Async patterns for FastAPI + SQLAlchemy 2.0

What problem does it solve?

FastAPI applications often struggle with safely creating and disposing database connections in an asynchronous context, leading to leaked connections, inconsistent sessions, and test fragility.

Core Features & Use Cases

• Lifespan-managed engine and per-app session factory to avoid module-level state.
• Repository pattern for clean data access.
• Async testing strategies with fixtures and dependency overrides.
• Guidance on background tasks and proper pool tuning.
• Clear forbidden patterns to avoid anti-patterns.

Quick Start

Wire an async lifespan to create and dispose the engine, expose a session factory via app.state, implement a repository for data access, and adopt the provided testing setup for async code.