Had a look into this.

I suggest to skip 3.13t which was in beta and not supported by several libraries anyway. For instance, trio only supports 3.14t (and up), and pydantic-core also removed testing for 3.13t .

To be able to run our test suite on 3.14t in the CI, as far as I can see, we'd need

• httptools to release wheels built against Cython 3.1+ (I verified that it installs fine locally)
• pydantic 2.12.0 to be released with 314t wheels
• bcrypt to release 3.14 support -> 5.0.0 is now released with free-threaded Python 3.14 support
• orjson to start supporting free threading (some relevant discussion here)

I'll open a PR to start testing fastapi on (normal) Python 3.14 so we can work on that separately: #14110 #14165

CC @ngoldbaum: as I've seen many contributions from you on various libraries on this topic, does the above ☝️ sound about right? Any other feedback or pointers is appreciated 🙏

does the above ☝️ sound about right? Any other feedback or pointers is appreciated 🙏

httptools isn't a blocker for me personally so I haven't touched it yet. I think it should be straightforward to update if anyone wants to take that on. It'd be really nice to add free-threaded wheel builds to their build automation.

Both pydantic and bcrypt should have releases with 3.14t support soon, I think.

orjson is trickier, I don't think there will be free-threaded support before 3.15. I know that pydatic-core uses https://github.com/pydantic/jiter rather than orjson. I'm not sure how tightly coupled fastapi is to orjson.

📝 Docs preview

Last commit 6a10e4a at: https://778b780b.fastapitiangolo.pages.dev

This pull request has a merge conflict that needs to be resolved.

This PR has gone pretty stale and much has changed since I last worked on it, so I'm continuing this work in #15149.