Login as admin Create a new course and enrol student Visit the Announcements forum Press Add a new topic Enter Subject & Message and press Post to forum Add a reply to the new discussion Note the discussion ID in your browser URL: ?d=<ID> Create a Token for the student user: Click on Site administration ► Plugins ► Web services ► Manage tokens Enable web services Execute the mod_forum_get_discussion_posts external method simulating a WS client with the student user, substituting your URL, the  <ID> value as appropriate and <WSTOKEN> for student user, e.g.: $ curl -s 'http://localhost/m/stable_master/webservice/rest/server.php?moodlewsrestformat=json' --data 'wsfunction=mod_forum_get_discussion_posts&discussionid=<ID>&wstoken=<WSTOKEN>' | python -m json.tool Confirm each returned post structure in the discussion contains a timemodified property