How to handle session inactivity and max timeout in UI?

[akasha2z]

I see that OIDC along with apache is handling inactivity timeout and max session timeout via OIDCSessionInactivityTimeout and OIDCSessionMaxDuration.
But from the UI side, API calls simply start failing with 401 code on reaching timeout.
Is there any indication from mod_auth_openidc to UI that inactivity or max session timeout has reached?
How to handle the timeouts smoothly in UI?

[zandbelt]

see https://github.com/OpenIDC/mod_auth_openidc/wiki/Sessions-and-Timeouts#single-page-applications