Hi @jonriddle - have you checked out the the API documentation in your Admin Gallery? There's examples included there, as well.
I did pour through this documentation. Unfortunately, I don't know how to create the necessary signature for OAuth. I was hoping to find a macro that wrapped all of that up in a nice, neat package for me. I did find this macro (https://gallery.alteryx.com/#!app/OAuth-Login-Macro/58ef72dcf499c713d41edea3), but it appears to only support the Google API's.