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:

# schemas.py
from pydantic import BaseModel, EmailStr, field_validator, model_config