The WordPress REST API allows you to get data in and out of your WordPress site. There are several built-in REST API methods offered in WordPress, each requiring proper authentication before information is received or distributed. Paid Memberships Pro now includes 7 REST API methods for interacting with your membership site data.
The REST API uses JSON objects to send and receive data in your WordPress site. Check out the REST API Handbook for more information about using this API to interact with your WordPress site.