> This guide is only relevant if you are using Unleash Open-Source. The Enterprise edition does already ship with multiple SSO options, such as SAML 2.0, OpenID Connect.
Unleash Open-Source v4 comes with username/password authentication out of the box. In addition Unleash v4 also comes with API token support, to make it easy to handle access tokens for Client SDKs and programmatic access to the Unleash APIs.
To secure the Admin API, you have to tell Unleash that you are using a custom admin authentication and implement your authentication logic as a preHook.
Additionally, you can trigger the admin interface to prompt the user to sign in by configuring your middleware to return a `401` status on protected routes. The response body must contain a `message` and a `path` used to redirect the user to the proper login route.