### Check for existing issues

- [x] I have searched the existing issues and checked that my issue is not a duplicate.

### What happened?

I'm trying to use liteLLM as backend for claude code, following the documentation [here](https://docs.litellm.ai/docs/tutorials/claude_non_anthropic_models).

LiteLLM has been working great with the desired model for a while, and the setup works using other tools to make the request. However, when I make the requests from claude, I get the following error in claude code:

``` {"error":{"message":"litellm.AuthenticationError: AuthenticationError: OpenAIException - {\n \"error\": {\n \"message\": \"Incorrect API key provided: sk-1234. You can find your API key at https://platform.openai.com/account/api-keys.\",\n \"type\": \"invalid_request_error\",\n \"code\": \"invalid_api_key\",\n \"param\": null\n },\n \"status\": 401\n}. Received Model Group=<model>\nAvailable Model Group Fallbacks=None","type":null,"param":null,"code":"401"} ```

And the following exception in the liteLLM logs:

``` 14:19:58 - LiteLLM Proxy:ERROR: …