### Check for existing issues

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

### What happened?

I want to proxy a local openai-style model with litellm, and i want to call this model with antrophic-style, i.e. /v1/messages

Normally, litellm should translate **/v1/messages** to **/v1/chat/completions**, but litellm seems to do nothing in translating between them, and i receive a error {"detail":"Not Found"}

### Steps to Reproduce

**LiteLLM Configuration File** ``` model_list: - model_name: Qwen3-32B litellm_params: model: openai/Qwen3-32B api_base: "http://ip:port/v1" api_key: "sk-xx" ``` **Initialization Command** `litellm --config config.yaml --detailed_debug`

**LiteLLM Version** ``` litellm 1.82.3 litellm-enterprise 0.1.39 litellm-proxy-extras 0.4.69 ```

### Relevant log output

```shell POST Request Sent from LiteLLM: curl -X POST \ http://IP:PORT/v1/responses \ -H 'Authorization: Be****h7' \ -d '{'model': 'Qwen3-32B', 'input': [{'type': 'message', 'role': 'user', 'content': [{'type': 'input_text', 'text': 'Hello, can you tell me a short joke?'}]}], '…