Claude Code Rules - CLI App

Environment

• Language: Python 3.13+
• UI: Rich (console formatting), prompt-toolkit (interactive input)
• Testing: pytest + pytest-cov
• Linting: Ruff (format + lint)
• Type Checking: mypy (strict mode)
• Package Manager: uv
• Build System: Hatchling

Commands

uv sync                  # Sync/install dependencies
uv tool install .        # Install CLI globally
doit                     # Run the CLI app
uv run pytest            # Run tests
uv run ruff format .     # Format code
uv run ruff check .      # Lint code
uv run mypy .            # Type checking

Structure

• src/doit/ - Main application package
  • app.py - CLI entry point (main())
  • models/ - Data models
    • task.py - Task model
    • exceptions.py - Custom exceptions
  • services/ - Business logic
    • task_service.py - Task operations
  • storage/ - Data persistence
    • memory.py - In-memory storage
    • sqlite.py - SQLite storage
• tests/ - Test suite

Code Standards

• Ruff line length: 100, target Python 3.13.
• Ruff lint rules: E, F, I, N, UP, S, B, A, C4, PT (S101 allowed in tests).
• mypy: strict mode with disallow_untyped_defs.
• Follow TDD: write tests before implementation.
• Place business logic in services/, models in models/, persistence in storage/.
• Entry point: doit.app:main.