> For AI agents: [llms.txt](https://docs.trustedauth.com/llms.txt) provides a Markdown index of this documentation.

# Authentication and authorization

Use this page to understand how Administration API authentication works before you call protected endpoints. For complete operation details, see the [Administration API reference](/api/admin-api/reference.md).

## Authentication

The Administration API uses an API key security scheme in the `Authorization` header. Authenticate the Admin API application before making other requests, then use the returned token in each protected request.

The authentication response includes the token creation and expiration times:

```json
{
  "authToken": "<admin-api-auth-token>",
  "expirationTime": "2026-08-14T19:07:50.328+0000",
  "creationTime": "2026-08-14T18:52:50.329+0000"
}
```

The raw HTTP examples in [REST examples](/api/admin-api/rest-examples.md) show how to send the `Authorization` header.

Reauthenticate after token expiry

An expired authentication token returns HTTP `401 Unauthorized`. Obtain a new token before retrying the protected request. Applications can track `expirationTime` and reauthenticate before the token expires.

Optional web session cookie

When the authentication request enables a web session, IDaaS also returns an `INTELLITRUST_SESSION_ID` cookie. Include both this cookie and the authentication token in subsequent Administration API requests.

## Contact

For help with Entrust Identity as a Service Administration API integrations, contact <support@entrust.com> or visit [Entrust](https://www.entrust.com/).

## Next steps

- Review [Administration API categories](/api/admin-api/core-concepts/api-categories.md) to find the relevant API operations.
- Use [REST examples](/api/admin-api/rest-examples.md) for raw HTTP request and response examples.
- Use [SDK examples](/api/admin-api/sdk-examples/manage-user.md) if you prefer client libraries.