I’m looking to build an Android app that I can use to communicate with my SmartThings hub. One of my main use cases is being able to initiate device discovery in my Android app (I do NOT want to use the SmartThings app). Is this possible? If so, does SmartThings have an HTTP API reference? (e.g. one that exposes SmartThing resources a la https://developers.soundcloud.com/docs/api/reference)
At this point in time, we do not offer an API endpoint similar to the one you have included with your question. We do have a guide on how to build one.
And a tutorial here
There is a community dashboard app that has an API smartapp
Github Source here
That is not possible at this time; there is no API for Thing discovery & add by third party Apps or services, and no hooks into the SmartThings App.