OAuth Logout API

We integrate with OAuth server as the OAuthClient. Users can log on to our service by authenticating with OepnShift OAuth server. User can click logout button from our service web page. But as we do not have a way to log out from Openshift, the session still exists so at the next time the user can automatically logs on from the same browser. What is the URL endpoint call we can make to logout from OpenShift Oauth?