Sometimes Angular applications are required to authenticate against multiple identity providers. This blog post shows how to implement an Angular SPA which authenticates using Auth0 for one identity provider and also IdentityServer4 from Duende software as the second. The SPA can logout from both of the identity providers individually and also revoke the refresh token used to renew the session using the revocation endpoint. The endsession endpoint is used to logout. IdentityServer4 also supports introspection so that it is possible to revoke reference tokens on a logout as well as the refresh token. The Angular application uses OpenID Connect code flow with PKCE implemented using the npm angular-auth-oidc-client library.