Not quite sure what you are looking for, if it’s a simple way of controlling mopidy or pimusicbox I would use LIRC, I did a walkthrough on setup ages ago here it’s probably out of date by now but might give you an idea of how to.
I have very little programming knowledge and found with lirc I had so much choice as to what it could do quite easily. You can change volume, next, previous and pause, even choose from a preselected up to 10 playlists to play.