fastapi — FixDevsLatest fixes and solutions for fastapi errors on FixDevs.https://fixdevs.com/enThu, 09 Apr 2026 00:00:00 GMTFix: httpx Not Working — Async Client, Timeout, and Connection Pool Errorshttps://fixdevs.com/blog/httpx-not-working/https://fixdevs.com/blog/httpx-not-working/How to fix httpx errors — RuntimeError event loop is closed, ReadTimeout exception, ConnectionResetError, async client not closing properly, HTTP/2 not enabled, SSL verify failed, and proxy not working.Thu, 09 Apr 2026 00:00:00 GMTpythonhttpxasynchttp-clientfastapidebuggingFixDevsFix: Uvicorn Not Working — Worker Errors, Reload Issues, and Production Deploymenthttps://fixdevs.com/blog/uvicorn-not-working/https://fixdevs.com/blog/uvicorn-not-working/How to fix Uvicorn errors — Address already in use port binding, reload not detecting changes, SSL certificate errors, worker class with gunicorn, WebSocket disconnect, graceful shutdown, and proxy headers behind nginx.Thu, 09 Apr 2026 00:00:00 GMTpythonuvicornasgifastapistarlettedeploymentdebuggingFixDevsFix: FastAPI BackgroundTasks Not Working — Task Not Running or Dependency Errorshttps://fixdevs.com/blog/fastapi-background-tasks-not-working/https://fixdevs.com/blog/fastapi-background-tasks-not-working/How to fix FastAPI BackgroundTasks — task not executing, dependency injection in tasks, error handling, Celery for heavy tasks, and lifespan-managed background workers.Wed, 25 Mar 2026 00:00:00 GMTfastapipythonbackenddebuggingFixDevsFix: Pydantic ValidationError — Field Required, Value Not a Valid Type, or Extra Fieldshttps://fixdevs.com/blog/python-pydantic-validation-error/https://fixdevs.com/blog/python-pydantic-validation-error/How to fix Pydantic v2 validation errors — required fields, type coercion, model_validator, custom validators, extra fields config, and migrating from Pydantic v1.Sun, 22 Mar 2026 00:00:00 GMTpythonpydanticfastapibackenddebuggingFixDevsFix: FastAPI Dependency Injection Errors — Dependencies Not Workinghttps://fixdevs.com/blog/fastapi-dependency-injection-error/https://fixdevs.com/blog/fastapi-dependency-injection-error/How to fix FastAPI dependency injection errors — async dependencies, database sessions, sub-dependencies, dependency overrides in tests, and common DI mistakes.Sat, 21 Mar 2026 00:00:00 GMTpythonfastapibackenddebuggingFixDevsFix: Python asyncio Blocking the Event Loop — Mixing Sync and Async Codehttps://fixdevs.com/blog/python-async-sync-mix/https://fixdevs.com/blog/python-async-sync-mix/How to fix Python asyncio event loop blocking — using run_in_executor for sync calls, asyncio.to_thread, avoiding blocking I/O in coroutines, and detecting event loop stalls.Sat, 21 Mar 2026 00:00:00 GMTpythonasynciobackendfastapidebuggingperformanceFixDevsFix: Pydantic ValidationError — Field Required / Value Not Validhttps://fixdevs.com/blog/pydantic-validation-error/https://fixdevs.com/blog/pydantic-validation-error/How to fix Pydantic ValidationError in Python — missing required fields, wrong types, custom validators, handling optional fields, v1 vs v2 API differences, and debugging complex nested models.Thu, 19 Mar 2026 00:00:00 GMTpythonpydanticfastapidebuggingbackendFixDevsFix: FastAPI 422 Unprocessable Entity (validation error)https://fixdevs.com/blog/fastapi-422-unprocessable-entity/https://fixdevs.com/blog/fastapi-422-unprocessable-entity/How to fix FastAPI 422 Unprocessable Entity error caused by wrong request body format, missing fields, type mismatches, query parameter errors, and Pydantic validation.Mon, 09 Mar 2026 00:00:00 GMTpythonfastapidebuggingFixDevs