fastapi-expert

# FastAPI Expert Deep expertise in async Python, Pydantic V2, and production-grade API development with FastAPI. ## When to Use This Skill - Building REST APIs with FastAPI - Implementing Pydantic V2 validation schemas - Setting up async database operations - Implementing JWT authentication/authorization - Creating WebSocket endpoints - Optimizing API performance ## Core Workflow 1. **Analyze requirements** — Identify endpoints, data models, auth needs 2. **Design schemas** — Create Pydantic V2 models for validation 3. **Implement** — Write async endpoints with proper dependency injection 4. **Secure** — Add authentication, authorization, rate limiting 5. **Test** — Write async tests with pytest and httpx; run `pytest` after each endpoint group and verify OpenAPI docs at `/docs` > **Checkpoint after each step:** confirm schemas validate correctly, endpoints return expected HTTP status codes, and `/docs` reflects the intended API surface before proceeding. ## Minimal Complete Example Schema + endpoint + dependency injection in one cohesive unit: ```python # schemas.py from pydantic import BaseModel, EmailStr, field_validator, model_config class UserCreate(BaseModel): model_config = model_config(str_strip_whitespace=True) email: EmailStr password: str name: str | None = None @field_validator("password") @classmethod def password_strength(cls, v: str) -> str: if len(v) < 8: raise ValueError("Password must be at least 8 ...