Question

How do I detect in devise when the user’s access tokens are stale and thus logging the user out?

Answer 1

Why do you need this? There is timeoutable option exist that allows to track session timeout. I might be wrong, but tokens are cookies keys that have time to live and they are tracked by browser. From Devise (hooks):

Each time a record is set we check whether its session has already timed out
or not, based on last request time. If so, the record is logged out and
redirected to the sign in page. Also, each time the request comes and the
record is set, we set the last request time inside it’s scoped session to
verify timeout in the following request.

—- UPDATE (to not put in commets as its large)—

In the most cases, when you use is logged in, there is no requirements to get authentication from external servises. So in the cases when user is logged in (i.e. session cookie present and session is valid), and in the same time she logs out from external servise that means that she can use your site until your session is expires. Again, the external service is used once user requires authentication. So when session is expired on your site and user trying to log in using external service she will be redirected to external site where she will log in (or not if already). Then external service redirects back to your site provided callback (in the most cases path is /auth/:provider/callback) where your controller (or default provided by devise) will create if required an user and a session for him.