How should FastAPI lifespan manage application resources?

Uses FastAPI lifespan to create and close process-owned resources around request serving.

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FastAPI lifespan wraps the period when one application process serves requests. Code before yield initializes process-owned resources such as database clients, HTTP clients, or a loaded model; code after yield closes them. I attach only explicitly owned resources to application state or dependencies. Lifespan runs per worker process, so it is not a place for cluster-wide one-time work such as a database migration.

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Uses FastAPI lifespan to create and close process-owned resources around request serving.

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Uses FastAPI lifespan to create and close process-owned resources around request serving.
FastAPI lifespan wraps the period when one application process serves requests. Code before yield initializes process-owned resources such as database clients, HTTP clients, or a loaded model; code after yield closes them. I attach only explicitly owned resources to application state or dependencies. Lifespan runs per worker process, so it is not a place for cluster-wide one-time work such as a database migration.
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Startup should validate critical configuration and establish only the resources required before readiness. Optional dependencies can initialize lazily or expose degraded capability instead of preventing every replica from starting. Cleanup is bounded and resilient because shutdown may have a deadline. Tests enter the lifespan context so they exercise the same initialization and cleanup instead of constructing a half-initialized application.

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Running migrations in every worker lifespan
Opening resources at import time without ownership
Ignoring lifespan in tests

How should FastAPI lifespan manage application resources?

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