Will It Vibe?Deprecated @app.on_event startup/shutdown hook
Part of Architecture & Best Practices, which counts for 15% of the overall score. When this check fires it deducts 4 points from that category, once per scan, no matter how many places it turns up.
What it detects
@app.on_event('startup'/'shutdown') is deprecated in current FastAPI/Starlette in favor of the lifespan context-manager parameter passed to FastAPI(...), and is scheduled for removal in a future release.
Why it matters
@app.on_event('startup'/'shutdown') is deprecated in current FastAPI and Starlette in favor of the lifespan context-manager parameter, and is scheduled for removal in a future release. Code still relying on it will need to change eventually anyway, and in the meantime a reader has to know both the old and new patterns to understand a codebase that mixes them.
How to fix it
Replace @app.on_event handlers with a single async lifespan context manager passed to FastAPI(lifespan=lifespan): startup code goes before the yield, shutdown code goes after it. This also makes it easier to share state (like a database connection pool) between startup and shutdown without module-level globals.
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