Error with OpenAI 1.56.0 - Client.__init__() got an unexpected keyword argument 'proxies'

It is your environment: ill-advised Python 3.13, and deprecated method in the httpx library installed. It is no help that there is no requirements.txt in the python sdk repo, but a requirements.lock file has all pinned versions including the httpx past the deprecation employed.

The cli/_tools/fine_tunes.py hasn’t been touched for over a year. It will reject more valid training file than it would validate at this point.

(edit: the latest OpenAI Python client resolves this issue)