Heldinhow/python-fastapi

Python FastAPI

Overview

FastAPI is a modern Python web framework for building APIs with automatic documentation. This skill should be invoked when building high-performance APIs that benefit from Python's type hints and FastAPI's automatic validation.

Core Principles

• Type Hints: Leverage Python type hints for validation
• Automatic Docs: OpenAPI/Swagger generated automatically
• Async Support: Native async/await support
• Dependency Injection: Use Depends for clean code

Preparation Checklist

• [ ] Install FastAPI: pip install fastapi
• [ ] Choose ASGI server (Uvicorn, Hypercorn)
• [ ] Plan API structure
• [ ] Define Pydantic models

Step-by-Step Process

1. Install: Add FastAPI and uvicorn
2. Define Models: Create Pydantic models
3. Routes: Add route handlers
4. Validate: Use type hints and Pydantic
5. Document: Access automatic docs at /docs
6. Run: Start with uvicorn

Do's and Don'ts

• ✅ Do use Pydantic for validation
• ✅ Do leverage async for I/O operations
• ✅ Do use dependency injection
• ❌ Don't ignore type hints
• ❌ Don't skip error handling
• ❌ Don't use sync code for DB calls

Anti-Patterns

• No Validation: Skipping Pydantic models
• Sync DB: Using synchronous database calls
• Missing Errors: Not handling HTTP exceptions
• No Docs: Not reviewing automatic docs