Endpoints is a Postman library of the endpoints published for IPS 4.
In this version I have only included the GET statements as I wouldn't want any destructive action happen.
To load the JSON file you will need to download Postman - https://www.getpostman.com
Once installed you can setup your own environment with your own API keys or OAuth to your IPS install, once your credentials are setup you will be able to test your API called to your site.
I have also published the endpoints at this location https://documenter.getpostman.com/view/2850550/ips4-get/RVu5iTiR#f2da1a27-2aa1-4321-b9c2-3683ef0e8122
Note: I have yet to finish the Gallery and Calendar - caught a head cold ?