This looks very promising. But the documentation is not good. I have not managed to find a "1 minute" friendly overview of how it works. I mean, what data gets sent how where and why.
[0] https://github.com/calmh/syncthing/blob/master/protocol/PROT...
The linked website is aimed at end-users.
Try the protocol docs: https://github.com/calmh/syncthing/blob/master/protocol/PROT...