OpenRouter Common Errors Overview OpenRouter returns standard HTTP error codes plus OpenRouter-specific error codes in the response body. The most common: 401 (auth), 402 (credits), 429 (rate limit), 400 (bad request), and 5xx (upstream provider errors). Each error includes a field and a human-readable . This skill covers every common error, its root cause, and the exact fix. Complete Error Reference | HTTP | Error Code | Cause | Fix | |------|-----------|-------|-----| | 400 | | Malformed request body | Validate array format; ensure model ID includes provider prefix | | 400 | | Model ID not…