As part of the logout process you will want to ensure client applications are informed that the user has signed out.
This is done by sending a notification to and endpoint provided by the each client application. Depending on your architecture, there are three supported techniques to call these endpoints:
Regardless which technique you are using, Duende IdentityServer keeps track of the client applications involved with the current user session and provides helpers and automated ways of invoking the notification mechanisms.
To signout the user from the server-side client applications via the front-channel spec, the “logged out” page in IdentityServer must render an <iframe> for each client that points to the corresponding notification endpoint at the client.
Clients that wish to be notified must have the FrontChannelLogoutUri configuration value set. IdentityServer tracks which clients the user has signed into, and provides an API called GetLogoutContextAsync on the IIdentityServerInteractionService. This API returns a LogoutRequest object with a SignOutIFrameUrl property that your logged out page must render into an <iframe>.
See the Quickstart UI account controller and signout view for an example.
To signout the user from the server-side client applications via the back-channel the IBackChannelLogoutService service can be used. IdentityServer will automatically use this service when your logout page removes the user’s authentication cookie via a call to HttpContext.SignOutAsync.
Clients that wish to be notified must have the BackChannelLogoutUri configuration value set.
There is nothing special you need to do to notify these clients that the user has signed out.