dependency-injection

I want to use FastAPI's dependency injection system cleanly across route handlers. I have database sessions, current user extraction from JWT, and Redis clients that need to be injected. I want to use...

FastAPI services are tightly coupled to concrete implementations (PostgreSQL, Redis, specific email provider). Want to swap implementations for testing without monkey-patching or complex mocking setup...

FastAPI database dependency using SQLAlchemy async session. Need automatic transaction rollback when route handlers raise exceptions, and ensure sessions are always closed without leaking connections....