FastAPI

FastAPI framework, high performance, easy to learn, fast to code, ready for production. 🚀

Web APIs with Python type hints. 🐍

By @tiangolo 🤓

[FastAPI @FastAPI]

Big news: the first-ever ✨ FastAPI Conf ✨ is coming!

📍 Amsterdam
📅 October 28

Meet the FastAPI team, connect with developers ☕️

🎟️ Join the waitlist for early ticket access: https://t.co/O0gYFWxjHJ

[FastAPI @FastAPI]

If you're using Postgres in Python you're surely using @psycopg, come and chat with the maintainer! 🚀🐘

[Psycopg @psycopg]

Daniele is heading to @FastAPI Conf 2026 in Amsterdam on the 28th October 🚀It’s the first ever official FastAPI conference! Come say hi if you’re there 👋 #FastAPI #Python #PostgreSQL #Psycopg #FastAPIConf #OpenSource

[FastAPI @FastAPI]

Have you missed anything from FastAPI and friends recently? 🕵️

What's there to get excited about in the future? 🤩

@tiangolo will open and close FastAPI Conf: everything we've built so far, and the big plans for the future. 👀

October 28, Amsterdam 🚲

https://t.co/ioc3vjSHvX

[FastAPI @FastAPI]

Who? ☕🌷🚲

[Richard @vanliessum]

So whos excited for @FastAPI conf this week in Amsterdam?

[François Voron @fvoron]

Just rehearsed my @FastAPI Conf talk for my wife. She didn’t understand a word, but she looked proud 😍 So I consider myself ready!

See you next week in Amsterdam 🇳🇱

[FastAPI @FastAPI]

Several releases in a row, the latest is 0.161.0, improving support for Pydantic models for forms.

https://t.co/O3z9ywopHZ

[FastAPI @FastAPI]

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. 🚲

https://t.co/ioc3vjSHvX

[FastAPI @FastAPI]

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. 🚀

https://t.co/sen3LwL7XM

[FastAPI @FastAPI]

And now in FastAPI 0.158.0, support for multiple form models as well 📋️

https://t.co/rGIWxdBcjL

[FastAPI @FastAPI]

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. 🚀

https://t.co/K0bHhRlXkz

[FastAPI @FastAPI]

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. 🚀

https://t.co/K0bHhRlXkz

[FastAPI @FastAPI]

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

https://t.co/LfpZnNfHCr

[FastAPI @FastAPI]

@abhi16_93 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 @FastAPI]

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.

https://t.co/tpZrmBOuiv

[FastAPI @FastAPI]

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.

https://t.co/AvB0x96twh

[FastAPI @FastAPI]

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.

https://t.co/tpZrmBOuiv

[FastAPI @FastAPI]

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.

https://t.co/bQprl3HvLX

[FastAPI @FastAPI]

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. ✨

https://t.co/tpZrmBOuiv

[FastAPI @FastAPI]

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.

https://t.co/tpZrmBNWsX

[FastAPI @FastAPI]

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. ✅

https://t.co/tpZrmBNWsX

[FastAPI @FastAPI]

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.

https://t.co/Lp7abFg6Cf

[FastAPI @FastAPI]

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:
https://t.co/J9ASTZ5Abk