### Check for existing issues

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

### What happened?

I am attempting to configure Codex to use LiteLLM as a proxy to DeepSeek due to Codex no longer supporting the chat/completions API. However, when running LiteLLM as a proxy, I obtain the following error:

### Steps to Reproduce

1. Export DeepSeek API key 2. Run LiteLLM: ```litellm --model deepseek/deepseek-v4-pro``` 3. Run Codex and input a command

### Relevant log output

``` {"error":{"message":"litellm.BadRequestError: DeepseekException - {\"error\":{\"message\":\"An assistant message with 'tool_calls' must be followed by tool messages responding to each 'tool_call_id'. (insufficient tool messages following tool_calls message)\",\"type\": \"invalid_request_error\",\"param\":null,\"code\":\"invalid_request_error\"}}","type":null,"param":null,"code":"400"}} ```

### What part of LiteLLM is this about?

_No response_

### What LiteLLM version are you on ?

1.92.0

### Twitter / LinkedIn details

_No response_