Recap & Practice

What does "idempotent" mean for an HTTP method?

Build a small, multi-file agent registry app combining nearly every concept from this lesson: APIRouter, Pydantic request/response validation, a global exception handler, API key auth via Depends(), a lifespan-initialized shared registry, and a background-logged registration. Fill in every TODO across both files. Every route, dependency, exception handler, and background task function must be declared async def.