AttributeError while using HTTP_422_UPROCESSABLE_CONTENT from fastapi.status

[vishds]

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Example Code

from fastapi import status

bla = status.HTTP_422_UNPROCESSABLE_CONTENT

Description

I upgraded my code to use status.HTTP_422_UNPROCESSABLE_CONTENT when I was first hit with AttributeError for status.HTTP_422_UNPROCESSABLE_ENTITY.

I had checked the starlette documentation at that time and I expected FastAPI to pin lower limit of starlette to prevent breaking changes downstream. I got a failure on a machine where starlette 0.47.2 was being used and later found out that it was decided to not to pin the lower limit in #14077.

I have resolved the issue at my end, but I did expect FastAPI to pin the lower limit and not cause issues downstream 😅

Operating System

Linux

Operating System Details

No response

FastAPI Version

0.128.0

Pydantic Version

2.11.7

Python Version

3.13.11

Additional Context

No response

[YuriiMotov]

FastAPI doesn't use neither status.HTTP_422_UNPROCESSABLE_ENTITY nor status.HTTP_422_UNPROCESSABLE_CONTENT internally. So, there is no incompatibility issue on FastAPI's side.

I think you should fix this on your side by pinning the version of Starlette in your application's dependencies

[vishds]

I did the same.
But shouldn't FastAPI pin this since it provides this under fastapi.status.

[YuriiMotov]

I think this is not such strong reason to pin the version.
It's possible that some projects can't upgrade to the latest Starlette version due to other dependencies. If we update the lower pin of Starlette, they will not be able to use latest FastAPI version

[vishds]

It's possible that some projects can't upgrade to the latest Starlette version due to other dependencies.

I understand. Given that I haven't found any other discussions on the topic, I believe this is a more concerning issue than mine.