Access Plugin resources from another application

is there any way to access REST resources provided by an ACE plugin for a another application, e.g. a mobile app or another website? I would like to create pages for a user from my plugin but not from the usual web interface but from another application. So the current workflow would be;

Mobile App -> oAuth login to the confluence instance of the user -> provide some functionality of the confluence plugin

The main problem which I have identified is the authentication against the rest api of the plugin. I have no idea how to do this as I would need to impersonate the confluence instance of the user? You see im quite clueless how this should be done and can be done at all.

Does someone have an idea how this could work or has done or tried something similar?

Thanks in advance for any response!

Have you considered creating a 3LO app? This sounds like it would meet your needs.