Add claude md files (#143)

stack-info: PR: #143, branch: drisspg/stack/12

Author: drisspg

.gitignore

@@ -163,3 +163,6 @@ cython_debug/
 #.idea/
 .vscode
 __pycache__
+
+# Local Claude development notes
+CLAUDE.local.md

CLAUDE.md

@@ -0,0 +1,68 @@
+# Attention Gym - Claude Context
+
+## Repository Overview
+
+Attention Gym is a collection of helpful tools and examples for working with PyTorch's FlexAttention API. This repository provides implementations of various attention mechanisms, performance benchmarks, and utility functions for researchers and developers.
+
+## Project Structure
+
+- `attn_gym/`: Main package containing attention implementations
+  - `masks/`: Examples for creating BlockMasks (causal, sliding window, document masks, etc.)
+  - `mods/`: Examples for creating score_mods (alibi, latent attention, softcapping)
+  - `paged_attention/`: PagedAttention implementations and benchmarks
+- `examples/`: End-to-end implementations and benchmarks
+- `test/`: Test files for the project
+
+## Development Commands
+
+### Setup
+```bash
+# Install in development mode
+pip install -e ".[dev]"
+
+# Install pre-commit hooks
+pre-commit install
+```
+
+### Testing
+```bash
+# Run tests
+pytest
+
+# Run specific test files
+pytest test/test_mods.py
+pytest test/test_natten.py
+```
+
+### Code Quality
+```bash
+# Run linting
+ruff check
+
+# Run formatting
+ruff format
+
+# Run pre-commit on all files
+pre-commit run --all-files
+```
+
+### Running Examples
+```bash
+# Most files can be executed directly
+python attn_gym/masks/document_mask.py
+python examples/benchmark.py
+python examples/mla.py
+```
+
+## Key Dependencies
+
+- PyTorch (>=2.5 for FlexAttention support)
+- Optional: matplotlib, numpy (for visualization examples)
+- Dev: pytest, ruff, pre-commit
+
+## Package Information
+
+- Package name: `attn_gym`
+- Python requirement: >=3.9
+- License: BSD 3-Clause
+- Line length: 99 characters (ruff config)