What does 400 unsupported_parameter mean?

You asked for an OpenAI feature the Model API doesn't offer, such as n greater than 1 or logprobs.

Code: unsupported_parameter · HTTP status: 400

Most OpenAI Chat Completions parameters work, but a few are refused instead of being silently ignored.

Common causes#

• n set to 2 or more
• logprobs or top_logprobs

How to fix it#

1. Remove the parameter named in error.param.
2. Need several answers? Send separate requests (mind your key's rate limit).
3. See the full list of supported parameters in the chat completions reference.

Should my code retry?#

Not retryable until you change the request.

The error body uses the OpenAI shape, so OpenAI SDKs raise it as an exception you can catch:

{"error": {"message": "...", "type": "...", "code": "unsupported_parameter", "param": null}}

Every response also carries an X-Request-Id. Keep it in your logs; it's the quickest way for support to find a request.

See the full list in the Model API reference.

Still need help?#

• General support: support@clatterlabs.com or team@clatterlabs.xyz
• Infrastructure questions, or permanent deletion of your data (your whole account or one service): infrastructure@clatterlabs.xyz

We usually reply within the first hour, and always within 24 hours. A full support team is with you.