Replacing Y.js for realtime collaboration

[ClementEXWiki]

Is your feature request related to a problem? Please describe.
We've had trouble recently finding a good provider for Y.js, due the following reasons:

• HocusPocus seems to have some hard-to-debug problems that we encounter frequently ;
• y-websocket is mostly unmaintained
• y-webrtc is mostly unmaintained
• Liveblocks's server cannot be self-hosted
• etc.

We don't want to use persistent storage, don't want to use S3 or some hosted cloud solution - just a simple, volatile server. And no option seem to work.

Y.js' own documentation does not indicate how to create a provider and has its own set of drawbacks.

Describe the solution you'd like
Allow replacing Y.js with a custom implementation. Just exposing an interface with the required methods for synchronization.

Describe alternatives you've considered
N/A

Additional context
N/A

Bonus
[ ] I'm a sponsor and would appreciate if you could look into this sooner than later 💖

[YousefED]

Hi @ClementEXWiki! Every server has it's own trade-offs - I'd love to to learn more deeply what your requirements are that make none of the existing options a good alternative.

e.g.:

• what are the issues you run into with HocusPocus?
• what are you running into with alternatives such as y-sweet or even a simpler solution like y-websocket? are there other requirements that you think make yjs not a good match?
• do you only want realtime collaboration, or also offline-first mode?
• Are there other methods / servers for prosemirror collaboration you prefer?

We can investigate different approaches for collaboration (e.g. something like prosemirror-collab) of course, but would need to think through the consequences / downsides of this as well. Yjs is widely adopted in the industry and comes with quite some benefitsm but I can see adopting it in an existing system might not always be a good match - so curious to learn more

[ClementEXWiki]

We get a ton of weird bugs that are extremely hard to reproduce with Hocus Pocus. Some events don't fire correctly (e.g. the provider connects to the server but never sends the correct event), sometimes the provider doesn't even connect to the server although it is perfectly reachable in a minimal reproduction example, etc.

The problems I have with y-websocket, y-webrtc and the likes are their maintenance status. They've had dozen of opened issues for years with most not fixed, and there are very few commits currently.

Not sure about the offline-first part, basically if the realtime server is reachable we connect the user to all other players, otherwise it stays entirely offline.

What I think would be interesting would be to make BlockNote expose an API for realtime sync, and an extension that brings Y.js support using that specific API. That way, users who want the most simple pathway can use Y.js using the official extension, and users who want to use another system like AutoMerge can simply bring their own interface.

This would basically make BlockNote indirectly compatible with every single type of realtime syncing mechanism.