If all of your data is in yjs, then you can use syncedstore to efficiently send updates between clients and y-IndexedDB to store the data when the app is off. I

If all of your data is in yjs, then you can use syncedstore to efficiently send updates between clients and y-IndexedDB to store the data when the app is off. Its not exactly what was asked for, no, but depending on the application that setup can be substituted for a central database.