thanks.
Though you say easy, Im still failing to bring the pieces together, so would like to bother you once again.
When a user is logged in on the website, the URL that link to the forum site should be set to fourm.example.com/session/sso . Then when a user click this URL to visit forum, he will be logged in to Discourse automatically.
With the current config setup as suggested, the sso_url points to Auth0 and invoking /session/sso brings up the Auth0 login box each time, even for a logged in user?
Also, cant work out what params need to be sent to /session/sso URL?
Regards