Web services

How it works

This simple example will give you an idea of how our web services infrastructure works.

1. The client sends a username and password to the web service login script.
2. The script returns a token for that user account.
3. The client calls a particular web service function on a protocol server including the token .
4. The protocol server uses the token to check that the user can call the function.
5. The protocol server calls the matching external function, located in a externallib.php file inside the relevant module.
6. The external function checks that the current user has_capability to do this operation.
7. The external function calls the matching Moodle core function (in lib.php usually).
8. The core function can return a result to the external function.
9. The external function will return a result to the protocol server.
10. The protocol server returns the result to the client.

Developer documentation

The full API can be found on any Moodle sites under Administration block > Plugins > Web services > API Documentation.

Note: Additional services are available for uploading and downloading files which are not in the API Documentation - they are accessed in a different way. See Web services files handling

• How to contribute a web service function to core
• Adding a web service to your plugin
• Implement a web service client
• Web services files handling
• Web service Listing & Roadmap

Specification and brainstorming

• External services security
• External services description

See also

• Web service API functions
• Web services FAQ
• How to create and enable a web service
• How to enable the mobile web service
• Web services user documentation
• Mastering Moodle Web Services development - Last session of the Hackfest in the MoodleMoot UK 2016