--- title: Proxy Provider --- :::info This provider is to be used in conjunction with [Outposts](../outposts/outposts.md) ::: This provider protects applications, which have no built-in support for OAuth2 or SAML. This is done by running a lightweight Reverse Proxy in front of the application, which authenticates the requests. authentik Proxy is based on [oauth2_proxy](https://github.com/oauth2-proxy/oauth2-proxy), but has been integrated more tightly with authentik. The Proxy these extra headers to the application: | Header Name | Value | | ------------------------------ | --------------------------------------------------- | | X-Forwarded-User | The user's unique identifier (**not the username**) | | X-Forwarded-Email | The user's email address | | X-Forwarded-Preferred-Username | The user's username | | X-Auth-Username | The user's username | Additionally, you can add more custom headers using `additionalHeaders` in the User or Group Properties, for example ```yaml additionalHeaders: X-additional-header: bar ```