Mistral Models via Foundry via Dotnet throw Extra inputs are not permitted due to include_usage

[davidames]

When chatting to any of the Mistral models hosted on Foundry using a Dotnet SDK, you get the following error message when using streaming.

{"error":{"code":"Invalid input","message":"{\"detail\":[{\"type\":\"extra_forbidden\",\"loc\":[\"body\",\"stream_options\",\"include_usage\"],\"msg\":\"Extra inputs are not permitted\",\"input\":true}]}","status":422}}

Tested on

• Semantic Kernel
• M.E.AI
• Azure.AI.OpenAI

All 3 of the above SDKs use the underlying OpenAI.Chat library which hardcodes includeUsage: true as per https://github.com/openai/openai-dotnet/blob/5f13e29de395d2824c0e9c694a4ce5c65edb5392/src/Custom/Chat/ChatClient.cs#L33

Here are the request/response pairs

Endpoint:
POST https://XXXXXXX-int.openai.azure.com/openai/deployments/Mistral-Large-2411/chat/completions?api-version=2025-03-01-preview

Any ideas for how to get around this, or, is there a more appropriate repo to post it to?

[davidames]

The ironic thing is that if you remove include_usage from the request, the model still returns token usage

[amynic]

Hi @davidames - thanks for the detail above - can I ask a couple of clarifying questions below so we know how best to route this discussion?

Was the issue occurring only with Mistral models? (have other models been tested to validates if its the SDK)
Was this tried with more than one Mistral model (example mentions Large + streaming)

[elbruno]

Hi @davidames

Thanks for raising this up. And yes, it's only triggers this error when using Mistral models.
I tested with Mistral-Nemo and Mistral-Large-2411.

It seems to work fine with GPT, DeepSeek and Phi models.

I may suggest you to fill an issue on the official OpenAI client: https://github.com/openai/openai-dotnet/issues

Error, not a fun time 👎

Best

[davidames]

Thanks @elbruno I'm struggling to see how OAI team would care about an issue only affecting 2 Mistral models on Foundry?

Honestly, this feels like a case where Mistral on Foundry is not following Postal's Law.