FastAPI

When to Use

• Building REST APIs with Python
• Async web applications
• OpenAPI/Swagger documentation needed
• Python microservices
• WebSocket real-time applications

When NOT to Use

• Django projects — use the frameworks/django skill instead
• JavaScript/Node.js backends (Express, NestJS) — this skill is Python-only
• Non-API applications such as CLI tools, desktop apps, or batch processing scripts

Core Patterns