fastapi-backend-guidelines

Structure your FastAPI backend using a three-layer pattern: Router → Service → Repository. This enforces domain-driven design, modular architecture, and async patterns, ensuring consistency across teams.

Manage ORM usage with SQLModel and handle DTO validation via Pydantic. Standardizing these practices ensures consistent data transfer objects and validation across your services, repositories, and routers.

Error handling in a layered FastAPI architecture uses domain exceptions and middleware-based error handling. This standardizes error management across services, repositories, and routers for consistent API responses.

Yes, you can use async/await patterns and dependency injection across all layers in FastAPI. Applying these practices standardizes API design, routing, and service execution for robust backend development.

Yes, these FastAPI backend guidelines enforce SQLModel and SQLAlchemy ORM usage. Applying SQLModel ensures your repository layer maintains standardized async database interactions and DTO validation.