[paulgb]

Good questions!

> 1

The server keeps the documents in memory when they are open, but it is horizontally scalable by hosting using CloudFlare Durable Objects. (We also plan to support Plane.dev but that's not built out yet).

> 2

The client is based on Yjs, so it's compatible with Yjs' y-indexeddb provider to store in IndexedDB. Tabs synchronize state between each other using a local broadcast channel. The client only synchronizes unsynced state with the server, so if one tab has already pushed the local offline edits to the server, the other tabs can discover that and avoid pushing them. That said, I'm not 100% sure if Yjs deals with the race condition where two tabs wake up at the same time so the server has not yet received offline edits from either, I'd have to check on that.

>3

Yes, Yjs types have an `observe` method that takes a callback, which receives an event with details of each edit. Here’s an example for observing events of a Y.Map: https://docs.yjs.dev/api/shared-types/y.map#observing-change...

[janesconference]

Thanks! Re: 1, the docs are not really deep on that, but from your answer it seems it possible to self-host y-sweet on Cloudflare workers (I guess) with Durable Objects as storage? Also, if you guys are going to have a paid plan, how do you see the prices going? Comparable to, say, Supabase per user, less or more?

[paulgb]

Sorry about that, I’ll clarify the docs. You can self-host on Cloudflare, but the storage is R2/S3/S3-compatible blob storage.

Our tentative pricing is $25/month + $10/10k minutes of “open connection” time (per-document, not per-connection, so multiple users with the same doc open are not double-counted). Storage is free if you bring your own R2/S3 bucket, or a nominal fee if you use ours.

Unlike supabase we don’t do any of the relational stuff, but for Figma-like apps where a lot of documents are never touched, I think our hot/cold storage model can be significantly cheaper at scale than a hosted postgres database like supabase.