Create or use a course without groups enabled and more than 5 users enrolled As admin, enable "Mobile services": Plugins ► Web Services ► Mobile Create a Token for one of the users enrolled: 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, courseid and the URL of your moodle instance. curl 'http://localhost/m/stable_master/webservice/rest/server.php?moodlewsrestformat=json' --data 'courseid=4&options%5B0%5D%5Bname%5D=limitfrom&options%5B0%5D%5Bvalue%5D=0&options%5B1%5D%5Bname%5D=limitnumber&options%5B1%5D%5Bvalue%5D=50&moodlewssettingfilter=true&wsfunction=core_enrol_get_enrolled_users&wstoken=ffbe3a3002f235bf9d01fd9369e10b66&options%5B2%5D%5Bname%5D=sortby&options%5B2%5D%5Bvalue%5D=lastname&options%5B3%5D%5Bname%5D=sortdirection&options%5B3%5D%5Bvalue%5D=DESC' --compressed | python -m "json.tool" Confirm that you receive a list of users sorted by lastname DESC (you can | grep fullname to see only relevant information) Modify the lastname and DESC values to order by id, firstname, lastname and siteorder and check that everything works as expected (note, siteorder uses the default Moodle ordering for users so in this case the sort direction in some cases won't be used) Use incorrect values, for example DESCC for sortdirection and idnumber for sortby and check that incorrect parameter errors are returned