Several releases in a row, the latest is 0.161.0, improving support for Pydantic models for forms. fastapi.tiangolo.com/tutoria…

What's new and what's next from Google DeepMind? 🤖 Come and find out with @DynamicWebPaige at FastAPI Conf! 🤓 Join us next week, in Amsterdam, on October 28. 🚲 fastapiconf.com

Optional parameter models in FastAPI 0.159.0 ✨ No dates? No filter. Send either date? Both are required. Make the whole Pydantic model optional while keeping its fields required. Works with query parameters, headers, and cookies. 🚀 fastapi.tiangolo.com/tutoria…

And now in FastAPI 0.158.0, support for multiple form models as well 📋️ fastapi.tiangolo.com/tutoria…

Pagination in one model. Filters in another. Both in the same FastAPI endpoint. ✨ FastAPI 0.157.0 lets you combine multiple query parameter models, alongside individual parameters and dependencies. Works for headers and cookies too. 🚀 fastapi.tiangolo.com/tutoria…

Several more small bug fix releases in a row (5 just today), the lastest is 0.156.8 🚀 github.com/fastapi/fastapi

You can wait for a week or a month, and update to the latest version available then, you would get the same developer experience. And everyone else can benefit from granular releases, where version X might fix something they need, but version X+1 might need more work.

FastAPI 0.156.0 fixes defaults when combining Pydantic Field() with Query(), Body(), and other request parameters. ✨ default_factory and validate_default now work as expected. fastapi.tiangolo.com/release…

FastAPI 0.155.0 removes deprecated extra keyword arguments from request parameters. 🔥 Typos now raise an error instead of silently becoming schema metadata. For custom schema properties, use json_schema_extra. fastapi.tiangolo.com/tutoria…

FastAPI 0.154.0 adds explicit support for Pydantic's validate_default, union_mode, and fail_fast in request parameters. ✨ More control over validation, with editor autocomplete and type checking. fastapi.tiangolo.com/release…

FastAPI 0.153.0 improves browser form handling for unions of Pydantic models. 🐛 Empty inputs, unchecked checkboxes, and unselected files now behave consistently with single form models. fastapi.tiangolo.com/release…

FastAPI 0.152.0 🐛 Validation errors for header parameter models now use the HTTP header name: "save-data" instead of "save_data". Easier to see which header is missing or invalid. ✨ fastapi.tiangolo.com/release…

FastAPI 0.151.0 🐛 Individual Body parameters now distinguish JSON null from missing values. Omit a value to use its default. Send null to get None if the type allows it, or a validation error otherwise. fastapi.tiangolo.com/release…

And one more! 🐛 FastAPI 0.150.0 treats unselected file inputs as missing. Required fields produce validation errors. Fields with defaults use them. Selected empty files still work. ✅ fastapi.tiangolo.com/release…

How many releases can you take in a day? FastAPI 0.149.0 has more form fixes! 🐛 Empty text inputs from browser forms now use defaults. Required fields still produce validation errors. JSON behavior is unchanged. fastapi.tiangolo.com/release…

FastAPI 0.148.0 is out! 🐛 More consistent defaults for query, header, cookie, and form models: * Factories run once * Default fields stay unset * Default validation is opt-in Compatibility notes: fastapi.tiangolo.com/release…

FastAPI 0.147.0 improves HTML checkbox handling ✅ Omitted boolean form fields now become False, even with a True or None default. This matches how browsers handle unchecked checkboxes. Works with form models too. JSON is unchanged. fastapi.tiangolo.com/release…

Breaking change in FastAPI 0.146.0 ⛔️ The root_path parameter is now deprecated in favor of: fastapi run --root-path /your/proxy/path (or equivalents) More in line with the ASGI standard 🤓 fastapi.tiangolo.com/advance…

FastAPI 0.144.0 adds WebSocket support to security dependencies 🔒️ Thanks @usrbinmix ! 🙌 fastapi.tiangolo.com

They just released session management for the Redis SDK for FastAPI 🎉 Wanna learn about it all? Come to FastAPI Conf! Hear it all directly from the source. fastapiconf.com