Errors

The gateway returns OpenAI-style error objects:

{ "error": { "message": "...", "type": "invalid_request_error", "code": "..." } }

Status	Meaning	What to do
400	Invalid request (bad params, malformed body)	Fix the request.
401	Missing / invalid API key	Check the Authorization header.
402	Upstream credit / budget exhausted on a channel	Retry (the gateway shifts channels); contact us if persistent.
404	Unknown model or path	Verify the model ID and endpoint.
413	Payload too large	Reduce input size.
429	Rate limited or over budget	Back off and retry; see Rate limits.
5xx	Transient upstream / gateway error	Retry with backoff; the gateway auto-fails-over across channels.

Recommended client behaviour

• Implement exponential backoff on 429 and 5xx.
• Treat 402 as transient — multi-channel HA usually recovers on retry.
• Surface 400/404 to developers (they indicate a request bug, not a transient fault).