Fix compatibility with Python 3.14

[medaminezghal]

I think this line from pyproject.toml should be changed from "httpcore==1.*", to "httpcore>=1.0.8", to make sure that it doesn't give problem when import it.

The import problem has been fixed by this commit in version 1.0.8.

[carlwgeorge]

See also #3616

[cclauss]

Tested without success in:

• GitHub Actions: Add Python 3.14 to test matrix #3645

[ilovelinux]

See also:

• Incompatibility with Python 3.14 httpcore#1043

[ilovelinux]

Apparently this has already been fixed. You just need to upgrade the httpcore library to v1.0.8+

See encode/httpcore#1043 (comment)

[cclauss]

Still lingers in both

• GitHub Actions: Add Python 3.14 to test matrix #3645
• Add Python 3.14 to test matrix #3664

https://github.com/encode/httpx/actions/runs/17672966050/job/50228530025#step:4:68 line 67

[ilovelinux]

Can't replicate:

[user@hostname tst]$ uv venv -p 3.14
Using CPython 3.14.0rc3 interpreter at: /home/user/.local/bin/python3.14
Creating virtual environment at: .venv
Activate with: source .venv/bin/activate
[user@hostname tst]$ source .venv/bin/activate
(tst) [user@hostname tst]$ uv pip install httpx
Resolved 7 packages in 9ms
Installed 7 packages in 13ms
 + anyio==4.11.0
 + certifi==2025.10.5
 + h11==0.16.0
 + httpcore==1.0.9
 + httpx==0.28.1
 + idna==3.10
 + sniffio==1.3.1
(tst) [user@hostname tst]$ python
Python 3.14.0rc3 (main, Sep 18 2025, 19:47:22) [Clang 20.1.4 ] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import httpx
>>> 

---

https://github.com/encode/httpx/actions/runs/17672966050/job/50228530025#step:4:68 line 67

It's installing a version that supports Python 3.14. I can't see what's the problem. The job has been cancelled, no errors

[medaminezghal]

@ilovelinux Because the version of httpcore is greater than 1.0.8.

[cclauss]

@ilovelinux uv python install # --> python3..14.0

[ilovelinux]

@ilovelinux Because the version of httpcore is greater than 1.0.8.

Yes, and it is downloaded by default.

I'm not sure pinning the libraries' version with support to the latest Python release is a good practice since it could affect support to older Python versions.

E.g. if I'm using Python 3.10 I can still upgrade httpx without upgrading httpcore. If we pin httpcore to 1.0.8, I couldnt.

AFAIK version pinning should be used for compatibility among libraries, not with Python releases.

If you think I'm wrong, I'm curious about some use-cases or some documentation about this practice 🙁

@ilovelinux uv python install # --> python3..14.0

? You can see from the output that it's Python 3.14

[cclauss]

I saw

[user@hostname tst]$ uv venv -p 3.14
Using CPython 3.14.0rc3 interpreter at: /home/user/.local/bin/python3.14

[medaminezghal]

@ilovelinux httpcore in its latest version should be compatible with python 3.8 and above. Why you can't install httpx when you pin httpcore version?

[cclauss]

• GitHub Actions: Add Python 3.14 to test matrix #3645

tests/test_timeouts.py

@pytest.mark.xfail(sys.version_info >= (3, 14), reason="Fix trio on Python >= 3.14")
async def test_write_timeout(server):