We use auth0-react for our front-end UI and node-auth0 for our back-end. The front-end passes an access token to the back-end to authenticate and authorize any operations.
We only use the session capabilities provided by Auth0 via auth0-react; our system has no separate implementation of “session”.
We would like the back-end to forbid access after a user has logged out.
I’m sorry for the late response. To validate session from the back-channel, our recommended way is to use the GET /api/v2/sessions/{sessionId}Manage User Sessions with Auth0 Management API.
Alternatively, you might find our OIDC Back-Channel Logout feature interesting since it allows your backend to subscribe to logout events. → OIDC Back-Channel Logout