| 401 | bad_request | This can happen for a missing API key: {"detail": "API key is required"}, an invalid/expired API key: {"detail": "Invalid or expired API key"} or for other auth parsing errors: {"detail": "<error message>"} |
| 403 | forbidden | API key lacks scope for the path (example: /v1/contents): {"detail": "Missing required scopes"} |
| 404 | agent_not_found or agent_not_supported_yet | The agent ID does not exist (or was deleted), or the agent uses an unsupported model/feature |
| 500 | Internal Server Error (auth/authorization middleware) | This can happen in the case of authentication failure: {"detail": "Internal authentication error"} or authorization failure: {"detail": "Internal authorization error"} |