Aww shit! Following up on yesterdays post, there are actually quite a number of optional URL parameters that can be specified when making a HTTP request to the FDFE API. So far, I found:
Their values are configured globally in the playstore app. When set, they are appended to the URL in the order above on every HTTP GET or POST request to the DFE API. The later three take a
false as a value. Not sure what they are suppose to do, though.
I should probably add support for adding arbitrary URL parameters in the coon-mothership library.