Progression LIVE now offers a REST / JSON API to create and integration.
This ease the setting up and programming of such an integration by it's greater compatibility with every platforms.
To get access to the REST API and the documentation, got to the Configuration => API tab of your Progression account to generate an API key (do not forget to Save) and go to the URL given to access the test page and the documentation.
Enter the API key previously generated in the user field, without password.
This will bring you to the documentation page that lets you visualise every operation available and their parameters as well as try them in real time.