Backward engineer firefox addon

There is a firefox addon that scrapes certain pages, post information to their server and returns data based on the information on that web page. I want a PHP script that mimics that call, ie calls the addon's server without going through the required pages and returns the available information. The add-on code can be downloaded and the code viewed in order to determine the interface. The requirement is to create a PHP script that mimics the firefox call and returns the required data in a usable format.