# unauthenticated

> The unauthenticated Problem Details code: The Authorization header is missing, or its key or token is unknown, revoked or of the wrong kind.

Source: https://docs.nexafone.so/v1/errors/unauthenticated/

| | |
| --- | --- |
| HTTP status | `401` |
| Area | General |
| Problem `type` | `https://docs.nexafone.so/errors/unauthenticated` |

The `Authorization` header is missing, or its key or token is unknown, revoked or of the wrong kind. Check that you send `Authorization: Bearer <key>` with a live key of the right workspace; an SDK session token that expired needs a refresh.

## Handling it

Check the credential: send a valid, unrevoked key or a fresh token.

## Example

```json
{
  "type": "https://docs.nexafone.so/errors/unauthenticated",
  "title": "Unauthorized",
  "status": 401,
  "code": "unauthenticated",
  "detail": "A human-readable explanation of this occurrence.",
  "requestId": "01J9Z8Q4TQ3W6M5V2X7Y8Z9A0B"
}
```

Match on `code`, never on `detail`: the wording may change. See [Problem Details](/v1/errors/).