Consider migrating from httpx to httpx2

[chassing]

Context

lightkube currently depends on httpx[http2] >= 0.28.1, < 1.0.0. The last release of httpx was in December 2024, and the project has become effectively unmaintained — issues and discussions are being closed without resolution.

The Python community is moving to httpx2, which is maintained by Pydantic Services Inc. httpx2 is API-compatible and serves as a drop-in replacement. Major projects like Starlette have already migrated, and others are following suit.

Proposal

Replace the httpx dependency with httpx2 to ensure lightkube continues to receive timely bug fixes and security updates, rather than depending on an unmaintained library.

Notes

• httpx2 is API-compatible with httpx, so the migration should be straightforward
• I'd be happy to submit a PR for this if you're open to the change

Would you be open to this?

[gtsystem]

Hi, this has been on my radar already for some time, but I'm a bit concerned if this change can be considered a breaking change for lightkube users. Some clients may try to catch httpx exceptions (such as TimeoutException) and if we switch to httpx2 the exception classes won't match. I can think about two options here:

1. If httpx is detected as installed in the env, print a warning or fail to start (this will help to capture this type of issue earlier)
2. I was waiting for httpx to have API stability with 1.0 before promoting lightkube as well . Given that httpx2 is now on 2.x, it could be a good time to move to 1.0. This will make the breaking change less concerning as it's a major version increase.
   Do you have any other proposal?

I'll be out next week, but feel free to start testing with httpx2 and prepare a PR if you like. Maybe just the library switch for now, and then we decide which approach to use.

Thanks!