Error codes
| 400 | Invalid body or unavailable model. |
| 401 | Missing or invalid key. |
| 402 | API key budget exhausted. |
| 502 | Upstream failure. |
| 503 | Provider, repository, or capacity unavailable. |
| 400 | Invalid body or unavailable model. |
| 401 | Missing or invalid key. |
| 402 | API key budget exhausted. |
| 502 | Upstream failure. |
| 503 | Provider, repository, or capacity unavailable. |