[MISTRAL] ImportError: cannot import name 'UNSET' from 'mistralai'

[pintaf1]

Initial Checks

• I'm using the latest version of Pydantic AI
• I've searched for my issue in the issue tracker before opening this issue

Description

Hello.

When installing pydantic-ai-slim with mistral dependency, we get this error:
ImportError: cannot import name 'UNSET' from 'mistralai'

Mistral has recently deployed a new major version (2.0.x) of their python client.
The issue is not present with pre-2.0.x versions.

Minimal, Reproducible Example

Logfire Trace

No response

Python, Pydantic AI & LLM client version

• Python: 3.21
• Pydantic AI: 1.70.0
• LLM provider SDK: 2.0.x

[navalprakhar]

Confirmed. Tested the 2.0.x releases and every import in models/mistral.py is broken. The last working version is 1.12.4

The quickest fix is probably to cap the dependency to mistralai>=1.9.11,<2.0.0 so fresh installs stop breaking.

For proper 2.0.x support, most of the types still seem to exist, they've just moved from mistralai to mistralai.client/mistralai.client.models, with a few renames. We'd also need to keep 1.x working for backwards compatibility.

@DouweM would you prefer a quick cap to <2.0.0 for now with 2.0.x support as a follow-up, or go straight to adding 2.0.x support? Happy to work on this either way.