Nextcloud integration

Nextcloud has a file manager integration for Nautilus and Dolphin. The integration does two things:

1. It puts an overlay icon on the Nextcloud sync folders and files which indicate the sync status
2. It adds to the right-click menu on files/folders additional menu entries to share files, etc.

I wonder if this would be possible with Thunar as well? Maybe there is even an API (almost) compatible to the one of Nautilus?

I would be interested in looking into it, but first I would like to understand if this is possible at all and if there is some API documentation available.

For reference, this are the current Nextcloud plugins: https://github.com/nextcloud/desktop/tree/master/shell_integration