Create a course with two students, the course must have at least one section. Enable completion at site level and course level. Create a mod_lesson activity with at least one content page and without any access restriction Use as completion criteria "Student must view this activity to complete it" Log in as one of the students and visit the lesson activity Log in as teacher and check that the activity is marked as completed by the student and that the student action generated a new entry in the logs (course -> reports -> logs) As admin, enable "Mobile services": Plugins ► Web Services ► Mobile As admin, enable REST protocol: Plugins ► Web Services ► Enable protocols Create a Token for the other student user (the one you didn't used before) Click on Site administration ► Plugins ► Web services ► Manage tokens Next, you can do a CURL REST call simulating a WS client with the student user . You need to replace the wstoken, lessonid (the lesson instance value) and the URL of your moodle instance curl 'http://localhost/m/stable_master/webservice/rest/server.php?moodlewsrestformat=json' --data 'lessonid=2&wsfunction=mod_lesson_view_lesson&wstoken=ffbe3a3002f235bf9d01fd9369e10b66' --compressed Confirm that You can see new entries in the course log (lesson course module viewed) for that course and the user. The origin for the new log entries is "ws" If you access via the web interface you will see the activity marked as completed, if you access the activity via the web interface with the student you will see log entries with origin "web" (lesson course module viewed) NOTE: If you don't see the activity marked as completed you should logout and login again, Moodle session cache sometimes does not upgrade the completion status for activities.