Yjs has a bootstrap problem. To get ot to sync you need to define the root schema and add data, otherwise updates ignore arbitrary keys.

The best way to manage is starting with a raw empty doc, defind all the keys, then update that with a custom blob.

Once you have this doc on your clients, its just a matter of applying the latest updates.

But yeah, Yjs has an eccentric code structure which is impossible to parse without understanding the ops rrquired.

Id look at indexeddb and webrtc plugins

In my case, my problem was wanting to sync key A’s data to/from Alice, and key B’s to/from both Alice and Bob. It was unclear to me where and when to apply which updates involved in the yjs protocols (which i couldn’t find any documentation on).