Great you like the project!
I am also glad you like to develop. In the team, we also considered it an option for the future, to provide different backends for other systems. So maybe we can join forces on this for a consistent solution.
I designed the client software architecture and its protocol. You can contact me by mail (at) michaelzeder.de so we can discuss possibilites.
And as a short overview: Superglue "protocol" is "standard" HTTP 1.1 (GET/POST) plus some "special" URL paths for requesting the server's filesystem operations.