Extend Ghost data model with custom resource

Is it possible to extend/add a custom Resource to ghost content and admin APIs. If not, what would you suggest to have it done while not making any changes to the source code itself.

I thought I could add all the new files to a git repo, fetch it and copy the files into ghost, and run ghost-cli update. All this in the docker file.

What exactly do you mean by “a custom Resource”?

Basically a custom entity similar to posts or tags from here https://ghost.org/docs/api/v3/content/#resources