FastAPI Resource Management: Choosing Lifespan over on_event
Learn why the FastAPI lifespan context manager is the preferred choice over deprecated on_event handlers for managing async startup and shutdown resources.
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fastapiFastAPI Lifespan: The Right Way to Share Resources Across Requests
FastAPI's lifespan context manager replaces deprecated on_event handlers for startup/shutdown. Learn how to share a single pooled httpx.AsyncClient across requests, wire it through dependency injection, and avoid common testing pitfalls.
pythonManaging Startup and Shutdown Resources in FastAPI with the Lifespan Event Handler
Learn how FastAPI’s lifespan event handler centralises startup and shutdown logic, with a worked example using a SQLAlchemy async connection pool and notes on version and server requirements.
FastAPI Lifespan vs Legacy Events: Choosing the Right Startup Pattern for Shared Resources
Choose FastAPI's lifespan context manager over legacy on_event handlers for reliable startup/shutdown of database pools, caches, and telemetry. This guide compares mechanisms, shows a production-ready pattern with nested async context managers, and provides validation steps.
Managing App-Lifetime Resources in FastAPI with Lifespan Context Managers
Use FastAPI lifespan context managers to initialize app-scoped resources once at startup and guarantee cleanup on shutdown, exposing them via dependency injection without globals.
FastAPI Lifespan vs on_event: A Practical Decision Guide
Compare FastAPI's lifespan context manager with legacy on_event hooks. Learn how to safely initialize DB pools and shared resources using app.state for better testability and ASGI compliance.
Lifespan context manager shutdown timeout configuration
FastAPI utilizes the lifespan context manager to handle application startup and shutdown logic. This mechanism allows developers to manage resources like database connection pools or HTTP clients across the entire application lifecycle. While the startup phase is straightforward, the shutdown phase lacks a built-in framework constraint to enforce a maximum e
Lifespan Context vs Startup Event: Safe Recovery After a Failed Upgrade
Choosing a Lifecycle Hook for Upgrade Safety When deploying a FastAPI application, a failed upgrade can leave resources—such as database connections or external services—in an inconsistent state. FastAPI exposes two primary mechanisms for initializing and cleaning up resources: the lifespan context manager and the legacy @app.on_event('startup') / @app.on_ev