🐛 mcp-chat: support newer (Azure) OpenAI models

[patrickwyler]

Workspace

mcp-chat

📜 Description

The mcp-chat plugin currently isn't supporting newer (Azure) OpenAI models like gpt-5.1. This newer models might deliver better results, so it would be nice if we could use them. Currently I'm using gpt-4.1-mini which is working fine.

Error message

Unsupported parameter: 'max_tokens' is not supported with this model. Use 'max_completion_tokens' instead.

👍 Expected behavior

Newer Azure OpenAI models like gpt-5.1 are working.

👎 Actual Behavior with Screenshots

Log message

2026-04-02T09:28:02.917Z mcp-chat error [openai] Request failed (400) after 402ms responseData="{\n  \"error\": {\n    \"message\": \"Unsupported parameter: 'max_tokens' is not supported
 with this model. Use 'max_completion_tokens' instead.\",\n    \"type\": \"invalid_request_error\",\n    \"param\": \"max_tokens\",\n    \"code\": \"unsupported_parameter\"\n  }\n}" trace_id="aebfcfd3b54b45df3aac32420d4e5b05" span_id="d9e62c231343bc43" trace_flags="01"

👟 Reproduction steps

1. Configure mcpChat provider

   mcpChat:
     providers:
       - id: openai
         baseUrl: 'https://xxxx-swc-svc.openai.azure.com/openai/v1'
         model: 'xxx-swc-gpt-5.1-2025-11-13-model'
         token: 'xxx'

2. Ask a simple question like 1+1=?

📃 Provide the context for the Bug.

No response

👀 Have you spent some time to check if this bug has been raised before?

• I checked and didn't find similar issue

🏢 Have you read the Code of Conduct?

• I have read the Code of Conduct

Are you willing to submit PR?

None

[patrickwyler]

#7915