Stream not supported: fall back to non-streaming

What it means

Either the model does not support streaming, or the middle layer has not implemented it.

{"error":{"message":"This model does not support stream mode"}}

The request asked for a streaming response and the server refused. This is a capability gap, not a rate or balance problem.

Common causes

How to confirm

Turn off stream and send the same request as a non-streaming call. If it succeeds, the model itself is fine. Then check the relay's documentation for whether it supports streaming at all. If official access supports streaming for the same model but the relay does not, the relay is the limitation.

Fix

On your side:

1. Turn off stream and use non-streaming responses.
2. Confirm from the relay's documentation whether streaming is supported.
3. Switch to a channel with a complete implementation.

On the service side:

1. The relay needs to check its forwarding logic.

If it still fails

Non-streaming is the fallback, but the user experience differs a lot. If streaming matters for your product, choose a channel that implements it rather than masking the error.