EDD REST API - Versioning
Since v1.5, Easy Digital Downloads includes a complete RESTful API that allows store data to be retrieved remotely in either a jSON or XML format. The API includes methods for retrieving info about store products, store customers, store sales, and store earnings.
EDD 2.4 introduces API Versioning to allow for adding new functionality while not breaking past functionality for those that need it.
define( 'EDD_API_VERSION', 'v2' );