LLM Errors & Retry: Safe Retry Strategy for the Gateway - APIXO

LLM Gateway calls are direct provider-compatible requests, not async generation tasks. Use the HTTP status code and response body to decide whether to fix the request or retry.

Common errors

Status	Common cause	What to do
`400`	Invalid request body, endpoint, model id, or provider-specific parameter	Fix the request before retrying
`401`	Missing or invalid APIXO API key	Check `APIXO_API_KEY` and the provider-compatible auth header
`403`	Account or key cannot access the requested resource	Check account access, balance, or model availability
`429`	Rate limit, quota limit, or temporary capacity limit	Retry with exponential backoff
`500`	Internal server error	Retry with backoff
`502`	Upstream provider error	Retry with backoff
`504`	Upstream timeout	Retry with backoff or reduce request size

Safe retry policy

Retry only transient failures such as 429, 500, 502, and 504.

1st retry: wait 1 second
2nd retry: wait 2 seconds
3rd retry: wait 4 seconds
then stop or hand off to a queue

Do not blindly retry:

Authentication failures
Invalid JSON or invalid request bodies
Missing required provider headers
Unsupported model names
Requests that already produced a successful streamed response

Debug checklist

Confirm the base URL matches the compatible API.
Confirm the API key is stored as APIXO_API_KEY.
Confirm the model name is supported by that API format.
Test the same request without streaming.
Save the response body and status code before contacting support.

For generation task errors, use the general Error Codes page. This page is focused on direct LLM Gateway calls.