Errors
Status codes are explicit enough for production handling
Use response status plus error_code and request headers to route retries, credit issues, and authentication problems.
200Page fetched and normalized.
400Invalid JSON or unsupported request field value.
401Missing, invalid, or revoked API key.
402Account does not have enough credits.
403Account inactive or paid-plan-only field requested.
409Gateway could not reserve account capacity; retry the request.
413Request body exceeds the 256 KiB public gateway limit.
429Rate limit reached.
502Upstream connection failed.
503Database or upstream worker is not configured.
504Target or worker timed out.