset
-
-        if val_dataset is None and cfg.val_split is not None:
-            n_total = len(cfg.dataset)
-            n_val = max(1, int(n_total * cfg.val_split))
-            n_train = n_total - n_val
-            generator = torch.Generator().manual_seed(cfg.random_seed)
-            train_dataset, val_dataset = random_split(
-                cfg.dataset, [n_train, n_val], generator=generator
+        if self._checkpoint is not None:
+            context.epoch = max(self._checkpoint.epoch, cfg.start_epoch)
+            context.iteration = max(self._checkpoint.iteration, cfg.start_batch)
+            context.model.load_state_dict(self._checkpoint.state_dict)
+            context.checkpoint = self._checkpoint
+        else:
+            context.checkpoint = Checkpoint(
+                state_dict=context.model.state_dict(),
            )

-        sampler_offset = context.consumed_samples // context.world_size
-        sampler = RDSampler(
-            data_source=train_dataset,
+        context.optimizer = cfg.optimizer_fn(context.model)
+        context.scheduler = cfg.scheduler_fn(context.optimizer)
+
+        sampler_offset = context.iteration * cfg.batch_per_device
+        sampler = ResumableDistributedSampler(
+            data_source=cfg.dataset,
            start_epoch=context.epoch,
            start_iter=sampler_offset,
            seed=cfg.random_seed,
        )
        context.dataloader = DataLoader(
-            train_dataset,
+            cfg.dataset,
            batch_size=cfg.batch_per_device,
            sampler=sampler,
            num_workers=cfg.num_workers,
            pin_memory=cfg.pin_memory,
            prefetch_factor=cfg.prefetch_factor,
-            collate_fn=cfg.collate_fn,
        )

-        if val_dataset is not None:
-            val_sampler = RDSampler(
-                data_source=val_dataset,
+        if cfg.val_dataset is not None:
+            val_sampler = ResumableDistributedSampler(
+                data_source=cfg.val_dataset,
                start_epoch=0,
                start_iter=0,
                seed=cfg.random_seed,
                shuffle=False,
            )
            context.val_dataloader = DataLoader(
-                val_dataset,
+                cfg.val_dataset,
                batch_size=cfg.batch_per_device,
                sampler=val_sampler,
                num_workers=cfg.num_workers,
                pin_memory=cfg.pin_memory,
                prefetch_factor=cfg.prefetch_factor,
-                collate_fn=cfg.collate_fn,
            )

-        if context.checkpoint and context.checkpoint.extra:
-            extra = context.checkpoint.extra
-            for name in ("optimizer", "scheduler"):
-                if name in extra:
-                    obj = getattr(context, name, None)
-                    if obj is not None:
-                        obj.load_state_dict(extra[name])
-
-        strategy_kwargs = dict(cfg.extra_kwargs)
-
-        needs_ref = cfg.strategy in (
-            "dpo",
-            "grpo",
-            "online_grpo",
-            "online_dpo",
+        context.model, context.optimizer, context.dataloader, context.scheduler = (
+            executor.prepare(
+                context.model,
+                context.optimizer,
+                context.dataloader,
+                context.scheduler,
+            )
        )
-        needs_old = cfg.strategy in ("grpo", "online_grpo")
-
-        if needs_ref:
-            ref_model = create_ref_model(
-                cfg.model_fn, executor.unwrap_model(context.model)
-            ).to(device=device)
-            strategy_kwargs["ref_model"] = ref_model
-
-        old_model = None
-        if needs_old:
-            old_model = create_ref_model(
-                cfg.model_fn, executor.unwrap_model(context.model)
-            ).to(device=device)
-            strategy_kwargs["old_model"] = old_model

        context.strategy = StrategyFactory.create(
-            cfg.strategy,
            model=context.model,
+            train_type=cfg.strategy,
            device=device,
-            executor=executor,
-            **strategy_kwargs,
+            **cfg.extra_kwargs,
        )

-        # Enable online rollout when the train_type is an ``online_*`` variant.
-        is_online = cfg.strategy.startswith("online_")
-        if is_online:
-            if not context.strategy.supports_online():
-                raise ValueError(
-                    f"Strategy '{cfg.strategy}' does not support online rollout"
-                )
-            if cfg.reward_model_fn is None:
-                raise ValueError("reward_model_fn is required for online RL strategies")
-
-            tokenizer = AutoTokenizer.from_pretrained(self._param_path)
-            reward_model = cfg.reward_model_fn()
-
-            group_size = strategy_kwargs.get("group_size", 1)
-            rollout_batch_size = group_size * max(1, cfg.batch_per_device)
-            max_seq_len = getattr(context.model.config, "max_position_embeddings", None)
-
-            scheduler = InferenceScheduler(
-                model=context.model,
-                tokenizer=tokenizer,
-                max_batch_size=rollout_batch_size,
-                max_seq_len=max_seq_len,
-                max_prompt_len=max_seq_len or 4096,
-            )
-
-            generator = RolloutGenerator(
-                scheduler=scheduler,
-                tokenizer=tokenizer,
-                max_tokens=cfg.rollout_max_tokens,
-                group_size=group_size,
-                temperature=cfg.rollout_temperature,
-                top_k=cfg.rollout_top_k,
-                top_p=cfg.rollout_top_p,
-            )
-            runner = RolloutRunner(
-                generator=generator,
-                reward_model=reward_model,
-                rollout_interval=cfg.rollout_interval,
-            )
-            context.strategy.set_rollout_runner(runner)
-
        return context
@@ -1,14 +1,9 @@
 import logging
 from typing import List, Optional

-import torch.distributed as dist
-
 from astrai.config import TrainConfig
 from astrai.parallel.setup import spawn_parallel_fn
-from astrai.parallel.signal_handler import (
-    register_signal_handlers,
-    unregister_signal_handlers,
-)
+from astrai.serialization import Checkpoint
 from astrai.trainer.train_callback import (
    CallbackFactory,
    TrainCallback,
@@ -41,14 +36,15 @@ class Trainer:
                cfg.ckpt_interval,
            ),
            CallbackFactory.create(
-                "metric",
+                "metric_logger",
                log_dir=cfg.log_dir,
                save_interval=cfg.ckpt_interval,
+                log_interval=cfg.log_interval,
                metrics=cfg.metrics,
-                val_step=cfg.val_step,
            ),
            CallbackFactory.create("progress_bar", cfg.n_epoch),
            CallbackFactory.create("gradient_clipping", cfg.max_grad_norm),
+            CallbackFactory.create("validation"),
        ]
        return callbacks

@@ -58,13 +54,10 @@ class Trainer:
            if method:
                method(context)

-    def _trainer_loop(self, param_path: Optional[str] = None, resume: bool = False):
+    def _trainer_loop(self, checkpoint: Optional[Checkpoint] = None):
        context = (
-            TrainContextBuilder(self.train_config)
-            .with_param_path(param_path, resume=resume)
-            .build()
+            TrainContextBuilder(self.train_config).with_checkpoint(checkpoint).build()
        )
-        register_signal_handlers(context)
        executor = context.executor
        self._call_callbacks("on_train_begin", context)

@@ -72,53 +65,38 @@ class Trainer:
            context.model.train()

            for epoch in range(context.epoch, context.config.n_epoch):
-                if context.stop_requested:
-                    break
                context.epoch = epoch
                self._call_callbacks("on_epoch_begin", context)

                for batch in context.dataloader:
-                    if context.stop_requested:
-                        break
+                    self._call_callbacks("on_batch_begin", context)
+
                    with executor.accumulate(context.model):
-                        self._call_callbacks("on_batch_begin", context)
                        loss = context.strategy(batch)
                        context.loss = loss.item()
                        stand_loss = loss / executor.grad_accum_steps
                        executor.backward(stand_loss)
-                        context.consumed_samples += (
-                            context.config.batch_per_device * context.world_size
-                        )
+                        context.iteration += 1
                        self._call_callbacks("on_batch_end", context)

                        if executor.sync_gradients:
                            self._call_callbacks("on_optimizer_step", context)
                            context.optimizer.step()
-                            context.strategy.on_optimizer_step()
                            context.optimizer.zero_grad()

-                            if context.scheduler:
-                                context.scheduler.step()
+                        if context.scheduler:
+                            context.scheduler.step()

                self._call_callbacks("on_epoch_end", context)

-            if context.stop_requested:
-                logger.warning(
-                    "Training interrupted by signal, saving emergency checkpoint..."
-                )
-                self._call_callbacks("on_error", context)
-
        except Exception as e:
-            logger.error("Training failed: %s", str(e), exc_info=True)
+            logger.error(f"Training failed: {str(e)}", exc_info=True)
            self._call_callbacks("on_error", context)
            raise
        finally:
            self._call_callbacks("on_train_end", context)
-            if executor.use_distributed and dist.is_initialized():
-                dist.barrier()
-            unregister_signal_handlers()

-    def train(self, param_path: Optional[str] = None, resume: bool = False):
+    def train(self, checkpoint: Optional[Checkpoint] = None):
        cfg = self.train_config
        spawn_parallel_fn(
            self._trainer_loop,
@@ -128,6 +106,5 @@ class Trainer:
            master_port=cfg.master_port,
            device_type=cfg.device_type,
            start_method=cfg.start_method,
-            param_path=param_path,
-            resume=resume,
+            checkpoint=checkpoint,
        )
@@ -1,2 +0,0 @@
-# Source directory for CUDA kernels — build-time only.
-# Compiled .so files live in astrAI/_ext/.
@@ -1,48 +0,0 @@
-from pathlib import Path
-
-
-def _arch_flags() -> list[str]:
-    import torch
-
-    if torch.cuda.is_available():
-        cap = torch.cuda.get_device_capability()
-    else:
-        cap = (8, 0)
-    ver = f"{cap[0]}{cap[1]}"
-    flags = [f"-gencode=arch=compute_{ver},code=sm_{ver}"]
-    # tensor-core mma path (mma.sync.m16n8k16.bf16) requires sm_80+; decide the
-    # kernel dispatch at build time via this define rather than at runtime.
-    if cap[0] < 8:
-        flags.append("-DASTRAI_NO_MMA")
-    return flags
-
-
-_kernels_dir = Path("csrc/kernels")
-REGISTRY: dict[str, dict] = {}
-
-CXX_FLAGS = ["-O3", "-funroll-loops"]
-NVCC_FLAGS = [
-    "-O3",
-    "--expt-relaxed-constexpr",
-    "--use_fast_math",
-    "--ptxas-options=-O3,-v",
-    "--extra-device-vectorization",
-    "--threads=8",
-]
-
-
-def register(name: str, sources: list[str] | None = None, **kwargs):
-    if sources is None:
-        sources = [str(_kernels_dir / f"{name}.cu")]
-    REGISTRY[name] = {
-        "sources": sources,
-        "cxx_flags": [*CXX_FLAGS],
-        "nvcc_flags": [*NVCC_FLAGS, *_arch_flags()],
-        "extra_link_args": kwargs.pop("extra_link_args", []),
-        **kwargs,
-    }
-
-
-register("attn_decode")
-register("attn_prefill")
-register("attn_paged_decode")
@@ -1,68 +0,0 @@
-#pragma once
-
-
-template<typename T, typename AT = float>
-struct AttentionParams {
-    int batch;
-    int q_head;
-    int kv_head;
-    int q_len;
-    int kv_len;
-    int head_dim;
-    int use_mask;
-    int causal_offset;   // -1 = non-causal; >=0 = absolute position of first Q token
-    int num_splits;
-    float scale;
-
-    // Q strides (element offsets for each dim — layout-agnostic)
-    int q_stride_b, q_stride_h, q_stride_l, q_stride_d;
-    // KV strides (K and V share the same layout — only base pointers differ)
-    int kv_stride_b, kv_stride_h, kv_stride_l, kv_stride_d;
-
-    // Mask: 2D [batch, kv_len] (mask_q_stride=0) or 3D [batch, q_len, kv_len]
-    int mask_b_stride;   // = kv_len (both 2D and 3D)
-    int mask_q_stride;   // 2D: 0 (all q rows share); 3D: kv_len
-
-    const T* __restrict__ q;
-    const T* __restrict__ k;
-    const T* __restrict__ v;
-    const bool* __restrict__ mask;
-
-    T* __restrict__ o;
-    AT* __restrict__ o_part;
-    AT* __restrict__ ml_part;
-};
-
-template<typename T, typename AT = float>
-struct PagedAttentionParams {
-    int batch;
-    int q_head;
-    int kv_head;
-    int q_len;
-    int kv_len;
-    int head_dim;
-    int use_mask;
-    int causal_offset;
-    float scale;
-
-    int num_splits;
-    int page_size;
-    int max_pages;
-
-    // Q strides (layout-agnostic)
-    int q_stride_b, q_stride_h, q_stride_l, q_stride_d;
-
-    // Mask strides (2D or 3D)
-    int mask_b_stride;
-    int mask_q_stride;
-
-    const T* __restrict__ q;
-    const T* __restrict__ k_cache;
-    const T* __restrict__ v_cache;
-    const bool* __restrict__ mask;
-    const int64_t* __restrict__ page_table;
-
-    T* __restrict__ o;
-    AT* __restrict__ o_part;
-    AT* __restrict__ ml_part;
-};
@@ -1,37 +0,0 @@
-#include "attn_dispatchers.cuh"
-#include "attn_entry_utils.cuh"
-
-torch::Tensor attn_decode(
-    torch::Tensor q,
-    torch::Tensor k,
-    torch::Tensor v,
-    c10::optional<torch::Tensor> mask,
-    int64_t causal_offset,
-    double scale,
-    int64_t layout
-) {
-    AttentionParams<bf16> p;
-    attn_pack_params(q, k, v, mask, causal_offset, scale, layout, p);
-    TORCH_CHECK(p.q_len == 1, "Q seq_len must be 1");
-    TORCH_CHECK(p.head_dim % 32 == 0, "head_dim must be multiple of 32");
-
-    auto O = torch::empty_strided(q.sizes(), q.strides(), q.options());
-    auto O_view = (layout == 1) ? O.transpose(1, 2) : O;
-    p.o = (bf16*)O_view.data_ptr();
-
-    alloc_split_partials(p);
-    DISPATCH_HEAD_DIM(p.head_dim, dispatch_decode, p);
-    return O;
-}
-
-PYBIND11_MODULE(TORCH_EXTENSION_NAME, m) {
-    m.def("attn_decode", &attn_decode,
-        py::arg("q"),
-        py::arg("k"),
-        py::arg("v"),
-        py::arg("mask") = py::none(),
-        py::arg("causal_offset") = -1,
-        py::arg("scale") = 0.0,
-        py::arg("layout") = 0,
-        "GQA decode (tensor-core head-packing on sm_80+, scalar fallback)");
-}
@@ -1,129 +0,0 @@
-#pragma once
-#include <cuda_bf16.h>
-#include <float.h>
-#include "attn_common.h"
-#include "attn_warp_utils.cuh"
-constexpr int DC_CHUNK = 64;
-
-template <int HEAD_DIM, bool IsCausal, bool HasMask>
-__global__ void attn_decode_split_kv_kernel(AttentionParams<bf16> p) {
-    int batch = blockIdx.x / p.kv_head;
-    int kv_head = blockIdx.x % p.kv_head;
-    int split = blockIdx.z;
-    int group_size = blockDim.y;
-    int q_head = kv_head * group_size + threadIdx.y;
-    int lane = threadIdx.x;
-    int hd_per_thread = p.head_dim / 32;
-
-    // Q: [batch, q_head, q_len=1, head_dim] — stride-based
-    float q_reg[8];
-    int q_off = batch * p.q_stride_b + q_head * p.q_stride_h
-              + lane * hd_per_thread * p.q_stride_d;
-    for (int i = 0; i < hd_per_thread; i++)
-        q_reg[i] = __bfloat162float(p.q[q_off + i * p.q_stride_d]);
-
-    // KV: [batch, kv_head, kv_len, head_dim] — stride-based base
-    int kv_base = batch * p.kv_stride_b + kv_head * p.kv_stride_h;
-    int mask_base = batch * p.mask_b_stride;
-
-    float m = -FLT_MAX, d = 0.0f, acc_reg[8] = {0.0f};
-
-    extern __shared__ __align__(16) bf16 k_smem[];
-
-    // Split-KV: each split processes a contiguous subset of chunks
-    int chunks_total = (p.kv_len + DC_CHUNK - 1) / DC_CHUNK;
-    int chunks_per_split = (chunks_total + p.num_splits - 1) / p.num_splits;
-    int ch_begin = split * chunks_per_split;
-    int ch_end = min(chunks_total, ch_begin + chunks_per_split);
-
-    for (int ci = ch_begin; ci < ch_end; ci++) {
-        int chunk_start = ci * DC_CHUNK;
-        int this_chunk = min(DC_CHUNK, p.kv_len - chunk_start);
-
-        // Load K into shared memory (gather from strided global)
-        int total = this_chunk * p.head_dim;
-        for (int i = threadIdx.y * 32 + lane; i < total;
-             i += blockDim.x * blockDim.y) {
-            int s = i / p.head_dim;
-            int d_dim = i % p.head_dim;
-            int kv_idx = chunk_start + s;
-            int g_off = kv_base + kv_idx * p.kv_stride_l + d_dim * p.kv_stride_d;
-            k_smem[i] = p.k[g_off];
-        }
-        __syncthreads();
-
-        for (int s = 0; s < this_chunk; s++) {
-            float partial = 0.0f;
-            for (int i = 0; i < hd_per_thread; i++)
-                partial += q_reg[i] * __bfloat162float(
-                    k_smem[s * p.head_dim + lane * hd_per_thread + i]);
-            partial = warp_reduce_sum(partial) * p.scale;
-
-            int kv_idx = chunk_start + s;
-            if constexpr (HasMask) {
-                if (!p.mask[mask_base + kv_idx])
-                    partial = -FLT_MAX;
-            }
-            if constexpr (IsCausal) {
-                if (kv_idx > p.causal_offset)
-                    partial = -FLT_MAX;
-            }
-
-            float new_m = fmaxf(m, partial);
-            float alpha = expf(m - new_m);
-            float beta  = expf(partial - new_m);
-            d = d * alpha + beta;
-
-            int v_off = kv_base + kv_idx * p.kv_stride_l
-                        + lane * hd_per_thread * p.kv_stride_d;
-            for (int i = 0; i < hd_per_thread; i++)
-                acc_reg[i] = fmaf(acc_reg[i], alpha,
-                                  __bfloat162float(p.v[v_off + i * p.kv_stride_d]) * beta);
-            m = new_m;
-        }
-        __syncthreads();
-    }
-
-    // ---- write UN-normalised partials for this split ----
-    size_t bh = (size_t)batch * p.q_head + q_head;
-    size_t slot = bh * MAX_SPLITS + split;
-    int d0 = lane * hd_per_thread;
-    for (int i = 0; i < hd_per_thread; i++) {
-        int dd = d0 + i;
-        p.o_part[slot * p.head_dim + dd] = acc_reg[i];
-    }
-    if (lane == 0) {
-        p.ml_part[slot * 2] = m;
-        p.ml_part[slot * 2 + 1] = d;
-    }
-}
-
-__global__ void attn_decode_combine_kernel(AttentionParams<bf16> p) {
-    int bh = blockIdx.x;
-    int d = threadIdx.x;
-    if (d >= p.head_dim) return;
-
-    int batch = bh / p.q_head;
-    int q_head = bh % p.q_head;
-
-    size_t split_base = (size_t)bh * MAX_SPLITS;
-    const float* mlp = p.ml_part + split_base * 2;
-    const float* op = p.o_part + split_base * p.head_dim;
-
-    float m = -FLT_MAX, l = 0.0f, acc = 0.0f;
-    for (int s = 0; s < p.num_splits; s++) {
-        float mi = mlp[s * 2];
-        if (mi <= -FLT_MAX) continue;
-        float li = mlp[s * 2 + 1];
-        float nm = fmaxf(m, mi);
-        float corr = expf(m - nm);
-        float e = expf(mi - nm);
-        acc = fmaf(acc, corr, op[s * p.head_dim + d] * e);
-        l = fmaf(l, corr, li * e);
-        m = nm;
-    }
-
-    float inv = (l > 1e-20f) ? (1.0f / l) : 0.0f;
-    int o_off = batch * p.q_stride_b + q_head * p.q_stride_h + d * p.q_stride_d;
-    p.o[o_off] = __float2bfloat16(acc * inv);
-}
@@ -1,161 +0,0 @@
-#pragma once
-#include <cfloat>
-#include <cuda_bf16.h>
-#include "attn_common.h"
-#include "attn_mma_utils.cuh"
-#include "attn_warp_utils.cuh"
-
-// Split-K (FlashDecoding) tensor-core decode via GQA head-packing.
-// Decode has q_len == 1, so we pack G = q_head/kv_head query heads into the
-// M=16 rows of mma.sync.m16n8k16, turning G independent GEMVs into a single
-// GEMM that reuses each loaded K/V tile across all G heads.
-//
-// IsCausal and HasMask are compile-time bools — no runtime branch in the
-// inner compute loop.
-//
-// Traits = KernelTraits<HEAD_DIM, BC=32, WARPS=1, STAGES=<2 or 1>>.
-template <typename Traits, bool IsCausal, bool HasMask>
-__global__ void attn_decode_split_kv_mma_kernel(AttentionParams<bf16> p) {
-    const int lane = threadIdx.x;
-    const int gid = lane >> 2;
-    const int tid4 = lane & 3;
-
-    const int pass = blockIdx.x / p.kv_head;
-    const int kv_head = blockIdx.x % p.kv_head;
-    const int batch = blockIdx.y;
-    const int split = blockIdx.z;
-
-    constexpr int MAX_G = 16;
-    const int G_total = p.q_head / p.kv_head;
-    const int g_begin = pass * MAX_G;
-    const int G = min(MAX_G, G_total - g_begin);
-    const int q_head0 = kv_head * G_total + g_begin;
-
-    // Double-buffered shared memory for K/V (no sQ needed)
-    __shared__ __align__(16) bf16 sK[Traits::STAGES * Traits::BC * Traits::LD];
-    __shared__ __align__(16) bf16 sV[Traits::STAGES * Traits::BC * Traits::LD];
-
-    // Load Q directly from global into mma A-operand registers.
-    // stride_row = p.q_stride_h for decode (q_len=1).
-    const int q_base = batch * p.q_stride_b + q_head0 * p.q_stride_h;
-    const int qra = gid;
-    const int qrb = gid + 8;
-    const bool va = qra < G, vb = qrb < G;
-    unsigned Qa[Traits::KD][4];
-    load_q_mma_frags<Traits::KD>(p.q + q_base, p.q_stride_h, p.q_stride_d,
-                                  qra, qrb, va, vb, tid4, Qa);
-
-    float Oacc[Traits::DN8][4];
-    #pragma unroll
-    for (int j = 0; j < Traits::DN8; j++)
-        Oacc[j][0] = Oacc[j][1] = Oacc[j][2] = Oacc[j][3] = 0.0f;
-    float m0 = -FLT_MAX, m1 = -FLT_MAX, l0 = 0.0f, l1 = 0.0f;
-
-    const int kv_base = batch * p.kv_stride_b + kv_head * p.kv_stride_h;
-    const int tiles_total = (p.kv_len + Traits::BC - 1) / Traits::BC;
-    const int tiles_per_split = (tiles_total + p.num_splits - 1) / p.num_splits;
-    const int ti_begin = split * tiles_per_split;
-    const int ti_end = min(tiles_total, ti_begin + tiles_per_split);
-
-    // ---- Load tile lambda: predicated cp.async ----
-    auto load_tile = [&](int ti, int buf) {
-        int kv0 = ti * Traits::BC;
-        bf16* dK = sK + buf * Traits::BC * Traits::LD;
-        bf16* dV = sV + buf * Traits::BC * Traits::LD;
-        #pragma unroll
-        for (int i = lane * Traits::VEC; i < Traits::TOTAL;
-             i += Traits::NUM_THREADS * Traits::VEC) {
-            int r = i / Traits::HEAD_DIM, d = i % Traits::HEAD_DIM;
-            int kc = kv0 + r;
-            bool valid = kc < p.kv_len;
-            int off = r * Traits::LD + swiz_col(d, r, Traits::SWIZ_MASK);
-            int g_off = kv_base + kc * p.kv_stride_l + d * p.kv_stride_d;
-            cp_async_16_pred(&dK[off], &p.k[g_off], valid);
-            cp_async_16_pred(&dV[off], &p.v[g_off], valid);
-        }
-        cp_async_commit();
-    };
-
-    constexpr int BUF_MASK = (Traits::STAGES > 1) ? (Traits::STAGES - 1) : 0;
-
-    // Prologue
-    if (ti_begin < ti_end) {
-        load_tile(ti_begin, 0);
-    }
-
-    for (int ti = ti_begin; ti < ti_end; ti++) {
-        int buf = (ti - ti_begin) & BUF_MASK;
-
-        cp_async_wait_group<0>();
-        __syncwarp();
-        if constexpr (Traits::STAGES > 1) {
-            if (ti + 1 < ti_end)
-                load_tile(ti + 1, (ti + 1 - ti_begin) & BUF_MASK);
-        }
-
-        const bf16* bK = sK + buf * Traits::BC * Traits::LD;
-        const bf16* bV = sV + buf * Traits::BC * Traits::LD;
-        int kv0 = ti * Traits::BC;
-
-        float Sacc[Traits::NC8][4];
-        mma_compute_scores<Traits>(Qa, bK, lane, Sacc);
-
-        #pragma unroll
-        for (int n8 = 0; n8 < Traits::NC8; n8++)
-            Sacc[n8][0] *= p.scale, Sacc[n8][1] *= p.scale,
-            Sacc[n8][2] *= p.scale, Sacc[n8][3] *= p.scale;
-
-        // Decode: q_len=1, so qrow0=qrow1=0
-        int maxc = IsCausal ? min(p.kv_len, p.causal_offset + 1) : p.kv_len;
-        mma_softmax_tile<Traits, HasMask>(kv0, maxc, maxc,
-                                           0, 0,
-                                           p.mask_b_stride, 0,
-                                           batch,
-                                           p.mask,
-                                           Sacc, Oacc, m0, m1, l0, l1, lane);
-
-        mma_pv_accumulate<Traits>(Sacc, bV, lane, Oacc);
-        __syncwarp();
-
-        if constexpr (Traits::STAGES == 1) {
-            if (ti + 1 < ti_end)
-                load_tile(ti + 1, 0);
-        }
-    }
-
-    // ---- write UN-normalised partials for this split ----
-    auto split_slot = [&](int h) -> size_t {
-        size_t bh = (size_t)batch * p.q_head + h;
-        return bh * MAX_SPLITS + split;
-    };
-    #pragma unroll
-    for (int dn8 = 0; dn8 < Traits::DN8; dn8++) {
-        int d = dn8 * 8 + 2 * tid4;
-        int r0 = gid, r1 = gid + 8;
-        if (r0 < G) {
-            int h = q_head0 + r0;
-            float* op = p.o_part + split_slot(h) * Traits::HEAD_DIM;
-            op[d] = Oacc[dn8][0];
-            op[d + 1] = Oacc[dn8][1];
-        }
-        if (r1 < G) {
-            int h = q_head0 + r1;
-            float* op = p.o_part + split_slot(h) * Traits::HEAD_DIM;
-            op[d] = Oacc[dn8][2];
-            op[d + 1] = Oacc[dn8][3];
-        }
-    }
-    if (tid4 == 0) {
-        int r0 = gid, r1 = gid + 8;
-        if (r0 < G) {
-            int h = q_head0 + r0;
-            float* mp = p.ml_part + split_slot(h) * 2;
-            mp[0] = m0; mp[1] = l0;
-        }
-        if (r1 < G) {
-            int h = q_head0 + r1;
-            float* mp = p.ml_part + split_slot(h) * 2;
-            mp[0] = m1; mp[1] = l1;
-        }
-    }
-}
@@ -1,195 +0,0 @@
-#pragma once
-// Shared attention dispatchers — used by both production .cu and test .cu.
-// No torch dependency; pure CUDA.
-
-#include <cuda_runtime.h>
-#include <algorithm>
-#include "attn_warp_utils.cuh"
-#include "attn_prefill_split_q.cuh"
-#include "attn_decode_split_kv.cuh"
-#include "attn_paged_decode_split_kv.cuh"
-#ifndef ASTRAI_NO_MMA
-#include "attn_prefill_split_q_mma.cuh"
-#include "attn_decode_split_kv_mma.cuh"
-#include "attn_paged_decode_split_kv_mma.cuh"
-#endif
-
-// Split-KV: compute number of splits to fill all SMs for small-batch decode.
-inline int compute_num_splits(int base_blocks, int tiles_total) {
-    int sm_count = 0;
-    cudaDeviceGetAttribute(&sm_count, cudaDevAttrMultiProcessorCount, 0);
-    int n = (2 * sm_count + base_blocks - 1) / base_blocks;
-    return std::max(1, std::min(n, std::min(tiles_total, MAX_SPLITS)));
-}
-
-// ======================================================================
-// Prefill
-// ======================================================================
-
-#ifndef ASTRAI_NO_MMA
-template <int HEAD_DIM, bool IsCausal, bool HasMask>
-static inline void launch_prefill_mma(AttentionParams<bf16>& p) {
-    constexpr int WARPS = 4;
-    constexpr int BC = (HEAD_DIM <= 128) ? 32 : 16;
-    using Traits = KernelTraits<HEAD_DIM, BC, WARPS, 2>;
-    dim3 grid((p.q_len + Traits::BR * WARPS - 1) / (Traits::BR * WARPS), p.q_head, p.batch);
-    dim3 block(Traits::NUM_THREADS);
-    attn_prefill_split_q_mma_kernel<Traits, IsCausal, HasMask><<<grid, block>>>(p);
-}
-#endif
-
-template <int HEAD_DIM, bool IsCausal, bool HasMask>
-static inline void launch_prefill_scalar(AttentionParams<bf16>& p) {
-    constexpr int G = 8, ROWS = 32, P_BC = 32;
-    dim3 grid((p.q_len + ROWS - 1) / ROWS, p.q_head, p.batch);
-    dim3 block(G, ROWS);
-    attn_prefill_split_q_kernel_t<HEAD_DIM, G, ROWS, P_BC, IsCausal, HasMask><<<grid, block>>>(p);
-}
-
-template <int HEAD_DIM>
-static inline void dispatch_prefill(AttentionParams<bf16>& p) {
-    bool is_causal = (p.causal_offset >= 0);
-    bool has_mask = (p.use_mask && p.mask);
-
-#ifndef ASTRAI_NO_MMA
-    if (is_causal) {
-        if (has_mask)      launch_prefill_mma<HEAD_DIM, true, true>(p);
-        else               launch_prefill_mma<HEAD_DIM, true, false>(p);
-    } else {
-        if (has_mask)      launch_prefill_mma<HEAD_DIM, false, true>(p);
-        else               launch_prefill_mma<HEAD_DIM, false, false>(p);
-    }
-#else
-    if (is_causal) {
-        if (has_mask)      launch_prefill_scalar<HEAD_DIM, true, true>(p);
-        else               launch_prefill_scalar<HEAD_DIM, true, false>(p);
-    } else {
-        if (has_mask)      launch_prefill_scalar<HEAD_DIM, false, true>(p);
-        else               launch_prefill_scalar<HEAD_DIM, false, false>(p);
-    }
-#endif
-}
-
-// ======================================================================
-// Decode
-// ======================================================================
-
-#ifndef ASTRAI_NO_MMA
-template <int HEAD_DIM, bool IsCausal, bool HasMask>
-static inline void launch_decode_mma(AttentionParams<bf16>& p, int group_size) {
-    int G = p.q_head / p.kv_head;
-    constexpr int MAX_G = 16;
-    int num_passes = (G + MAX_G - 1) / MAX_G;
-    int tiles_total = (p.kv_len + 32 - 1) / 32;
-    p.num_splits = compute_num_splits(p.batch * p.kv_head, tiles_total);
-    constexpr int STAGES = (HEAD_DIM <= 128) ? 2 : 1;
-    using Traits = KernelTraits<HEAD_DIM, 32, 1, STAGES>;
-    dim3 grid(p.kv_head * num_passes, p.batch, p.num_splits);
-    attn_decode_split_kv_mma_kernel<Traits, IsCausal, HasMask><<<grid, 32>>>(p);
-}
-#endif
-
-template <int HEAD_DIM, bool IsCausal, bool HasMask>
-static inline void launch_decode_scalar(AttentionParams<bf16>& p, int group_size) {
-    int chunks_total = (p.kv_len + DC_CHUNK - 1) / DC_CHUNK;
-    p.num_splits = compute_num_splits(p.batch * p.kv_head, chunks_total);
-    size_t smem = DC_CHUNK * p.head_dim * sizeof(bf16);
-    int g = min(group_size, 32);  // cap at 32 to respect 1024-thread limit
-    dim3 grid(p.batch * p.kv_head, 1, p.num_splits);
-    dim3 block(32, g);
-    attn_decode_split_kv_kernel<HEAD_DIM, IsCausal, HasMask><<<grid, block, smem>>>(p);
-}
-
-template <int HEAD_DIM>
-static inline void dispatch_decode(AttentionParams<bf16>& p) {
-    bool is_causal = (p.causal_offset >= 0);
-    bool has_mask = (p.use_mask && p.mask);
-    int group_size = p.q_head / p.kv_head;
-
-#ifndef ASTRAI_NO_MMA
-    if (is_causal) {
-        if (has_mask)      launch_decode_mma<HEAD_DIM, true, true>(p, group_size);
-        else               launch_decode_mma<HEAD_DIM, true, false>(p, group_size);
-    } else {
-        if (has_mask)      launch_decode_mma<HEAD_DIM, false, true>(p, group_size);
-        else               launch_decode_mma<HEAD_DIM, false, false>(p, group_size);
-    }
-#else
-    if (is_causal) {
-        if (has_mask)      launch_decode_scalar<HEAD_DIM, true, true>(p, group_size);
-        else               launch_decode_scalar<HEAD_DIM, true, false>(p, group_size);
-    } else {
-        if (has_mask)      launch_decode_scalar<HEAD_DIM, false, true>(p, group_size);
-        else               launch_decode_scalar<HEAD_DIM, false, false>(p, group_size);
-    }
-#endif
-
-    attn_decode_combine_kernel<<<p.batch * p.q_head, p.head_dim>>>(p);
-}
-
-// ======================================================================
-// Paged Decode
-// ======================================================================
-
-#ifndef ASTRAI_NO_MMA
-template <int HEAD_DIM, bool IsCausal, bool HasMask>
-static inline void launch_paged_decode_mma(PagedAttentionParams<bf16>& p, int group_size) {
-    int G = p.q_head / p.kv_head;
-    constexpr int MAX_G = 16;
-    bool page_ok = (p.page_size >= 32);
-    if (G >= 1 && page_ok) {
-        int num_passes = (G + MAX_G - 1) / MAX_G;
-        int tiles_total = (p.kv_len + 32 - 1) / 32;
-        p.num_splits = compute_num_splits(p.batch * p.kv_head, tiles_total);
-        constexpr int STAGES = (HEAD_DIM <= 128) ? 2 : 1;
-        using Traits = KernelTraits<HEAD_DIM, 32, 1, STAGES>;
-        dim3 grid(p.kv_head * num_passes, p.batch, p.num_splits);
-        paged_attn_decode_split_kv_mma_kernel<Traits, IsCausal, HasMask> <<<grid, 32>>>(p);
-    } else {
-        int chunks_total = (p.kv_len + PDC_CHUNK - 1) / PDC_CHUNK;
-        p.num_splits = compute_num_splits(p.batch * p.kv_head, chunks_total);
-        size_t smem = PDC_CHUNK * p.head_dim * sizeof(bf16);
-        dim3 grid(p.batch * p.kv_head, 1, p.num_splits);
-        dim3 block(32, group_size);
-        paged_attn_decode_split_kv_kernel<HEAD_DIM, IsCausal, HasMask><<<grid, block, smem>>>(p);
-    }
-}
-#endif
-
-template <int HEAD_DIM, bool IsCausal, bool HasMask>
-static inline void launch_paged_decode_scalar(PagedAttentionParams<bf16>& p, int group_size) {
-    int chunks_total = (p.kv_len + PDC_CHUNK - 1) / PDC_CHUNK;
-    p.num_splits = compute_num_splits(p.batch * p.kv_head, chunks_total);
-    size_t smem = PDC_CHUNK * p.head_dim * sizeof(bf16);
-    int g = min(group_size, 32);  // cap at 32 to respect 1024-thread limit
-    dim3 grid(p.batch * p.kv_head, 1, p.num_splits);
-    dim3 block(32, g);
-    paged_attn_decode_split_kv_kernel<HEAD_DIM, IsCausal, HasMask><<<grid, block, smem>>>(p);
-}
-
-template <int HEAD_DIM>
-static inline void dispatch_paged_decode(PagedAttentionParams<bf16>& p) {
-    bool is_causal = (p.causal_offset >= 0);
-    bool has_mask = (p.use_mask && p.mask);
-    int group_size = p.q_head / p.kv_head;
-
-#ifndef ASTRAI_NO_MMA
-    if (is_causal) {
-        if (has_mask)      launch_paged_decode_mma<HEAD_DIM, true, true>(p, group_size);
-        else               launch_paged_decode_mma<HEAD_DIM, true, false>(p, group_size);
-    } else {
-        if (has_mask)      launch_paged_decode_mma<HEAD_DIM, false, true>(p, group_size);
-        else               launch_paged_decode_mma<HEAD_DIM, false, false>(p, group_size);
-    }
-#else
-    if (is_causal) {
-        if (has_mask)      launch_paged_decode_scalar<HEAD_DIM, true, true>(p, group_size);
-        else               launch_paged_decode_scalar<HEAD_DIM, true, false>(p, group_size);
-    } else {
-        if (has_mask)      launch_paged_decode_scalar<HEAD_DIM, false, true>(p, group_size);
-        else               launch_paged_decode_scalar<HEAD_DIM, false, false>(p, group_size);
-    }
-#endif
-
-    paged_attn_decode_combine_kernel<<<p.batch * p.q_head, p.head_dim>>>(p);
-}
@@ -1,171 +0,0 @@
-#pragma once
-#include <torch/extension.h>
-#include <c10/cuda/CUDAGuard.h>
-#include "attn_common.h"
-#include "attn_warp_utils.cuh"
-
-using bf16 = __nv_bfloat16;
-
-// Dispatch head_dim: shared macro — avoids C++20 lambda template syntax.
-// Usage: DISPATCH_HEAD_DIM(hd, fn, arg)
-//   Expands to: fn<32>(arg); fn<64>(arg); etc.
-#define DISPATCH_HEAD_DIM(hd, fn, arg) \
-    switch (hd) { \
-        case 32:  fn<32>(arg); break; \
-        case 64:  fn<64>(arg); break; \
-        case 128: fn<128>(arg); break; \
-        case 256: fn<256>(arg); break; \
-        default: \
-            TORCH_CHECK(false, "unsupported head_dim ", hd, \
-                         " (supported: 32, 64, 128, 256)"); \
-    }
-
-template<typename P>
-inline void alloc_split_partials(P& p) {
-    auto fopt = torch::TensorOptions().dtype(torch::kFloat32).device(torch::kCUDA);
-    auto o_part = torch::empty({p.batch, p.q_head, MAX_SPLITS, p.head_dim}, fopt);
-    auto ml_part = torch::empty({p.batch, p.q_head, MAX_SPLITS, 2}, fopt);
-    p.o_part = (float*)o_part.data_ptr();
-    p.ml_part = (float*)ml_part.data_ptr();
-}
-
-// ---- Shared Q-dims + strides extraction ----
-template <typename P>
-inline void extract_q_dims_and_strides(torch::Tensor& q, int64_t layout, P& p) {
-    if (layout == 1) q = q.transpose(1, 2);
-    p.batch = (int)q.size(0);
-    p.q_head = (int)q.size(1);
-    p.q_len = (int)q.size(2);
-    p.head_dim = (int)q.size(3);
-    p.q_stride_b = (int)q.stride(0);
-    p.q_stride_h = (int)q.stride(1);
-    p.q_stride_l = (int)q.stride(2);
-    p.q_stride_d = (int)q.stride(3);
-}
-
-// ---- Shared mask packing ----
-template <typename P>
-inline void pack_mask(const c10::optional<torch::Tensor>& mask, P& p) {
-    if (p.use_mask) {
-        auto m = mask.value();
-        TORCH_CHECK(m.is_cuda(), "mask must be on CUDA");
-        TORCH_CHECK(m.dtype() == torch::kBool, "mask must be bool");
-        TORCH_CHECK(m.size(0) == p.batch, "mask batch mismatch");
-        TORCH_CHECK(m.size(m.dim() - 1) == p.kv_len, "mask kv_len mismatch");
-        if (m.dim() == 2) {
-            p.mask_b_stride = (int)m.stride(0);
-            p.mask_q_stride = 0;
-        } else if (m.dim() == 3) {
-            TORCH_CHECK(m.size(1) == p.q_len, "mask q_len mismatch");
-            p.mask_b_stride = (int)m.stride(0);
-            p.mask_q_stride = (int)m.stride(1);
-        } else {
-            TORCH_CHECK(false, "mask must be 2D [batch, kv_len] or 3D [batch, q_len, kv_len]");
-        }
-        p.mask = m.data_ptr<bool>();
-    } else {
-        p.mask = nullptr;
-        p.mask_b_stride = 0;
-        p.mask_q_stride = 0;
-    }
-}
-
-// ---- attn_pack_params (contiguous KV) ----
-template<typename T>
-inline void attn_pack_params(
-    torch::Tensor q,
-    torch::Tensor k,
-    torch::Tensor v,
-    c10::optional<torch::Tensor> mask,
-    int64_t causal_offset,
-    double scale,
-    int64_t layout,
-    AttentionParams<T>& p
-) {
-    const at::cuda::OptionalCUDAGuard device_guard(device_of(q));
-
-    TORCH_CHECK(q.is_cuda() && k.is_cuda() && v.is_cuda());
-    TORCH_CHECK(q.dtype() == torch::kBFloat16);
-    TORCH_CHECK(k.dtype() == torch::kBFloat16);
-    TORCH_CHECK(v.dtype() == torch::kBFloat16);
-    TORCH_CHECK(k.sizes() == v.sizes(), "K and V must have identical shapes");
-    TORCH_CHECK(q.dim() == 4 && k.dim() == 4, "Q/K/V must be 4D");
-
-    extract_q_dims_and_strides(q, layout, p);
-
-    if (layout == 1) k = k.transpose(1, 2), v = v.transpose(1, 2);
-
-    p.kv_head = (int)k.size(1);
-    p.kv_len = (int)k.size(2);
-    TORCH_CHECK(k.size(3) == p.head_dim, "K/V head_dim must match Q");
-
-    p.kv_stride_b = (int)k.stride(0);
-    p.kv_stride_h = (int)k.stride(1);
-    p.kv_stride_l = (int)k.stride(2);
-    p.kv_stride_d = (int)k.stride(3);
-
-    p.causal_offset = (int)causal_offset;
-    p.use_mask = mask.has_value() ? 1 : 0;
-    p.scale = (scale > 0.0) ? (float)scale : 1.0f / sqrtf((float)p.head_dim);
-
-    p.q = (const T*)q.data_ptr();
-    p.k = (const T*)k.data_ptr();
-    p.v = (const T*)v.data_ptr();
-    p.o = nullptr;
-    p.o_part = nullptr;
-    p.ml_part = nullptr;
-
-    pack_mask(mask, p);
-}
-
-// ---- attn_pack_paged_params ----
-template<typename T>
-inline void attn_pack_paged_params(
-    torch::Tensor q,
-    torch::Tensor page_table,
-    torch::Tensor k_cache,
-    torch::Tensor v_cache,
-    int64_t page_size,
-    int64_t kv_len,
-    c10::optional<torch::Tensor> mask,
-    int64_t causal_offset,
-    double scale,
-    int64_t layout,
-    PagedAttentionParams<T>& p
-) {
-    const at::cuda::OptionalCUDAGuard device_guard(device_of(q));
-
-    TORCH_CHECK(q.is_cuda() && page_table.is_cuda() && k_cache.is_cuda() && v_cache.is_cuda());
-    TORCH_CHECK(q.dtype() == torch::kBFloat16, "q must be bf16");
-    TORCH_CHECK(k_cache.dtype() == torch::kBFloat16, "k_cache must be bf16");
-    TORCH_CHECK(v_cache.dtype() == torch::kBFloat16, "v_cache must be bf16");
-    TORCH_CHECK(page_table.dtype() == torch::kLong, "page_table must be int64");
-    TORCH_CHECK(k_cache.sizes() == v_cache.sizes(), "k_cache and v_cache must have identical shapes");
-
-    extract_q_dims_and_strides(q, layout, p);
-
-    p.kv_head = (int)k_cache.size(2);
-    p.kv_len = (int)kv_len;
-    p.page_size = (int)page_size;
-    p.max_pages = (int)page_table.size(1);
-
-    TORCH_CHECK(q.size(2) == 1, "Q seq_len must be 1 (decode)");
-    TORCH_CHECK(p.head_dim % 32 == 0, "head_dim must be multiple of 32");
-    TORCH_CHECK(k_cache.size(1) == page_size,
-                "k_cache dim 1 must equal page_size, got ",
-                k_cache.size(1), " vs ", page_size);
-
-    p.causal_offset = (int)causal_offset;
-    p.use_mask = (mask.has_value() && mask.value().defined()) ? 1 : 0;
-    p.scale = (scale > 0.0) ? (float)scale : 1.0f / sqrtf((float)p.head_dim);
-
-    p.page_table = page_table.data_ptr<int64_t>();
-    p.k_cache = (const T*)k_cache.data_ptr();
-    p.v_cache = (const T*)v_cache.data_ptr();
-    p.q = (const T*)q.data_ptr();
-    p.o = nullptr;
-    p.o_part = nullptr;
-    p.ml_part = nullptr;
-
-    pack_mask(mask, p);
-}
@@ -1,291 +0,0 @@
-#pragma once
-#include <cfloat>
-#include <cuda_fp16.h>
-#include <cuda_runtime.h>
-
-// ============================================================================
-// KernelTraits — FlashAttention-v2 style compile-time configuration bundle.
-//
-// Bundles all dimension-dependent constants so device functions only need a
-// single Traits template parameter rather than scattered <KD, NC8, KT2, ...>.
-// ============================================================================
-template <int HEAD_DIM_, int BC_, int WARPS_, int STAGES_>
-struct KernelTraits {
-    static constexpr int HEAD_DIM = HEAD_DIM_;
-    static constexpr int BC      = BC_;       // K/V tile size along seq dim
-    static constexpr int WARPS   = WARPS_;    // warps per block
-    static constexpr int STAGES  = STAGES_;   // double-buffer stages (1 or 2)
-
-    static constexpr int BR = 16;             // Q rows per warp (mma M=16)
-
-    // Derived: mma.sync.m16n8k16 tile counts
-    static constexpr int KD  = HEAD_DIM / 16;  // Q/K k-slides
-    static constexpr int NC8 = BC / 8;          // S n-tiles (N=8)
-    static constexpr int KT2 = BC / 16;         // P k-tiles (K=16)
-    static constexpr int DN8 = HEAD_DIM / 8;    // O n-tiles (N=8)
-
-    static constexpr int LD = HEAD_DIM;         // smem leading dim
-
-    // XOR swizzle chunk bits for ldmatrix bank-conflict avoidance.
-    // mask = log2(LD/8) bits, clamped to stay within LD.
-    static constexpr int SWIZ_MASK = (HEAD_DIM >= 64) ? 7 : (HEAD_DIM / 8 - 1);
-
-    static constexpr int NUM_THREADS = WARPS * 32;
-    static constexpr int VEC = 8;               // bf16 per cp.async unit (16 bytes)
-    static constexpr int TOTAL = BC * HEAD_DIM; // total elements per tile
-};
-
-// ---- PTX wrappers ----
-using bf16 = __nv_bfloat16;
-
-__device__ __forceinline__ void mma16816(float* d, const unsigned* a,
-                                          const unsigned* b, const float* c) {
-    asm volatile(
-        "mma.sync.aligned.m16n8k16.row.col.f32.bf16.bf16.f32 "
-        "{%0,%1,%2,%3}, {%4,%5,%6,%7}, {%8,%9}, {%10,%11,%12,%13};"
-        : "=f"(d[0]), "=f"(d[1]), "=f"(d[2]), "=f"(d[3])
-        : "r"(a[0]), "r"(a[1]), "r"(a[2]), "r"(a[3]), "r"(b[0]), "r"(b[1]),
-          "f"(c[0]), "f"(c[1]), "f"(c[2]), "f"(c[3]));
-}
-
-// read two adjacent bf16 from smem as one packed .b32 (elem0 low, elem1 high)
-__device__ __forceinline__ unsigned ld2(const bf16* p) {
-    return *reinterpret_cast<const unsigned*>(p);
-}
-
-// pack two floats into one bf16x2 as .b32
-__device__ __forceinline__ unsigned pk2(float a, float b) {
-    __nv_bfloat162 v = __floats2bfloat162_rn(a, b);
-    return *reinterpret_cast<unsigned*>(&v);
-}
-
-// pack two (non-contiguous) bf16 into one .b32
-__device__ __forceinline__ unsigned pkb(bf16 a, bf16 b) {
-    __nv_bfloat162 v;
-    v.x = a;
-    v.y = b;
-    return *reinterpret_cast<unsigned*>(&v);
-}
-
-// ldmatrix: cooperatively load mma fragments from smem (one instruction per
-// 16x16 / 16x8 tile) with the exact register layout mma expects.
-__device__ __forceinline__ void ldmatrix_x4(unsigned* r, const bf16* p) {
-    unsigned a = __cvta_generic_to_shared(p);
-    asm volatile("ldmatrix.sync.aligned.m8n8.x4.shared.b16 {%0,%1,%2,%3}, [%4];"
-                 : "=r"(r[0]), "=r"(r[1]), "=r"(r[2]), "=r"(r[3])
-                 : "r"(a));
-}
-__device__ __forceinline__ void ldmatrix_x2(unsigned* r, const bf16* p) {
-    unsigned a = __cvta_generic_to_shared(p);
-    asm volatile("ldmatrix.sync.aligned.m8n8.x2.shared.b16 {%0,%1}, [%2];"
-                 : "=r"(r[0]), "=r"(r[1])
-                 : "r"(a));
-}
-__device__ __forceinline__ void ldmatrix_x2_trans(unsigned* r, const bf16* p) {
-    unsigned a = __cvta_generic_to_shared(p);
-    asm volatile("ldmatrix.sync.aligned.m8n8.x2.trans.shared.b16 {%0,%1}, [%2];"
-                 : "=r"(r[0]), "=r"(r[1])
-                 : "r"(a));
-}
-
-// XOR swizzle for shared-memory column at 8-bf16 chunk granularity.
-__device__ __forceinline__ int swiz_col(int d, int r, int mask = 7) {
-    return ((d >> 3) ^ (r & mask)) << 3 | (d & 7);
-}
-
-// cp.async: copy 16 bytes (8 bf16) from global to shared memory directly.
-__device__ __forceinline__ void cp_async_16(bf16* smem_ptr, const void* gmem_ptr) {
-    unsigned smem_addr = __cvta_generic_to_shared(smem_ptr);
-    asm volatile("cp.async.ca.shared.global [%0], [%1], 16;"
-                 :: "r"(smem_addr), "l"(gmem_ptr));
-}
-
-// Predicated cp.async: copy 16 bytes when `pred`, otherwise zero-fill.
-// src_size=0 → no bytes read from src, so out-of-bounds src address is safe.
-__device__ __forceinline__ void cp_async_16_pred(bf16* smem_ptr,
-                                                  const void* gmem_ptr,
-                                                  bool pred) {
-    unsigned smem_addr = __cvta_generic_to_shared(smem_ptr);
-    int src_size = pred ? 16 : 0;
-    asm volatile("cp.async.ca.shared.global [%0], [%1], 16, %2;"
-                 :: "r"(smem_addr), "l"(gmem_ptr), "r"(src_size));
-}
-
-__device__ __forceinline__ void cp_async_commit() {
-    asm volatile("cp.async.commit_group;");
-}
-
-__device__ __forceinline__ void cp_async_wait_all() {
-    asm volatile("cp.async.wait_all;");
-}
-
-template <int N>
-__device__ __forceinline__ void cp_async_wait_group() {
-    asm volatile("cp.async.wait_group %0;" :: "n"(N));
-}
-
-// ---------------------------------------------------------------------------
-// Q-load: load query rows directly from global memory into mma A-operand
-// register layout. One call replaces ~15 duplicated lines in each MMA kernel.
-// stride_row is p.q_stride_h for decode (q_len=1, G heads) or
-//              p.q_stride_l for prefill (multi-q rows).
-// ---------------------------------------------------------------------------
-template <int KD>
-__device__ inline void load_q_mma_frags(
-    const bf16* __restrict__ q,
-    int stride_row,
-    int stride_d,
-    int qra, int qrb,
-    bool va, bool vb,
-    int tid4,
-    unsigned Qa[KD][4])
-{
-    #pragma unroll
-    for (int kt = 0; kt < KD; kt++) {
-        int c = kt * 16 + tid4 * 2;
-        const unsigned* pau = reinterpret_cast<const unsigned*>(
-            &q[qra * stride_row + c * stride_d]);
-        const unsigned* pbu = reinterpret_cast<const unsigned*>(
-            &q[qrb * stride_row + c * stride_d]);
-        Qa[kt][0] = va ? pau[0] : 0u;
-        Qa[kt][1] = vb ? pbu[0] : 0u;
-        Qa[kt][2] = va ? pau[4] : 0u;
-        Qa[kt][3] = vb ? pbu[4] : 0u;
-    }
-}
-
-// ---------------------------------------------------------------------------
-// S = Q @ K^T  (Qa pre-loaded by the caller; scale applied post-mma in the
-// caller to avoid bf16 precision loss).
-// Traits provides KD, NC8, LD, and SWIZ_MASK.
-// ---------------------------------------------------------------------------
-template <typename Traits>
-__device__ inline void mma_compute_scores(
-    const unsigned Qa[Traits::KD][4],
-    const bf16* __restrict__ sK,
-    int lane,
-    float Sacc[Traits::NC8][4])
-{
-    #pragma unroll
-    for (int n8 = 0; n8 < Traits::NC8; n8++) {
-        Sacc[n8][0] = Sacc[n8][1] = Sacc[n8][2] = Sacc[n8][3] = 0.0f;
-        int krow_l = n8 * 8 + (lane & 7);
-        int kcol_h = (lane & 8) ? 8 : 0;
-        #pragma unroll
-        for (int kt = 0; kt < Traits::KD; kt++) {
-            unsigned b[2];
-            ldmatrix_x2(b, &sK[krow_l * Traits::LD
-                + swiz_col(kt * 16 + kcol_h, krow_l, Traits::SWIZ_MASK)]);
-            mma16816(Sacc[n8], Qa[kt], b, Sacc[n8]);
-        }
-    }
-}
-
-// ---------------------------------------------------------------------------
-// Online softmax + Oacc rescale for one K/V tile.
-//
-// HasMask is a compile-time template bool: when false, the mask branch is
-// entirely dead-code-eliminated from the inner unrolled loop.
-// ---------------------------------------------------------------------------
-template <typename Traits, bool HasMask>
-__device__ inline void mma_softmax_tile(
-    int kv0,
-    int maxc0, int maxc1,
-    int qrow0, int qrow1,
-    int mask_b_stride, int mask_q_stride,
-    int mask_batch,
-    const bool* __restrict__ mask,
-    float Sacc[Traits::NC8][4],
-    float Oacc[Traits::DN8][4],
-    float& m0, float& m1,
-    float& l0, float& l1,
-    int lane)
-{
-    int tid4 = lane & 3;
-
-    float rmax0 = -FLT_MAX, rmax1 = -FLT_MAX;
-    int mask_base0 = mask_batch * mask_b_stride + qrow0 * mask_q_stride;
-    int mask_base1 = mask_batch * mask_b_stride + qrow1 * mask_q_stride;
-    #pragma unroll
-    for (int n8 = 0; n8 < Traits::NC8; n8++) {
-        int cc = kv0 + n8 * 8 + 2 * tid4;
-        int c1 = cc + 1;
-        bool b0 = (cc >= maxc0) || (HasMask && !mask[mask_base0 + cc]);
-        bool b1 = (c1 >= maxc0) || (HasMask && !mask[mask_base0 + c1]);
-        bool b2 = (cc >= maxc1) || (HasMask && !mask[mask_base1 + cc]);
-        bool b3 = (c1 >= maxc1) || (HasMask && !mask[mask_base1 + c1]);
-        float s0 = b0 ? -FLT_MAX : Sacc[n8][0];
-        float s1 = b1 ? -FLT_MAX : Sacc[n8][1];
-        float s2 = b2 ? -FLT_MAX : Sacc[n8][2];
-        float s3 = b3 ? -FLT_MAX : Sacc[n8][3];
-        Sacc[n8][0] = s0; Sacc[n8][1] = s1;
-        Sacc[n8][2] = s2; Sacc[n8][3] = s3;
-        rmax0 = fmaxf(rmax0, fmaxf(s0, s1));
-        rmax1 = fmaxf(rmax1, fmaxf(s2, s3));
-    }
-    rmax0 = fmaxf(rmax0, __shfl_xor_sync(0xFFFFFFFF, rmax0, 1));
-    rmax0 = fmaxf(rmax0, __shfl_xor_sync(0xFFFFFFFF, rmax0, 2));
-    rmax1 = fmaxf(rmax1, __shfl_xor_sync(0xFFFFFFFF, rmax1, 1));
-    rmax1 = fmaxf(rmax1, __shfl_xor_sync(0xFFFFFFFF, rmax1, 2));
-
-    float nm0 = fmaxf(m0, rmax0), nm1 = fmaxf(m1, rmax1);
-    float corr0 = __expf(m0 - nm0);
-    float corr1 = __expf(m1 - nm1);
-    float pn0 = (nm0 == -FLT_MAX) ? 0.0f : 1.0f;
-    float pn1 = (nm1 == -FLT_MAX) ? 0.0f : 1.0f;
-
-    float rsum0 = 0.0f, rsum1 = 0.0f;
-    #pragma unroll
-    for (int n8 = 0; n8 < Traits::NC8; n8++) {
-        float p0 = pn0 * __expf(Sacc[n8][0] - nm0);
-        float p1 = pn0 * __expf(Sacc[n8][1] - nm0);
-        float p2 = pn1 * __expf(Sacc[n8][2] - nm1);
-        float p3 = pn1 * __expf(Sacc[n8][3] - nm1);
-        Sacc[n8][0] = p0; Sacc[n8][1] = p1;
-        Sacc[n8][2] = p2; Sacc[n8][3] = p3;
-        rsum0 += p0 + p1;
-        rsum1 += p2 + p3;
-    }
-    rsum0 += __shfl_xor_sync(0xFFFFFFFF, rsum0, 1);
-    rsum0 += __shfl_xor_sync(0xFFFFFFFF, rsum0, 2);
-    rsum1 += __shfl_xor_sync(0xFFFFFFFF, rsum1, 1);
-    rsum1 += __shfl_xor_sync(0xFFFFFFFF, rsum1, 2);
-    l0 = l0 * corr0 + rsum0;
-    l1 = l1 * corr1 + rsum1;
-    m0 = nm0; m1 = nm1;
-
-    #pragma unroll
-    for (int j = 0; j < Traits::DN8; j++) {
-        Oacc[j][0] *= corr0; Oacc[j][1] *= corr0;
-        Oacc[j][2] *= corr1; Oacc[j][3] *= corr1;
-    }
-}
-
-// ---------------------------------------------------------------------------
-// O += P @ V  (Sacc must contain P = attention weights after softmax).
-// Traits provides DN8, KT2, LD, and SWIZ_MASK.
-// ---------------------------------------------------------------------------
-template <typename Traits>
-__device__ inline void mma_pv_accumulate(
-    float Sacc[][4],
-    const bf16* __restrict__ sV,
-    int lane,
-    float Oacc[Traits::DN8][4])
-{
-    #pragma unroll
-    for (int kt2 = 0; kt2 < Traits::KT2; kt2++) {
-        unsigned Pa[4];
-        Pa[0] = pk2(Sacc[kt2 * 2][0], Sacc[kt2 * 2][1]);
-        Pa[1] = pk2(Sacc[kt2 * 2][2], Sacc[kt2 * 2][3]);
-        Pa[2] = pk2(Sacc[kt2 * 2 + 1][0], Sacc[kt2 * 2 + 1][1]);
-        Pa[3] = pk2(Sacc[kt2 * 2 + 1][2], Sacc[kt2 * 2 + 1][3]);
-        int vrow_l = kt2 * 16 + (lane & 15);
-        #pragma unroll
-        for (int dn8 = 0; dn8 < Traits::DN8; dn8++) {
-            unsigned b[2];
-            ldmatrix_x2_trans(b, &sV[vrow_l * Traits::LD
-                + swiz_col(dn8 * 8, vrow_l, Traits::SWIZ_MASK)]);
-            mma16816(Oacc[dn8], Pa, b, Oacc[dn8]);
-        }
-    }
-}
@@ -1,42 +0,0 @@
-#include "attn_dispatchers.cuh"
-#include "attn_entry_utils.cuh"
-
-torch::Tensor attn_paged_decode(
-    torch::Tensor q,
-    torch::Tensor page_table,
-    torch::Tensor k_cache,
-    torch::Tensor v_cache,
-    int64_t page_size,
-    int64_t kv_len,
-    c10::optional<torch::Tensor> mask,
-    int64_t causal_offset,
-    double scale,
-    int64_t layout
-) {
-    PagedAttentionParams<bf16> p;
-    attn_pack_paged_params(q, page_table, k_cache, v_cache,
-                           page_size, kv_len, mask, causal_offset, scale, layout, p);
-
-    auto O = torch::empty_strided(q.sizes(), q.strides(), q.options());
-    auto O_view = (layout == 1) ? O.transpose(1, 2) : O;
-    p.o = (bf16*)O_view.data_ptr();
-
-    alloc_split_partials(p);
-    DISPATCH_HEAD_DIM(p.head_dim, dispatch_paged_decode, p);
-    return O;
-}
-
-PYBIND11_MODULE(TORCH_EXTENSION_NAME, m) {
-    m.def("attn_paged_decode", &attn_paged_decode,
-        py::arg("q"),
-        py::arg("page_table"),
-        py::arg("k_cache"),
-        py::arg("v_cache"),
-        py::arg("page_size"),
-        py::arg("kv_len"),
-        py::arg("mask") = py::none(),
-        py::arg("causal_offset") = -1,
-        py::arg("scale") = 0.0,
-        py::arg("layout") = 0,
-        "Paged GQA decode — split-KV with direct page-table access.");
-}
@@ -1,146 +0,0 @@
-#pragma once
-#include <cuda_bf16.h>
-#include <float.h>
-#include "attn_common.h"
-#include "attn_warp_utils.cuh"
-constexpr int PDC_CHUNK = 64;
-
-template <int HEAD_DIM, bool IsCausal, bool HasMask>
-__global__ void paged_attn_decode_split_kv_kernel(PagedAttentionParams<bf16> p) {
-    int batch = blockIdx.x / p.kv_head;
-    int kv_head = blockIdx.x % p.kv_head;
-    int split = blockIdx.z;
-    int group_size = blockDim.y;
-    int q_head = kv_head * group_size + threadIdx.y;
-    int lane = threadIdx.x;
-    int hd_per_thread = p.head_dim / 32;
-
-    float q_reg[8];
-    int q_off = batch * p.q_stride_b + q_head * p.q_stride_h
-              + lane * hd_per_thread * p.q_stride_d;
-    #pragma unroll
-    for (int i = 0; i < hd_per_thread; i++)
-        q_reg[i] = __bfloat162float(p.q[q_off + i * p.q_stride_d]);
-
-    float m = -FLT_MAX, d = 0.0f, acc_reg[8] = {0.0f};
-
-    extern __shared__ __align__(16) bf16 k_smem[];
-
-    int chunks_total = (p.kv_len + PDC_CHUNK - 1) / PDC_CHUNK;
-    int chunks_per_split = (chunks_total + p.num_splits - 1) / p.num_splits;
-    int ch_begin = split * chunks_per_split;
-    int ch_end = min(chunks_total, ch_begin + chunks_per_split);
-
-    const int mask_base = batch * p.mask_b_stride;
-
-    for (int ci = ch_begin; ci < ch_end; ci++) {
-        int chunk_start = ci * PDC_CHUNK;
-        int this_chunk = min(PDC_CHUNK, p.kv_len - chunk_start);
-
-        int total = this_chunk * p.head_dim;
-        for (int i = threadIdx.y * 32 + lane; i < total;
-             i += blockDim.x * blockDim.y) {
-            int s = i / p.head_dim;
-            int d_dim = i % p.head_dim;
-            int pos = chunk_start + s;
-            int logical_page = pos / p.page_size;
-            int page_offset = pos % p.page_size;
-            int phys_page = p.page_table[batch * p.max_pages + logical_page];
-            if (phys_page >= 0) {
-                int64_t off = (int64_t)phys_page * p.page_size * p.kv_head * p.head_dim
-                            + (int64_t)page_offset * p.kv_head * p.head_dim
-                            + (int64_t)kv_head * p.head_dim
-                            + d_dim;
-                k_smem[i] = p.k_cache[off];
-            } else {
-                k_smem[i] = __float2bfloat16(0.0f);
-            }
-        }
-        __syncthreads();
-
-        for (int s = 0; s < this_chunk; s++) {
-            float partial = 0.0f;
-            #pragma unroll
-            for (int i = 0; i < hd_per_thread; i++)
-                partial += q_reg[i] * __bfloat162float(
-                    k_smem[s * p.head_dim + lane * hd_per_thread + i]);
-            partial = warp_reduce_sum(partial) * p.scale;
-
-            int kv_idx = chunk_start + s;
-            if constexpr (HasMask) {
-                if (!p.mask[mask_base + kv_idx])
-                    partial = -FLT_MAX;
-            }
-            if constexpr (IsCausal) {
-                if (kv_idx > p.causal_offset)
-                    partial = -FLT_MAX;
-            }
-
-            float new_m = fmaxf(m, partial);
-            float alpha = expf(m - new_m);
-            float beta  = expf(partial - new_m);
-            d = d * alpha + beta;
-
-            int pos = chunk_start + s;
-            int logical_page = pos / p.page_size;
-            int page_offset = pos % p.page_size;
-            int phys_page = p.page_table[batch * p.max_pages + logical_page];
-            if (phys_page >= 0) {
-                int64_t v_base = (int64_t)phys_page * p.page_size * p.kv_head * p.head_dim
-                               + (int64_t)page_offset * p.kv_head * p.head_dim
-                               + (int64_t)kv_head * p.head_dim;
-                #pragma unroll
-                for (int i = 0; i < hd_per_thread; i++)
-                    acc_reg[i] = fmaf(acc_reg[i], alpha,
-                                      __bfloat162float(p.v_cache[v_base + lane * hd_per_thread + i]) * beta);
-            } else {
-                #pragma unroll
-                for (int i = 0; i < hd_per_thread; i++)
-                    acc_reg[i] = fmaf(acc_reg[i], alpha, 0.0f);
-            }
-            m = new_m;
-        }
-        __syncthreads();
-    }
-
-    size_t bh = (size_t)batch * p.q_head + q_head;
-    size_t slot = bh * MAX_SPLITS + split;
-    int d0 = lane * hd_per_thread;
-    #pragma unroll
-    for (int i = 0; i < hd_per_thread; i++)
-        p.o_part[slot * p.head_dim + (d0 + i)] = acc_reg[i];
-    if (lane == 0) {
-        p.ml_part[slot * 2] = m;
-        p.ml_part[slot * 2 + 1] = d;
-    }
-}
-
-__global__ void paged_attn_decode_combine_kernel(PagedAttentionParams<bf16> p) {
-    int bh = blockIdx.x;
-    int d = threadIdx.x;
-    if (d >= p.head_dim) return;
-
-    int batch = bh / p.q_head;
-    int q_head = bh % p.q_head;
-
-    size_t split_base = (size_t)bh * MAX_SPLITS;
-    const float* mlp = p.ml_part + split_base * 2;
-    const float* op = p.o_part + split_base * p.head_dim;
-
-    float m = -FLT_MAX, l = 0.0f, acc = 0.0f;
-    for (int s = 0; s < p.num_splits; s++) {
-        float mi = mlp[s * 2];
-        if (mi <= -FLT_MAX) continue;
-        float li = mlp[s * 2 + 1];
-        float nm = fmaxf(m, mi);
-        float corr = expf(m - nm);
-        float e = expf(mi - nm);
-        acc = fmaf(acc, corr, op[s * p.head_dim + d] * e);
-        l = fmaf(l, corr, li * e);
-        m = nm;
-    }
-
-    float inv = (l > 1e-20f) ? (1.0f / l) : 0.0f;
-    int o_off = batch * p.q_stride_b + q_head * p.q_stride_h + d * p.q_stride_d;
-    p.o[o_off] = __float2bfloat16(acc * inv);
-}
@@ -1,161 +0,0 @@
-#pragma once
-#include <cfloat>
-#include <cuda_bf16.h>
-#include "attn_common.h"
-#include "attn_mma_utils.cuh"
-#include "attn_warp_utils.cuh"
-
-// Paged split-KV tensor-core decode via GQA head-packing.
-// Reads K/V directly from the page pool through a page table — one tile
-// (BC=32) fits within a single page (page_size >= 32), so the page-table
-// lookup happens once per tile for cp.async.
-//
-// IsCausal and HasMask are compile-time bools.
-template <typename Traits, bool IsCausal, bool HasMask>
-__global__ void paged_attn_decode_split_kv_mma_kernel(PagedAttentionParams<bf16> p) {
-    const int lane = threadIdx.x;
-    const int gid = lane >> 2;
-    const int tid4 = lane & 3;
-
-    const int pass = blockIdx.x / p.kv_head;
-    const int kv_head = blockIdx.x % p.kv_head;
-    const int batch = blockIdx.y;
-    const int split = blockIdx.z;
-
-    constexpr int MAX_G = 16;
-    const int G_total = p.q_head / p.kv_head;
-    const int g_begin = pass * MAX_G;
-    const int G = min(MAX_G, G_total - g_begin);
-    const int q_head0 = kv_head * G_total + g_begin;
-
-    __shared__ __align__(16) bf16 sK[Traits::STAGES * Traits::BC * Traits::LD];
-    __shared__ __align__(16) bf16 sV[Traits::STAGES * Traits::BC * Traits::LD];
-
-    const int q_base = batch * p.q_stride_b + q_head0 * p.q_stride_h;
-    const int qra = gid;
-    const int qrb = gid + 8;
-    const bool va = qra < G, vb = qrb < G;
-    unsigned Qa[Traits::KD][4];
-    load_q_mma_frags<Traits::KD>(p.q + q_base, p.q_stride_h, p.q_stride_d,
-                                  qra, qrb, va, vb, tid4, Qa);
-
-    float Oacc[Traits::DN8][4];
-    #pragma unroll
-    for (int j = 0; j < Traits::DN8; j++)
-        Oacc[j][0] = Oacc[j][1] = Oacc[j][2] = Oacc[j][3] = 0.0f;
-    float m0 = -FLT_MAX, m1 = -FLT_MAX, l0 = 0.0f, l1 = 0.0f;
-
-    const int tiles_total = (p.kv_len + Traits::BC - 1) / Traits::BC;
-    const int tiles_per_split = (tiles_total + p.num_splits - 1) / p.num_splits;
-    const int ti_begin = split * tiles_per_split;
-    const int ti_end = min(tiles_total, ti_begin + tiles_per_split);
-
-    const int64_t page_stride = (int64_t)p.page_size * p.kv_head * Traits::HEAD_DIM;
-    const int64_t pos_stride  = (int64_t)p.kv_head * Traits::HEAD_DIM;
-    const int64_t head_off    = (int64_t)kv_head * Traits::HEAD_DIM;
-
-    // ---- Load tile lambda: paged addressing ----
-    auto load_tile = [&](int ti, int buf) {
-        int kv0 = ti * Traits::BC;
-        bf16* dK = sK + buf * Traits::BC * Traits::LD;
-        bf16* dV = sV + buf * Traits::BC * Traits::LD;
-        int logical_page = kv0 / p.page_size;
-        int phys_page = p.page_table[batch * p.max_pages + logical_page];
-        bool page_valid = (phys_page >= 0);
-        #pragma unroll
-        for (int i = lane * Traits::VEC; i < Traits::TOTAL;
-             i += Traits::NUM_THREADS * Traits::VEC) {
-            int r = i / Traits::HEAD_DIM, d = i % Traits::HEAD_DIM;
-            int kc = kv0 + r;
-            bool valid = (kc < p.kv_len) && page_valid;
-            int page_off = kc % p.page_size;
-            int64_t gmem_base = (int64_t)phys_page * page_stride
-                              + (int64_t)page_off * pos_stride
-                              + head_off;
-            int off = r * Traits::LD + swiz_col(d, r, Traits::SWIZ_MASK);
-            cp_async_16_pred(&dK[off], &p.k_cache[gmem_base + d], valid);
-            cp_async_16_pred(&dV[off], &p.v_cache[gmem_base + d], valid);
-        }
-        cp_async_commit();
-    };
-
-    constexpr int BUF_MASK = (Traits::STAGES > 1) ? (Traits::STAGES - 1) : 0;
-
-    if (ti_begin < ti_end) {
-        load_tile(ti_begin, 0);
-    }
-
-    for (int ti = ti_begin; ti < ti_end; ti++) {
-        int buf = (ti - ti_begin) & BUF_MASK;
-
-        cp_async_wait_group<0>();
-        __syncwarp();
-        if constexpr (Traits::STAGES > 1) {
-            if (ti + 1 < ti_end)
-                load_tile(ti + 1, (ti + 1 - ti_begin) & BUF_MASK);
-        }
-
-        const bf16* bK = sK + buf * Traits::BC * Traits::LD;
-        const bf16* bV = sV + buf * Traits::BC * Traits::LD;
-        int kv0 = ti * Traits::BC;
-
-        float Sacc[Traits::NC8][4];
-        mma_compute_scores<Traits>(Qa, bK, lane, Sacc);
-
-        #pragma unroll
-        for (int n8 = 0; n8 < Traits::NC8; n8++)
-            Sacc[n8][0] *= p.scale, Sacc[n8][1] *= p.scale,
-            Sacc[n8][2] *= p.scale, Sacc[n8][3] *= p.scale;
-
-        int maxc = IsCausal ? min(p.kv_len, p.causal_offset + 1) : p.kv_len;
-        mma_softmax_tile<Traits, HasMask>(kv0, maxc, maxc,
-                                           0, 0,
-                                           p.mask_b_stride, 0,
-                                           batch,
-                                           p.mask,
-                                           Sacc, Oacc, m0, m1, l0, l1, lane);
-
-        mma_pv_accumulate<Traits>(Sacc, bV, lane, Oacc);
-        __syncwarp();
-
-        if constexpr (Traits::STAGES == 1) {
-            if (ti + 1 < ti_end)
-                load_tile(ti + 1, 0);
-        }
-    }
-
-    auto split_slot = [&](int h) -> size_t {
-        size_t bh = (size_t)batch * p.q_head + h;
-        return bh * MAX_SPLITS + split;
-    };
-    #pragma unroll
-    for (int dn8 = 0; dn8 < Traits::DN8; dn8++) {
-        int d = dn8 * 8 + 2 * tid4;
-        int r0 = gid, r1 = gid + 8;
-        if (r0 < G) {
-            int h = q_head0 + r0;
-            float* op = p.o_part + split_slot(h) * Traits::HEAD_DIM;
-            op[d] = Oacc[dn8][0];
-            op[d + 1] = Oacc[dn8][1];
-        }
-        if (r1 < G) {
-            int h = q_head0 + r1;
-            float* op = p.o_part + split_slot(h) * Traits::HEAD_DIM;
-            op[d] = Oacc[dn8][2];
-            op[d + 1] = Oacc[dn8][3];
-        }
-    }
-    if (tid4 == 0) {
-        int r0 = gid, r1 = gid + 8;
-        if (r0 < G) {
-            int h = q_head0 + r0;
-            float* mp = p.ml_part + split_slot(h) * 2;
-            mp[0] = m0; mp[1] = l0;
-        }
-        if (r1 < G) {
-            int h = q_head0 + r1;
-            float* mp = p.ml_part + split_slot(h) * 2;
-            mp[0] = m1; mp[1] = l1;
-        }
-    }
-}
@@ -1,35 +0,0 @@
-#include "attn_dispatchers.cuh"
-#include "attn_entry_utils.cuh"
-
-torch::Tensor attn_prefill(
-    torch::Tensor q,
-    torch::Tensor k,
-    torch::Tensor v,
-    c10::optional<torch::Tensor> mask,
-    int64_t causal_offset,
-    double scale,
-    int64_t layout
-) {
-    AttentionParams<bf16> p;
-    attn_pack_params(q, k, v, mask, causal_offset, scale, layout, p);
-    TORCH_CHECK(p.head_dim % 16 == 0, "head_dim must be multiple of 16");
-
-    auto O = torch::empty_strided(q.sizes(), q.strides(), q.options());
-    auto O_view = (layout == 1) ? O.transpose(1, 2) : O;
-    p.o = (bf16*)O_view.data_ptr();
-
-    DISPATCH_HEAD_DIM(p.head_dim, dispatch_prefill, p);
-    return O;
-}
-
-PYBIND11_MODULE(TORCH_EXTENSION_NAME, m) {
-    m.def("attn_prefill", &attn_prefill,
-        py::arg("q"),
-        py::arg("k"),
-        py::arg("v"),
-        py::arg("mask") = py::none(),
-        py::arg("causal_offset") = -1,
-        py::arg("scale") = 0.0,
-        py::arg("layout") = 0,
-        "GQA prefill (tensor-core mma on sm_80+, scalar fallback)");
-}
@@ -1,149 +0,0 @@
-#pragma once
-#include <cfloat>
-#include <cuda_bf16.h>
-#include "attn_common.h"
-
-using bf16 = __nv_bfloat16;
-
-// v9: group-split register blocking. G threads cooperate on one query row,
-// each owning HEAD_DIM/G dims of qreg[]/acc[]. IsCausal and HasMask are
-// compile-time bools — the compiler eliminates dead branches.
-// Templated on <HEAD_DIM, G, ROWS, P_BC, IsCausal, HasMask>.
-
-template <int G>
-__device__ __forceinline__ float group_reduce_sum(float v, unsigned mask) {
-#pragma unroll
-    for (int o = G / 2; o > 0; o >>= 1)
-        v += __shfl_xor_sync(mask, v, o);
-    return v;
-}
-
-// load 8 contiguous bf16 from (16-byte aligned) smem as one float4
-__device__ __forceinline__ void ld8(const bf16* p, float* o) {
-    float4 raw = *reinterpret_cast<const float4*>(p);
-    const __nv_bfloat162* h = reinterpret_cast<const __nv_bfloat162*>(&raw);
-#pragma unroll
-    for (int j = 0; j < 4; j++) {
-        float2 f = __bfloat1622float2(h[j]);
-        o[2 * j] = f.x;
-        o[2 * j + 1] = f.y;
-    }
-}
-
-template <int HEAD_DIM, int G, int ROWS, int P_BC, bool IsCausal, bool HasMask>
-__global__ void attn_prefill_split_q_kernel_t(AttentionParams<bf16> p) {
-    constexpr int DPT = HEAD_DIM / G;
-
-    int q_tile = blockIdx.x;
-    int q_head = blockIdx.y;
-    int batch  = blockIdx.z;
-    int gpos   = threadIdx.x;  // 0..G-1  (which d-chunk)
-    int row    = threadIdx.y;  // 0..ROWS-1
-    int q_row  = q_tile * ROWS + row;
-
-    int kv_head = q_head / (p.q_head / p.kv_head);
-
-    __shared__ __align__(16) bf16 sK[P_BC * HEAD_DIM];
-    __shared__ __align__(16) bf16 sV[P_BC * HEAD_DIM];
-
-    // Q: stride-based load [batch, q_head, q_len, head_dim]
-    float qreg[DPT];
-    if (q_row < p.q_len) {
-        int q_off = batch * p.q_stride_b + q_head * p.q_stride_h
-                  + q_row * p.q_stride_l + gpos * DPT * p.q_stride_d;
-#pragma unroll
-        for (int i = 0; i < DPT; i++)
-            qreg[i] = __bfloat162float(p.q[q_off + i * p.q_stride_d]);
-    }
-
-    float m = -FLT_MAX, l = 0.0f;
-    float acc[DPT];
-#pragma unroll
-    for (int i = 0; i < DPT; i++)
-        acc[i] = 0.0f;
-
-    // KV: stride-based base
-    int kv_base = batch * p.kv_stride_b + kv_head * p.kv_stride_h;
-    int mask_batch_base = batch * p.mask_b_stride;
-    int tiles   = (p.kv_len + P_BC - 1) / P_BC;
-    int tt      = G * ROWS;
-    int lid     = row * G + gpos;
-
-    int lane_in_warp = lid & 31;
-    unsigned gmask = (G == 32) ? 0xFFFFFFFFu
-                               : (((1u << G) - 1u) << (lane_in_warp & ~(G - 1)));
-
-    for (int ti = 0; ti < tiles; ti++) {
-        int kv0  = ti * P_BC;
-        int tlen = min(P_BC, p.kv_len - kv0);
-
-        // Load K/V into shared memory from strided global
-        for (int i = lid; i < tlen * HEAD_DIM; i += tt) {
-            int s = i / HEAD_DIM;
-            int d_dim = i % HEAD_DIM;
-            int kv_idx = kv0 + s;
-            int g_off = kv_base + kv_idx * p.kv_stride_l + d_dim * p.kv_stride_d;
-            sK[i] = p.k[g_off];
-            sV[i] = p.v[g_off];
-        }
-        __syncthreads();
-
-        int lim = tlen;
-        if constexpr (IsCausal) {
-            if (q_row < p.q_len) {
-                int ep = q_row + p.causal_offset + 1;
-                if (kv0 >= ep)
-                    lim = 0;
-                else if (kv0 + tlen > ep)
-                    lim = ep - kv0;
-            }
-        }
-
-        int mask_row_base = mask_batch_base + q_row * p.mask_q_stride;
-        for (int s = 0; s < lim; s++) {
-            const bf16* kr = sK + s * HEAD_DIM + gpos * DPT;
-            float part = 0.0f;
-#pragma unroll
-            for (int i = 0; i < DPT; i += 8) {
-                float k8[8];
-                ld8(kr + i, k8);
-#pragma unroll
-                for (int j = 0; j < 8; j++)
-                    part = fmaf(qreg[i + j], k8[j], part);
-            }
-            float dot = group_reduce_sum<G>(part, gmask) * p.scale;
-
-            int kv_idx = kv0 + s;
-            if constexpr (HasMask) {
-                if (!p.mask[mask_row_base + kv_idx])
-                    dot = -FLT_MAX;
-            }
-
-            float nm = fmaxf(m, dot);
-            float al = __expf(m - nm);
-            float be = __expf(dot - nm);
-            l = l * al + be;
-
-            const bf16* vr = sV + s * HEAD_DIM + gpos * DPT;
-#pragma unroll
-            for (int i = 0; i < DPT; i += 8) {
-                float v8[8];
-                ld8(vr + i, v8);
-#pragma unroll
-                for (int j = 0; j < 8; j++)
-                    acc[i + j] = fmaf(v8[j], be, acc[i + j] * al);
-            }
-            m = nm;
-        }
-        __syncthreads();
-    }
-
-    if (q_row < p.q_len) {
-        int o_off = batch * p.q_stride_b + q_head * p.q_stride_h
-                  + q_row * p.q_stride_l + gpos * DPT * p.q_stride_d;
-        float rl = (l > 1e-20f) ? (1.0f / l) : 0.0f;
-#pragma unroll
-        for (int i = 0; i < DPT; i++)
-            p.o[o_off + i * p.q_stride_d] = __float2bfloat16(acc[i] * rl);
-    }
-}
@@ -1,146 +0,0 @@
-#pragma once
-#include <cfloat>
-#include <cuda_bf16.h>
-#include "attn_common.h"
-#include "attn_mma_utils.cuh"
-
-// Tensor-core prefill flash attention (raw mma.sync PTX).
-// One warp owns BR=16 query rows. S = Q@K^T and O = P@V run on bf16 tensor
-// cores via mma.sync.m16n8k16 (f32 accumulate).
-//
-// IsCausal and HasMask are compile-time bools — the compiler eliminates all
-// dead branches in the inner compute loop (FA2-style).
-//
-// Traits = KernelTraits<HEAD_DIM, BC, WARPS=4, STAGES=2>.
-template <typename Traits, bool IsCausal, bool HasMask>
-__global__ void attn_prefill_split_q_mma_kernel(AttentionParams<bf16> p) {
-    const int warp = threadIdx.x / 32;
-    const int lane = threadIdx.x % 32;
-    const int gid = lane >> 2;   // 0..7
-    const int tid4 = lane & 3;   // 0..3
-
-    const int q_head = blockIdx.y;
-    const int batch = blockIdx.z;
-    const int kv_head = q_head / (p.q_head / p.kv_head);
-    const int qrow0 = (blockIdx.x * Traits::WARPS + warp) * Traits::BR;
-
-    // Static shared memory: double-buffered K/V (no sQ — Q goes direct
-    // to registers in mma A-operand layout).
-    __shared__ __align__(16) bf16 sK[Traits::STAGES * Traits::BC * Traits::LD];
-    __shared__ __align__(16) bf16 sV[Traits::STAGES * Traits::BC * Traits::LD];
-
-    // Load Q fragments straight from global into mma A-operand layout.
-    const int q_base = batch * p.q_stride_b + q_head * p.q_stride_h;
-    const int qra = qrow0 + gid;
-    const int qrb = qrow0 + gid + 8;
-    const bool va = qra < p.q_len, vb = qrb < p.q_len;
-    unsigned Qa[Traits::KD][4];
-    load_q_mma_frags<Traits::KD>(p.q + q_base, p.q_stride_l, p.q_stride_d,
-                                  qra, qrb, va, vb, tid4, Qa);
-
-    float Oacc[Traits::DN8][4];
-    #pragma unroll
-    for (int j = 0; j < Traits::DN8; j++)
-        Oacc[j][0] = Oacc[j][1] = Oacc[j][2] = Oacc[j][3] = 0.0f;
-    float m0 = -FLT_MAX, m1 = -FLT_MAX, l0 = 0.0f, l1 = 0.0f;
-
-    // KV: stride-based base
-    const int kv_base = batch * p.kv_stride_b + kv_head * p.kv_stride_h;
-    const int tiles = (p.kv_len + Traits::BC - 1) / Traits::BC;
-    const int qr0 = qrow0 + gid;
-    const int qr1 = qrow0 + gid + 8;
-
-    // Causal tile-skip bounds (dead code when IsCausal == false)
-    const int max_kv = qrow0 + Traits::BR - 1 + p.causal_offset;
-    const int block_max_kv =
-        blockIdx.x * Traits::WARPS * Traits::BR + Traits::WARPS * Traits::BR - 1
-        + p.causal_offset;
-
-    int t_end = tiles - 1;
-    if constexpr (IsCausal) {
-        int bt = block_max_kv / Traits::BC;
-        if (bt < t_end) t_end = bt;
-    }
-
-    // ---- Load tile lambda: predicated cp.async ----
-    auto load_tile = [&](int ti, int buf) {
-        int kv0 = ti * Traits::BC;
-        bf16* dK = sK + buf * Traits::BC * Traits::LD;
-        bf16* dV = sV + buf * Traits::BC * Traits::LD;
-        #pragma unroll
-        for (int i = threadIdx.x * Traits::VEC; i < Traits::TOTAL;
-             i += Traits::NUM_THREADS * Traits::VEC) {
-            int r = i / Traits::HEAD_DIM, d = i % Traits::HEAD_DIM;
-            int kc = kv0 + r;
-            bool valid = kc < p.kv_len;
-            int off = r * Traits::LD + swiz_col(d, r, Traits::SWIZ_MASK);
-            int g_off = kv_base + kc * p.kv_stride_l + d * p.kv_stride_d;
-            cp_async_16_pred(&dK[off], &p.k[g_off], valid);
-            cp_async_16_pred(&dV[off], &p.v[g_off], valid);
-        }
-        cp_async_commit();
-    };
-
-    // ---- Prologue: issue first tile load ----
-    load_tile(0, 0);
-
-    for (int ti = 0; ti <= t_end; ti++) {
-        int buf = ti & 1;
-
-        // Wait for current tile, then publish cross-warp + guard buffer reuse.
-        cp_async_wait_group<0>();
-        __syncthreads();
-        if (ti < t_end) load_tile(ti + 1, (ti + 1) & 1);
-
-        const bf16* bK = sK + buf * Traits::BC * Traits::LD;
-        const bf16* bV = sV + buf * Traits::BC * Traits::LD;
-        int kv0 = ti * Traits::BC;
-
-        // Warp-level causal skip (dead branch eliminated when IsCausal == false)
-        if (!IsCausal || kv0 <= max_kv) {
-
-            float Sacc[Traits::NC8][4];
-            mma_compute_scores<Traits>(Qa, bK, lane, Sacc);
-
-            // Post-multiply scale in float (no bf16 precision loss)
-            #pragma unroll
-            for (int n8 = 0; n8 < Traits::NC8; n8++)
-                Sacc[n8][0] *= p.scale, Sacc[n8][1] *= p.scale,
-                Sacc[n8][2] *= p.scale, Sacc[n8][3] *= p.scale;
-
-            int maxc0 = IsCausal ? min(p.kv_len, qr0 + p.causal_offset + 1)
-                                 : p.kv_len;
-            int maxc1 = IsCausal ? min(p.kv_len, qr1 + p.causal_offset + 1)
-                                 : p.kv_len;
-            mma_softmax_tile<Traits, HasMask>(kv0, maxc0, maxc1,
-                                               qr0, qr1,
-                                               p.mask_b_stride, p.mask_q_stride,
-                                               batch,
-                                               p.mask,
-                                               Sacc, Oacc, m0, m1, l0, l1, lane);
-
-            mma_pv_accumulate<Traits>(Sacc, bV, lane, Oacc);
-        }
-    }
-
-    // ---- write output: packed bf16x2 stores ----
-    float rl0 = (l0 > 1e-20f) ? (1.0f / l0) : 0.0f;
-    float rl1 = (l1 > 1e-20f) ? (1.0f / l1) : 0.0f;
-    const int o_base = batch * p.q_stride_b + q_head * p.q_stride_h;
-    #pragma unroll
-    for (int dn8 = 0; dn8 < Traits::DN8; dn8++) {
-        int d = dn8 * 8 + 2 * tid4;
-        if (qr0 < p.q_len) {
-            __nv_bfloat162 v = __floats2bfloat162_rn(Oacc[dn8][0] * rl0,
-                                                      Oacc[dn8][1] * rl0);
-            *reinterpret_cast<__nv_bfloat162*>(
-                &p.o[o_base + qr0 * p.q_stride_l + d * p.q_stride_d]) = v;
-        }
-        if (qr1 < p.q_len) {
-            __nv_bfloat162 v = __floats2bfloat162_rn(Oacc[dn8][2] * rl1,
-                                                      Oacc[dn8][3] * rl1);
-            *reinterpret_cast<__nv_bfloat162*>(
-                &p.o[o_base + qr1 * p.q_stride_l + d * p.q_stride_d]) = v;
-        }
-    }
-}
@@ -1,13 +0,0 @@
-#pragma once
-#include <cuda_bf16.h>
-
-using bf16 = __nv_bfloat16;
-
-static constexpr int MAX_SPLITS = 32;
-
-__device__ inline float warp_reduce_sum(float val) {
-    #pragma unroll
-    for (int offset = 16; offset > 0; offset >>= 1)
-        val += __shfl_xor_sync(0xFFFFFFFF, val, offset);
-    return val;
-}
@@ -1,185 +0,0 @@
-/*
-Pure-C test — uses shared dispatcher.
-nvcc -I csrc -arch=sm_89 -O3 \
-    --use_fast_math --ptxas-options=-O3 --extra-device-vectorization \
-    csrc/tests/attn_decode_test.cu -o test && ./test
-*/
-
-#include "test_utils.cuh"
-#include "../kernels/attn_dispatchers.cuh"
-
-// Split-K scratch (torch-free)
-struct DecodeScratch {
-    float* o_part = nullptr;
-    float* ml_part = nullptr;
-};
-
-static void setup_scratch(AttentionParams<bf16>& p, DecodeScratch& sc) {
-    int max_splits = 32;
-    cudaMalloc(&sc.o_part, (size_t)p.batch * p.q_head * max_splits * p.head_dim * sizeof(float));
-    cudaMalloc(&sc.ml_part, (size_t)p.batch * p.q_head * max_splits * 2 * sizeof(float));
-}
-
-static void free_scratch(DecodeScratch& sc) {
-    cudaFree(sc.o_part); cudaFree(sc.ml_part);
-}
-
-// Warmed-up, CUDA-event timed sweep over the production decode MMA path.
-static void bench() {
-    const int cfgs[][5] = {
-        {1, 32, 4, 512, 128},
-        {1, 32, 4, 1024, 128},
-        {1, 32, 4, 2048, 128},
-        {1, 32, 4, 4096, 128},
-        {16, 32, 4, 2048, 128},
-        {32, 32, 4, 1024, 128},
-    };
-    const int WARMUP = 10, ITERS = 100;
-    printf("\n===== DECODE BENCH (warmup=%d iters=%d) =====\n", WARMUP, ITERS);
-    print_bench_header();
-
-    for (int ci = 0; ci < 6; ci++) {
-        int B = cfgs[ci][0], Hq = cfgs[ci][1], Hk = cfgs[ci][2];
-        int sl = cfgs[ci][3], D = cfgs[ci][4];
-        size_t nQ = (size_t)B * Hq * D;
-        size_t nKV = (size_t)B * Hk * sl * D;
-
-        bf16 *dQ, *dK, *dV, *dO;
-        cudaMalloc(&dQ, nQ*2); cudaMalloc(&dK, nKV*2);
-        cudaMalloc(&dV, nKV*2); cudaMalloc(&dO, nQ*2);
-        size_t big = nQ > nKV ? nQ : nKV; bf16* tmp = new bf16[big];
-        for (size_t i = 0; i < nQ; i++)  tmp[i] = f2bf(randf());
-        cudaMemcpy(dQ, tmp, nQ*2, cudaMemcpyHostToDevice);
-        for (size_t i = 0; i < nKV; i++) tmp[i] = f2bf(randf());
-        cudaMemcpy(dK, tmp, nKV*2, cudaMemcpyHostToDevice);
-        for (size_t i = 0; i < nKV; i++) tmp[i] = f2bf(randf());
-        cudaMemcpy(dV, tmp, nKV*2, cudaMemcpyHostToDevice);
-        delete[] tmp;
-
-        AttentionParams<bf16> p;
-        p.batch = B; p.q_head = Hq; p.kv_head = Hk; p.q_len = 1; p.kv_len = sl;
-        p.head_dim = D; p.use_mask = 0; p.causal_offset = -1;
-        p.scale = 1.0f / sqrtf((float)D);
-        set_default_strides(p);
-        p.q = dQ; p.k = dK; p.v = dV; p.mask = nullptr; p.o = dO;
-
-        DecodeScratch sc;
-        setup_scratch(p, sc);
-        p.o_part = sc.o_part; p.ml_part = sc.ml_part;
-
-        auto launch = [&]() { dispatch_by_head_dim(D, [&]<int H>() { dispatch_decode<H>(p); }); };
-        double flops = 4.0 * B * Hq * (double)sl * D;
-        double bytes = 2.0 * (2.0 * nKV * sizeof(bf16));
-        BenchResult r = bench_kernel(launch, WARMUP, ITERS, flops, bytes);
-
-        char cfg[64];
-        snprintf(cfg, sizeof(cfg),
-                 "B=%2d Hq=%2d Hk=%d q=%4d kv=%4d D=%3d causal=%d",
-                 B, Hq, Hk, 1, sl, D, 0);
-        print_bench_row(cfg, r);
-
-        cudaFree(dQ); cudaFree(dK); cudaFree(dV); cudaFree(dO);
-        free_scratch(sc);
-    }
-}
-
-static int run_test(int B, int Hq, int Hk, int sl, int D, int causal) {
-    int gs = Hq / Hk;
-    printf("=== B=%d Hq=%d Hk=%d seq=%d D=%d gs=%d causal=%d ===\n",
-           B,Hq,Hk,sl,D,gs,causal);
-
-    size_t nQ = B*Hq*1*D, nKV = B*Hk*sl*D;
-    float *hQ=new float[nQ], *hK=new float[nKV], *hV=new float[nKV];
-    for (size_t i=0;i<nQ;i++) hQ[i]=randf();
-    for (size_t i=0;i<nKV;i++){hK[i]=randf();hV[i]=randf();}
-
-    bool* hMask=new bool[B*sl];
-    for (int i=0;i<B*sl;i++) hMask[i]=true;
-
-    bf16 *dQ,*dK,*dV,*dO,*tmp;
-    bool* dMask;
-    cudaMalloc(&dQ,nQ*2); cudaMalloc(&dK,nKV*2);
-    cudaMalloc(&dV,nKV*2); cudaMalloc(&dO,nQ*2);
-    cudaMalloc(&dMask,B*sl);
-
-    tmp=new bf16[max(nQ,nKV)];
-    for (size_t i=0;i<nQ;i++) tmp[i]=f2bf(hQ[i]);
-    cudaMemcpy(dQ,tmp,nQ*2,cudaMemcpyHostToDevice);
-    for (size_t i=0;i<nKV;i++) tmp[i]=f2bf(hK[i]);
-    cudaMemcpy(dK,tmp,nKV*2,cudaMemcpyHostToDevice);
-    for (size_t i=0;i<nKV;i++) tmp[i]=f2bf(hV[i]);
-    cudaMemcpy(dV,tmp,nKV*2,cudaMemcpyHostToDevice);
-    cudaMemcpy(dMask,hMask,B*sl,cudaMemcpyHostToDevice);
-
-    AttentionParams<bf16> p;
-    p.batch=B; p.q_head=Hq; p.kv_head=Hk; p.q_len=1; p.kv_len=sl; p.head_dim=D;
-    p.use_mask=0; p.causal_offset=causal?0:-1;
-    p.scale=1.0f/sqrtf((float)D);
-    set_default_strides(p);
-    p.q=dQ; p.k=dK; p.v=dV; p.mask=nullptr; p.o=dO;
-
-    DecodeScratch sc;
-    setup_scratch(p, sc);
-    p.o_part = sc.o_part; p.ml_part = sc.ml_part;
-
-    double t0=now_ms();
-    dispatch_by_head_dim(D, [&]<int H>() { dispatch_decode<H>(p); });
-    cudaDeviceSynchronize();
-    double kms=now_ms()-t0;
-    cudaError_t err=cudaGetLastError();
-    if (err!=cudaSuccess){printf("CUDA err: %s\n",cudaGetErrorString(err));return 1;}
-
-    bf16* hOut=new bf16[nQ];
-    cudaMemcpy(hOut,dO,nQ*2,cudaMemcpyDeviceToHost);
-
-    float* ref=new float[nQ];
-    cpu_attention_ref(hQ, hK, hV, hMask, ref, B, Hq, Hk, 1, sl, D, causal ? 0 : -1);
-
-    float max_abs_err=0, max_rel_err=0;
-    for (size_t i=0;i<nQ;i++){
-        float err=fabsf(bf2f(hOut[i])-ref[i]);
-        if(err>max_abs_err) max_abs_err=err;
-        float rel=err/fmaxf(fabsf(ref[i]), 1e-8f);
-        if(rel>max_rel_err) max_rel_err=rel;
-    }
-    const float atol=0.01f, rtol=0.01f;
-    bool pass=true;
-    for (size_t i=0;i<nQ;i++){
-        float err=fabsf(bf2f(hOut[i])-ref[i]);
-        if (err > atol + rtol * fabsf(ref[i])) { pass=false; break; }
-    }
-    printf("kernel: %.3f ms  max_abs_err: %.6e  max_rel_err: %.6e  %s\n\n",
-           kms, max_abs_err, max_rel_err, pass?"PASS":"FAIL");
-
-    cudaFree(dQ);cudaFree(dK);cudaFree(dV);cudaFree(dO);cudaFree(dMask);
-    free_scratch(sc);
-    delete[]hQ;delete[]hK;delete[]hV;delete[]hMask;delete[]hOut;delete[]ref;delete[]tmp;
-
-    return pass ? 0 : 1;
-}
-
-int main() {
-    const int configs[][6] = {
-        {1, 2, 1, 64, 32, 0},
-        {1, 32, 4, 512, 128, 0},
-        {1, 32, 4, 1024, 128, 0},
-        {1, 32, 4, 512, 128, 1},
-    };
-    int n_cfgs = sizeof(configs) / sizeof(configs[0]);
-    int fail = 0;
-
-    for (int ci = 0; ci < n_cfgs; ci++) {
-        int B = configs[ci][0], Hq = configs[ci][1], Hk = configs[ci][2];
-        int sl = configs[ci][3], D = configs[ci][4], causal = configs[ci][5];
-        fail += run_test(B, Hq, Hk, sl, D, causal);
-        if (fail) break;
-    }
-
-    if (fail) {
-        printf("FAILED\n");
-        return fail;
-    }
-    printf("All tests passed!\n");
-    bench();
-    return 0;
-}
@@ -1,308 +0,0 @@
-// Compile:
-//   nvcc -I csrc -arch=sm_89 -O3 --use_fast_math --ptxas-options=-O3 \
-//        --extra-device-vectorization csrc/tests/attn_paged_decode_test.cu \
-//        -o /tmp/test_paged && /tmp/test_paged
-
-#include <cstring>
-#include "test_utils.cuh"
-#include "../kernels/attn_dispatchers.cuh"
-
-static void gather_kv_cpu(
-    const bf16* h_k_pool, const bf16* h_v_pool,
-    const int64_t* h_pt, int B, int Hkv, int kv_len,
-    int page_size, int head_dim,
-    bf16* h_k, bf16* h_v)
-{
-    int max_pages = (kv_len + page_size - 1) / page_size;
-    size_t page_stride = (size_t)page_size * Hkv * head_dim;
-    for (int b = 0; b < B; b++) {
-        for (int pos = 0; pos < kv_len; pos++) {
-            int log_pg = pos / page_size;
-            int pg_off = pos % page_size;
-            int phys = (int)h_pt[b * max_pages + log_pg];
-            for (int h = 0; h < Hkv; h++) {
-                size_t src_base = (size_t)phys * page_stride
-                                + (size_t)pg_off * Hkv * head_dim
-                                + h * head_dim;
-                size_t dst_base = ((size_t)b * Hkv + h) * kv_len * head_dim
-                                  + (size_t)pos * head_dim;
-                memcpy(h_k + dst_base, h_k_pool + src_base, head_dim * sizeof(bf16));
-                memcpy(h_v + dst_base, h_v_pool + src_base, head_dim * sizeof(bf16));
-            }
-        }
-    }
-}
-
-template <int HEAD_DIM>
-static int run_test(int B, int Hq, int Hkv, int kv_len, int page_size, int causal, int seed) {
-    printf("B=%d Hq=%d Hkv=%d kv_len=%d page_sz=%d head_dim=%d causal=%d ... ",
-           B, Hq, Hkv, kv_len, page_size, HEAD_DIM, causal);
-    fflush(stdout);
-
-    int max_pages = (kv_len + page_size - 1) / page_size;
-    int n_phys_pages = B * max_pages;
-    int max_splits = 32;
-
-    size_t sz_q  = (size_t)B * Hq * 1 * HEAD_DIM * sizeof(bf16);
-    size_t sz_o  = sz_q;
-    size_t sz_kv = (size_t)n_phys_pages * page_size * Hkv * HEAD_DIM * sizeof(bf16);
-    size_t sz_pt = (size_t)B * max_pages * sizeof(int64_t);
-    size_t sz_op = (size_t)B * Hq * max_splits * HEAD_DIM * sizeof(float);
-    size_t sz_ml = (size_t)B * Hq * max_splits * 2 * sizeof(float);
-
-    bf16 *d_q, *d_o_paged;
-    bf16 *d_k_pool, *d_v_pool;
-    int64_t* d_pt;
-    float *d_op, *d_ml;
-
-    cudaMalloc(&d_q, sz_q);
-    cudaMalloc(&d_o_paged, sz_o);
-    cudaMalloc(&d_k_pool, sz_kv);
-    cudaMalloc(&d_v_pool, sz_kv);
-    cudaMalloc(&d_pt, sz_pt);
-    cudaMalloc(&d_op, sz_op);
-    cudaMalloc(&d_ml, sz_ml);
-
-    srand(seed);
-    auto rnd = [&]() { return (rand() / (float)RAND_MAX) * 2.0f - 1.0f; };
-
-    bf16* h_q = (bf16*)malloc(sz_q);
-    for (int i = 0; i < B * Hq * HEAD_DIM; i++)
-        h_q[i] = __float2bfloat16(rnd());
-    cudaMemcpy(d_q, h_q, sz_q, cudaMemcpyHostToDevice);
-
-    bf16* h_k_pool = (bf16*)malloc(sz_kv);
-    bf16* h_v_pool = (bf16*)malloc(sz_kv);
-    size_t ps = (size_t)page_size * Hkv * HEAD_DIM;
-    for (int pg = 0; pg < n_phys_pages; pg++) {
-        for (int off = 0; off < page_size; off++) {
-            for (int h = 0; h < Hkv; h++) {
-                for (int d = 0; d < HEAD_DIM; d++) {
-                    float v = sinf((float)(pg * 7919 + off * 1049 + h * 331 + d));
-                    size_t idx = (size_t)pg * ps + (size_t)off * Hkv * HEAD_DIM
-                                 + h * HEAD_DIM + d;
-                    h_k_pool[idx] = __float2bfloat16(v);
-                    h_v_pool[idx] = __float2bfloat16(v * 0.3f);
-                }
-            }
-        }
-    }
-    cudaMemcpy(d_k_pool, h_k_pool, sz_kv, cudaMemcpyHostToDevice);
-    cudaMemcpy(d_v_pool, h_v_pool, sz_kv, cudaMemcpyHostToDevice);
-
-    int64_t* h_pt = (int64_t*)malloc(sz_pt);
-    int next_pg = 0;
-    for (int b = 0; b < B; b++)
-        for (int p = 0; p < max_pages; p++)
-            h_pt[b * max_pages + p] = next_pg++;
-    cudaMemcpy(d_pt, h_pt, sz_pt, cudaMemcpyHostToDevice);
-
-    bf16* h_k_cont = (bf16*)malloc((size_t)B * kv_len * Hkv * HEAD_DIM * sizeof(bf16));
-    bf16* h_v_cont = (bf16*)malloc((size_t)B * kv_len * Hkv * HEAD_DIM * sizeof(bf16));
-    gather_kv_cpu(h_k_pool, h_v_pool, h_pt, B, Hkv, kv_len, page_size, HEAD_DIM, h_k_cont, h_v_cont);
-
-    float* h_q_f = (float*)malloc((size_t)B * Hq * HEAD_DIM * sizeof(float));
-    float* h_k_f = (float*)malloc((size_t)B * kv_len * Hkv * HEAD_DIM * sizeof(float));
-    float* h_v_f = (float*)malloc((size_t)B * kv_len * Hkv * HEAD_DIM * sizeof(float));
-    for (int i = 0; i < B * Hq * HEAD_DIM; i++) h_q_f[i] = bf2f(h_q[i]);
-    for (int i = 0; i < B * kv_len * Hkv * HEAD_DIM; i++) {
-        h_k_f[i] = bf2f(h_k_cont[i]);
-        h_v_f[i] = bf2f(h_v_cont[i]);
-    }
-
-    float* h_o_ref = (float*)calloc(B * Hq * HEAD_DIM, sizeof(float));
-    cpu_attention_ref(h_q_f, h_k_f, h_v_f, nullptr, h_o_ref, B, Hq, Hkv,
-                      1, kv_len, HEAD_DIM, causal ? 0 : -1);
-
-    PagedAttentionParams<bf16> p;
-    p.batch = B; p.q_head = Hq; p.kv_head = Hkv; p.q_len = 1;
-    p.kv_len = kv_len; p.head_dim = HEAD_DIM;
-    p.use_mask = 0; p.causal_offset = causal ? 0 : -1;
-    set_default_paged_strides(p);
-    p.scale = 1.0f / sqrtf((float)HEAD_DIM);
-    p.page_size = page_size; p.max_pages = max_pages;
-    p.page_table = d_pt;
-    p.k_cache = d_k_pool; p.v_cache = d_v_pool;
-    p.q = d_q; p.mask = nullptr; p.o = d_o_paged;
-    p.o_part = d_op; p.ml_part = d_ml;
-
-    dispatch_by_head_dim(HEAD_DIM, [&]<int H>() { dispatch_paged_decode<H>(p); });
-    cudaDeviceSynchronize();
-
-    bf16* h_o_bf16 = (bf16*)malloc(sz_o);
-    cudaMemcpy(h_o_bf16, d_o_paged, sz_o, cudaMemcpyDeviceToHost);
-    float* h_o_paged = (float*)malloc(B * Hq * HEAD_DIM * sizeof(float));
-    for (int i = 0; i < B * Hq * HEAD_DIM; i++)
-        h_o_paged[i] = __bfloat162float(h_o_bf16[i]);
-
-    float max_abs_err = 0.0f, max_rel_err = 0.0f;
-    int bad_idx = -1;
-    for (int i = 0; i < B * Hq * HEAD_DIM; i++) {
-        float e = fabsf(h_o_paged[i] - h_o_ref[i]);
-        if (e > max_abs_err) { max_abs_err = e; bad_idx = i; }
-        float rel = e / fmaxf(fabsf(h_o_ref[i]), 1e-8f);
-        if (rel > max_rel_err) max_rel_err = rel;
-    }
-
-    const float atol = 0.01f, rtol = 0.01f;
-    bool pass = true;
-    for (int i = 0; i < B * Hq * HEAD_DIM; i++) {
-        float e = fabsf(h_o_paged[i] - h_o_ref[i]);
-        if (e > atol + rtol * fabsf(h_o_ref[i])) { pass = false; break; }
-    }
-
-    if (pass) {
-        printf("PASS (max_abs_err=%.4e max_rel_err=%.4e)\n", max_abs_err, max_rel_err);
-    } else {
-        int b = bad_idx / (Hq * HEAD_DIM);
-        int h = (bad_idx / HEAD_DIM) % Hq;
-        int d = bad_idx % HEAD_DIM;
-        printf("FAIL (max_abs_err=%.4e max_rel_err=%.4e at [%d,%d,%d]: ref=%.4f got=%.4f)\n",
-               max_abs_err, max_rel_err, b, h, d, h_o_ref[bad_idx], h_o_paged[bad_idx]);
-        printf("  ref[0..7]:");
-        for (int i = 0; i < 8 && i < HEAD_DIM; i++)
-            printf(" %.4f", h_o_ref[i]);
-        printf("\n  got[0..7]:");
-        for (int i = 0; i < 8 && i < HEAD_DIM; i++)
-            printf(" %.4f", h_o_paged[i]);
-        printf("\n");
-    }
-
-    free(h_q); free(h_k_pool); free(h_v_pool); free(h_pt);
-    free(h_k_cont); free(h_v_cont);
-    free(h_q_f); free(h_k_f); free(h_v_f);
-    free(h_o_ref); free(h_o_bf16); free(h_o_paged);
-    cudaFree(d_q); cudaFree(d_o_paged);
-    cudaFree(d_k_pool); cudaFree(d_v_pool); cudaFree(d_pt);
-    cudaFree(d_op); cudaFree(d_ml);
-
-    return pass ? 0 : 1;
-}
-
-struct TestCase {
-    int head_dim;
-    int B, Hq, Hkv, kv_len, page_size, causal, seed;
-};
-
-static const TestCase TESTS[] = {
-    {128, 1, 1, 1, 8, 128, 0, 1},
-    {128, 1, 4, 4, 128, 128, 0, 2},
-    {128, 2, 4, 4, 256, 128, 0, 3},
-    {128, 1, 4, 1, 64, 64, 0, 4},
-    {128, 1, 8, 2, 64, 128, 0, 5},
-    {128, 2, 16, 4, 128, 128, 0, 6},
-    {64, 1, 4, 2, 32, 128, 0, 7},
-    {256, 1, 2, 1, 16, 128, 0, 8},
-    {32, 1, 4, 2, 32, 64, 0, 9},
-    {128, 3, 8, 2, 256, 128, 0, 10},
-    {128, 2, 32, 8, 512, 128, 0, 11},
-    {128, 1, 16, 2, 256, 128, 0, 12},
-    {128, 2, 32, 4, 512, 128, 0, 13},
-    {128, 2, 8, 2, 128, 128, 1, 14},   // causal
-};
-
-static int dispatch_test(const TestCase& tc) {
-    int r = 0;
-    dispatch_by_head_dim(tc.head_dim, [&]<int D>() {
-        r = run_test<D>(tc.B, tc.Hq, tc.Hkv, tc.kv_len, tc.page_size, tc.causal, tc.seed);
-    });
-    return r;
-}
-
-template <int HEAD_DIM>
-static void bench_config(int B, int Hq, int Hkv, int kv_len, int page_size) {
-    int max_pages = (kv_len + page_size - 1) / page_size;
-    int n_phys_pages = B * max_pages;
-    int max_splits = 32;
-
-    size_t sz_q  = (size_t)B * Hq * 1 * HEAD_DIM * sizeof(bf16);
-    size_t sz_kv = (size_t)n_phys_pages * page_size * Hkv * HEAD_DIM * sizeof(bf16);
-    size_t sz_pt = (size_t)B * max_pages * sizeof(int64_t);
-    size_t sz_op = (size_t)B * Hq * max_splits * HEAD_DIM * sizeof(float);
-    size_t sz_ml = (size_t)B * Hq * max_splits * 2 * sizeof(float);
-
-    bf16 *d_q, *d_o, *d_k_pool, *d_v_pool;
-    int64_t* d_pt;
-    float *d_op, *d_ml;
-    cudaMalloc(&d_q, sz_q); cudaMalloc(&d_o, sz_q);
-    cudaMalloc(&d_k_pool, sz_kv); cudaMalloc(&d_v_pool, sz_kv);
-    cudaMalloc(&d_pt, sz_pt);
-    cudaMalloc(&d_op, sz_op); cudaMalloc(&d_ml, sz_ml);
-
-    bf16* tmp = (bf16*)malloc(sz_kv > sz_q ? sz_kv : sz_q);
-    for (size_t i = 0; i < sz_q / sizeof(bf16); i++) tmp[i] = f2bf(randf());
-    cudaMemcpy(d_q, tmp, sz_q, cudaMemcpyHostToDevice);
-    for (size_t i = 0; i < sz_kv / sizeof(bf16); i++) tmp[i] = f2bf(randf());
-    cudaMemcpy(d_k_pool, tmp, sz_kv, cudaMemcpyHostToDevice);
-    cudaMemcpy(d_v_pool, tmp, sz_kv, cudaMemcpyHostToDevice);
-
-    int64_t* h_pt = (int64_t*)malloc(sz_pt);
-    int next_pg = 0;
-    for (int b = 0; b < B; b++)
-        for (int p = 0; p < max_pages; p++)
-            h_pt[b * max_pages + p] = next_pg++;
-    cudaMemcpy(d_pt, h_pt, sz_pt, cudaMemcpyHostToDevice);
-    free(h_pt);
-
-    PagedAttentionParams<bf16> pa;
-    pa.batch = B; pa.q_head = Hq; pa.kv_head = Hkv; pa.q_len = 1;
-    pa.kv_len = kv_len; pa.head_dim = HEAD_DIM;
-    pa.use_mask = 0; pa.causal_offset = -1;
-    set_default_paged_strides(pa);
-    pa.scale = 1.0f / sqrtf((float)HEAD_DIM);
-    pa.page_size = page_size; pa.max_pages = max_pages;
-    pa.page_table = d_pt;
-    pa.k_cache = d_k_pool; pa.v_cache = d_v_pool;
-    pa.q = d_q; pa.mask = nullptr; pa.o = d_o;
-    pa.o_part = d_op; pa.ml_part = d_ml;
-
-    const int WARMUP = 10, ITERS = 100;
-    auto launch = [&]() {
-        dispatch_by_head_dim(HEAD_DIM, [&]<int H>() { dispatch_paged_decode<H>(pa); });
-    };
-    double flops = 4.0 * B * Hq * (double)kv_len * HEAD_DIM;
-    size_t nKV = (size_t)B * Hkv * kv_len * HEAD_DIM;
-    double bytes = 2.0 * (2.0 * nKV * sizeof(bf16));
-    BenchResult r = bench_kernel(launch, WARMUP, ITERS, flops, bytes);
-
-    char cfg[64];
-    snprintf(cfg, sizeof(cfg),
-             "B=%2d Hq=%2d Hk=%d q=%4d kv=%4d D=%3d page=%3d",
-             B, Hq, Hkv, 1, kv_len, HEAD_DIM, page_size);
-    print_bench_row(cfg, r);
-
-    free(tmp);
-    cudaFree(d_q); cudaFree(d_o);
-    cudaFree(d_k_pool); cudaFree(d_v_pool); cudaFree(d_pt);
-    cudaFree(d_op); cudaFree(d_ml);
-}
-
-static void bench() {
-    printf("\n===== PAGED DECODE BENCH =====\n");
-    print_bench_header();
-    bench_config<128>(1, 32, 4, 512, 128);
-    bench_config<128>(1, 32, 4, 1024, 128);
-    bench_config<128>(1, 32, 4, 2048, 128);
-    bench_config<128>(1, 32, 4, 4096, 128);
-    bench_config<128>(16, 32, 4, 2048, 128);
-    bench_config<128>(32, 32, 4, 1024, 128);
-}
-
-int main() {
-    int n = sizeof(TESTS) / sizeof(TESTS[0]);
-    int fail = 0;
-    printf("=== Paged Decode vs CPU reference (%d cases) ===\n\n", n);
-
-    for (int i = 0; i < n; i++) {
-        fail += dispatch_test(TESTS[i]);
-        if (fail) break;
-    }
-
-    if (fail) {
-        printf("\nFAILED (%d/%d tests failed)\n", fail, n);
-        return fail;
-    }
-    printf("\nAll %d tests passed!\n", n);
-    bench();
-    return 0;
-}
@@ -1,169 +0,0 @@
-/*
-Pure-C test — uses shared dispatcher.
-nvcc -I csrc -arch=sm_89 -O3 \
-    --use_fast_math --ptxas-options=-O3 --extra-device-vectorization \
-    csrc/tests/attn_prefill_test.cu -o test && ./test
-*/
-
-#include "test_utils.cuh"
-#include "../kernels/attn_dispatchers.cuh"
-
-// Warmed-up, CUDA-event timed throughput sweep over the production MMA path.
-static void bench() {
-    const int cfgs[][7] = {
-        {1,32,4,512,512,128,0},
-        {1,32,4,1024,1024,128,0},
-        {1,32,4,2048,2048,128,0},
-        {1,32,4,2048,2048,128,1},
-        {4,32,4,2048,2048,128,1},
-        {1,32,4,4096,4096,128,1},
-    };
-    int n = sizeof(cfgs)/sizeof(cfgs[0]);
-    const int WARMUP = 10, ITERS = 50;
-    printf("\n===== PREFILL BENCH (warmup=%d iters=%d) =====\n", WARMUP, ITERS);
-    printf("%-46s | %10s | %10s | %10s\n",
-           "config", "latency", "bandwidth", "throughput");
-    printf("---------------------------------------------------------------"
-           "----------------------------\n");
-
-    for (int ci = 0; ci < n; ci++) {
-        int B=cfgs[ci][0], Hq=cfgs[ci][1], Hk=cfgs[ci][2];
-        int ql=cfgs[ci][3], kl=cfgs[ci][4], D=cfgs[ci][5], causal=cfgs[ci][6];
-        size_t nQ=(size_t)B*Hq*ql*D, nKV=(size_t)B*Hk*kl*D;
-
-        bf16 *dQ,*dK,*dV,*dO,*tmp;
-        cudaMalloc(&dQ,nQ*2); cudaMalloc(&dK,nKV*2);
-        cudaMalloc(&dV,nKV*2); cudaMalloc(&dO,nQ*2);
-        size_t big = nQ>nKV?nQ:nKV; tmp=new bf16[big];
-        for (size_t i=0;i<nQ;i++)  tmp[i]=f2bf(randf());
-        cudaMemcpy(dQ,tmp,nQ*2,cudaMemcpyHostToDevice);
-        for (size_t i=0;i<nKV;i++) tmp[i]=f2bf(randf());
-        cudaMemcpy(dK,tmp,nKV*2,cudaMemcpyHostToDevice);
-        for (size_t i=0;i<nKV;i++) tmp[i]=f2bf(randf());
-        cudaMemcpy(dV,tmp,nKV*2,cudaMemcpyHostToDevice);
-
-        AttentionParams<bf16> p;
-        p.batch=B; p.q_head=Hq; p.kv_head=Hk; p.q_len=ql; p.kv_len=kl; p.head_dim=D;
-        p.use_mask=0; p.causal_offset=causal?0:-1;
-        set_default_strides(p);
-        p.scale=1.0f/sqrtf((float)D);
-        p.q=dQ; p.k=dK; p.v=dV; p.mask=nullptr; p.o=dO;
-
-        auto launch = [&]() { dispatch_by_head_dim(D, [&]<int H>() { dispatch_prefill<H>(p); }); };
-        for (int i=0;i<WARMUP;i++) launch();
-        cudaDeviceSynchronize();
-        cudaError_t err=cudaGetLastError();
-        if (err!=cudaSuccess){printf("CUDA err: %s\n",cudaGetErrorString(err));return;}
-
-        cudaEvent_t s,e; cudaEventCreate(&s); cudaEventCreate(&e);
-        cudaEventRecord(s);
-        for (int i=0;i<ITERS;i++) launch();
-        cudaEventRecord(e); cudaEventSynchronize(e);
-        float ms=0; cudaEventElapsedTime(&ms,s,e); ms/=ITERS;
-
-        double flops = 4.0*B*Hq*(double)ql*kl*D;
-        if (causal) flops *= 0.5;
-        double tflops = flops/(ms*1e-3)/1e12;
-        double bytes = 2.0 * (2.0*nQ + 2.0*nKV);
-        double gbps = bytes/(ms*1e-3)/1e9;
-
-        char cfg[64];
-        snprintf(cfg, sizeof(cfg),
-                 "B=%2d Hq=%2d Hk=%d q=%4d kv=%4d D=%3d causal=%d",
-                 B,Hq,Hk,ql,kl,D,causal);
-        printf("%-46s | %7.4f ms | %7.1f GB/s | %6.2f TFLOP/s\n",
-               cfg, ms, gbps, tflops);
-
-        cudaFree(dQ);cudaFree(dK);cudaFree(dV);cudaFree(dO);
-        delete[]tmp; cudaEventDestroy(s); cudaEventDestroy(e);
-    }
-}
-
-static int run_test(int B, int Hq, int Hk, int ql, int kl, int D, int causal) {
-    printf("=== B=%d Hq=%d Hk=%d q=%d kv=%d D=%d causal=%d ===\n",
-           B,Hq,Hk,ql,kl,D,causal);
-
-    size_t nQ = B*Hq*ql*D, nKV = B*Hk*kl*D;
-    float *hQ=new float[nQ], *hK=new float[nKV], *hV=new float[nKV];
-    for (size_t i=0;i<nQ;i++) hQ[i]=randf();
-    for (size_t i=0;i<nKV;i++){hK[i]=randf();hV[i]=randf();}
-
-    bf16 *dQ,*dK,*dV,*dO,*tmp;
-    cudaMalloc(&dQ,nQ*2); cudaMalloc(&dK,nKV*2);
-    cudaMalloc(&dV,nKV*2); cudaMalloc(&dO,nQ*2);
-    tmp=new bf16[max(nQ,nKV)];
-    for (size_t i=0;i<nQ;i++) tmp[i]=f2bf(hQ[i]);
-    cudaMemcpy(dQ,tmp,nQ*2,cudaMemcpyHostToDevice);
-    for (size_t i=0;i<nKV;i++) tmp[i]=f2bf(hK[i]);
-    cudaMemcpy(dK,tmp,nKV*2,cudaMemcpyHostToDevice);
-    for (size_t i=0;i<nKV;i++) tmp[i]=f2bf(hV[i]);
-    cudaMemcpy(dV,tmp,nKV*2,cudaMemcpyHostToDevice);
-
-    AttentionParams<bf16> p;
-    p.batch=B; p.q_head=Hq; p.kv_head=Hk; p.q_len=ql; p.kv_len=kl; p.head_dim=D;
-    p.use_mask=0; p.causal_offset=causal?0:-1;
-    set_default_strides(p);
-    p.scale=1.0f/sqrtf((float)D);
-    p.q=dQ; p.k=dK; p.v=dV; p.mask=nullptr; p.o=dO;
-
-    double t0=now_ms();
-    dispatch_by_head_dim(D, [&]<int H>() { dispatch_prefill<H>(p); });
-    cudaDeviceSynchronize();
-    double kms=now_ms()-t0;
-    cudaError_t err=cudaGetLastError();
-    if (err!=cudaSuccess){printf("CUDA err: %s\n",cudaGetErrorString(err));return 1;}
-
-    bf16* hOut=new bf16[nQ];
-    cudaMemcpy(hOut,dO,nQ*2,cudaMemcpyDeviceToHost);
-
-    float* ref=new float[nQ];
-    cpu_attention_ref(hQ, hK, hV, nullptr, ref, B, Hq, Hk, ql, kl, D, causal ? 0 : -1);
-
-    float max_abs_err=0, max_rel_err=0;
-    for (size_t i=0;i<nQ;i++) {
-        float err=fabsf(bf2f(hOut[i])-ref[i]);
-        if(err>max_abs_err) max_abs_err=err;
-        float rel=err/fmaxf(fabsf(ref[i]), 1e-8f);
-        if(rel>max_rel_err) max_rel_err=rel;
-    }
-    const float atol=0.01f, rtol=0.01f;
-    bool pass=true;
-    for (size_t i=0;i<nQ;i++) {
-        float err=fabsf(bf2f(hOut[i])-ref[i]);
-        if (err > atol + rtol * fabsf(ref[i])) { pass=false; break; }
-    }
-    printf("kernel: %.3f ms  max_abs_err: %.6e  max_rel_err: %.6e  %s\n\n",
-           kms, max_abs_err, max_rel_err, pass?"PASS":"FAIL");
-
-    cudaFree(dQ);cudaFree(dK);cudaFree(dV);cudaFree(dO);
-    delete[]hQ;delete[]hK;delete[]hV;delete[]hOut;delete[]ref;delete[]tmp;
-
-    return pass ? 0 : 1;
-}
-
-int main() {
-    const int configs[][7] = {
-        {1,2,1,64,128,64,0},     // tiny: B,Hq,Hk,q,kv,D,causal
-        {1,32,4,512,512,128,0},  // standard
-        {1,32,4,128,256,128,0},  // medium
-        {1,4,2,256,256,128,1},   // causal
-    };
-    int n_configs = sizeof(configs) / sizeof(configs[0]);
-    int fail = 0;
-
-    for (int ci = 0; ci < n_configs; ci++) {
-        int B=configs[ci][0], Hq=configs[ci][1], Hk=configs[ci][2];
-        int ql=configs[ci][3], kl=configs[ci][4], D=configs[ci][5];
-        int causal=configs[ci][6];
-        fail += run_test(B, Hq, Hk, ql, kl, D, causal);
-        if (fail) break;
-    }
-
-    if (fail) {
-        printf("FAILED\n");
-        return fail;
-    }
-    printf("All tests passed!\n");
-    bench();
-    return 0;
-}
@@ -1,171 +0,0 @@
-#pragma once
-
-#include <cstdio>
-#include <cstdlib>
-#include <cmath>
-#include <chrono>
-#include <cuda_bf16.h>
-
-using bf16 = __nv_bfloat16;
-
-inline bf16 f2bf(float x) { return __float2bfloat16(x); }
-inline float bf2f(bf16 x) { return __bfloat162float(x); }
-
-inline float randf() { return (float)rand() / (float)RAND_MAX - 0.5f; }
-
-inline double now_ms() {
-    using namespace std::chrono;
-    return duration_cast<milliseconds>(steady_clock::now().time_since_epoch()).count();
-}
-
-#define CUDA_CHECK(call) \
-    do { \
-        cudaError_t _e = (call); \
-        if (_e != cudaSuccess) { \
-            printf("CUDA error %s at %s:%d\n", cudaGetErrorString(_e), __FILE__, __LINE__); \
-            exit(1); \
-        } \
-    } while (0)
-
-struct BenchResult {
-    float ms;
-    double gbps;
-    double tflops;
-};
-
-template <typename Fn>
-BenchResult bench_kernel(Fn launch, int warmup, int iters,
-                         double flops, double bytes) {
-    for (int i = 0; i < warmup; i++) launch();
-    cudaDeviceSynchronize();
-    cudaError_t err = cudaGetLastError();
-    if (err != cudaSuccess) {
-        printf("CUDA error before bench: %s\n", cudaGetErrorString(err));
-        return {0, 0, 0};
-    }
-
-    cudaEvent_t s, e;
-    cudaEventCreate(&s); cudaEventCreate(&e);
-    cudaEventRecord(s);
-    for (int i = 0; i < iters; i++) launch();
-    cudaEventRecord(e); cudaEventSynchronize(e);
-    float ms = 0; cudaEventElapsedTime(&ms, s, e); ms /= iters;
-    cudaEventDestroy(s); cudaEventDestroy(e);
-
-    return {ms, bytes / (ms * 1e-3) / 1e9, flops / (ms * 1e-3) / 1e12};
-}
-
-inline void print_bench_header() {
-    printf("%-46s | %10s | %10s | %10s\n",
-           "config", "latency", "bandwidth", "throughput");
-    printf("---------------------------------------------------------------"
-           "----------------------------\n");
-}
-
-inline void print_bench_row(const char* cfg, const BenchResult& r) {
-    printf("%-46s | %7.4f ms | %7.1f GB/s | %6.2f TFLOP/s\n",
-           cfg, r.ms, r.gbps, r.tflops);
-}
-
-template <int... Ds>
-struct _HeadSwitch;
-
-template <int D>
-struct _HeadSwitch<D> {
-    template <typename Fn>
-    static void call(int hd, Fn&& fn) { if (hd == D) fn.template operator()<D>(); }
-};
-
-template <int D, int... Rest>
-struct _HeadSwitch<D, Rest...> {
-    template <typename Fn>
-    static void call(int hd, Fn&& fn) {
-        if (hd == D) fn.template operator()<D>();
-        else _HeadSwitch<Rest...>::call(hd, fn);
-    }
-};
-
-// Default set: 32, 64, 128, 256
-template <typename Fn>
-void dispatch_by_head_dim(int head_dim, Fn&& fn) {
-    _HeadSwitch<32, 64, 128, 256>::call(head_dim, fn);
-}
-
-// Set default strides for contiguous b h l d layout on AttentionParams.
-template<typename P>
-inline void set_default_strides(P& p) {
-    p.q_stride_b  = p.q_head * p.q_len * p.head_dim;
-    p.q_stride_h  = p.q_len * p.head_dim;
-    p.q_stride_l  = p.head_dim;
-    p.q_stride_d  = 1;
-    p.kv_stride_b = p.kv_head * p.kv_len * p.head_dim;
-    p.kv_stride_h = p.kv_len * p.head_dim;
-    p.kv_stride_l = p.head_dim;
-    p.kv_stride_d = 1;
-    p.mask_b_stride = p.kv_len;
-    p.mask_q_stride = 0;
-}
-
-// Set default Q strides for contiguous b h l d layout on PagedAttentionParams.
-template<typename P>
-inline void set_default_paged_strides(P& p) {
-    p.q_stride_b  = p.q_head * p.q_len * p.head_dim;
-    p.q_stride_h  = p.q_len * p.head_dim;
-    p.q_stride_l  = p.head_dim;
-    p.q_stride_d  = 1;
-    p.mask_b_stride = p.kv_len;
-    p.mask_q_stride = 0;
-}
-
-// Generic CPU reference for multi-query / grouped-query attention.
-// Tensor shapes (all float*):
-//   Q : [B, Hq, q_len, D]
-//   K : [B, Hk, kv_len, D]
-//   V : [B, Hk, kv_len, D]
-//   O : [B, Hq, q_len, D]
-// mask: if q_len == 1, shape is [B, kv_len]; otherwise mask is not supported.
-// causal_offset: -1 = non-causal; >=0 = absolute position of first Q token.
-static void cpu_attention_ref(
-    const float* Q, const float* K, const float* V, const bool* mask,
-    float* O, int B, int Hq, int Hk, int q_len, int kv_len, int D,
-    int causal_offset
-) {
-    float scale = 1.0f / sqrtf((float)D);
-    int n_rep = Hq / Hk;
-    for (int b = 0; b < B; b++) {
-        for (int h = 0; h < Hq; h++) {
-            int kv_h = h / n_rep;
-            for (int qi = 0; qi < q_len; qi++) {
-                float mv = -INFINITY, sv = 0.0f;
-                float accum[256] = {0.0f};
-                int lim = kv_len;
-                if (causal_offset >= 0) {
-                    int c = qi + causal_offset + 1;
-                    lim = (c < kv_len) ? c : kv_len;
-                }
-                for (int kj = 0; kj < lim; kj++) {
-                    if (mask != nullptr && q_len == 1) {
-                        if (!mask[b * kv_len + kj]) continue;
-                    }
-                    float dot = 0.0f;
-                    size_t q_idx = ((size_t)b * Hq + h) * q_len + qi;
-                    size_t kv_idx = ((size_t)b * Hk + kv_h) * kv_len + kj;
-                    for (int d = 0; d < D; d++)
-                        dot += Q[q_idx * D + d] * K[kv_idx * D + d];
-                    dot *= scale;
-                    float nm = fmaxf(mv, dot);
-                    float a = expf(mv - nm);
-                    float b_exp = expf(dot - nm);
-                    sv = sv * a + b_exp;
-                    for (int d = 0; d < D; d++)
-                        accum[d] = accum[d] * a + V[kv_idx * D + d] * b_exp;
-                    mv = nm;
-                }
-                float inv = 1.0f / sv;
-                size_t o_idx = ((size_t)b * Hq + h) * q_len + qi;
-                for (int d = 0; d < D; d++)
-                    O[o_idx * D + d] = accum[d] * inv;
-            }
-        }
-    }
-}
@@ -9,8 +9,8 @@ readme = "README.md"
 requires-python = ">=3.12"
 dependencies = [
    "h5py==3.15.1",
-    "numpy==2.4.4",
-    "torch==2.11.0",
+    "numpy==2.3.2",
+    "torch==2.7.1",
    "tokenizers==0.21.4",
    "tqdm==4.67.1",
    "safetensors==0.5.3",
@@ -37,7 +37,7 @@ dev = ["pytest==9.0.2", "ruff"]
 where = ["."]

 [tool.pip]
-extra-index-url = "https://download.pytorch.org/whl/cu128"
+extra-index-url = "https://download.pytorch.org/whl/cu126"

 [tool.setuptools.dynamic]
 version = { attr = "astrai.__version__" }
@@ -49,5 +49,4 @@ target-version = "py312"
 quote-style = "double"
 indent-style = "space"
 skip-magic-trailing-comma = false
-line-ending = "auto"
-exclude = ["*.md", "*.json", "*.yml", "*.yaml"]
+line-ending = "auto"
@@ -5,7 +5,7 @@ from huggingface_hub import snapshot_download

 PROJECT_ROOT = Path(__file__).resolve().parents[2]
 DEFAULT_LOCAL_DIR = Path(PROJECT_ROOT, "params")
-DEFAULT_REPO_ID = "ViperEkura/AstrAI-V1-instruct"
+DEFAULT_REPO_ID = "ViperEk/KHAOSZ"

 if __name__ == "__main__":
    parser = argparse.ArgumentParser(
--- a/Show More
+++ b/Show More