# UnauthorizedResponseError Unauthorized - Authentication required or invalid credentials ## Fields | Field | Type | Required | Description | Example | | ------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------ | | `error` | [components.UnauthorizedResponseErrorData](../components/unauthorizedresponseerrordata.md) | :heavy_check_mark: | Error data for UnauthorizedResponse | {
"code": 401,
"message": "Missing Authentication header"
} | | `openrouter_metadata` | Dict[str, *Nullable[Any]*] | :heavy_minus_sign: | N/A | | | `user_id` | *OptionalNullable[str]* | :heavy_minus_sign: | N/A | |