by Cesar Zambrano.
hello Jury, I reviewed your old post and not if you've already solved, I developed a new function for web services which returns the list of courses in which a user has the role of editingteacher, this list is returned as a string serialized (json) with the id and the shortname of the course. although it can be modified to return more values.
The service is based on the example and documentation Moodle: https://docs.moodle.org/dev/Adding_a_web_service_to_a_plugin and https://github.com/moodlehq/moodle-local_wstemplate
Deputy .zip service
Sorry for my English