yjs

ntirely in TypeScript, which provided 80+ Unix commands (awk, sed, grep, jq, find, sqlite3, curl, etc.) to run against the same data the editor uses. Shell commands and the UI hit the same underlying CRDTs. $ echo "# Meeting notes" > /notes/2026-04-06.md $ mkdir /notes/archive $ mv /notes/2026-04-06.md /notes/archive/ $ open /notes/archive/2026-04-06.md Those commands create and move real files that immediately appear in the editor's file tree. The best part is that all of this works in both browser and server-side contexts, since yjs (https://github.com/yjs/yjs) is isomorphic. Under the hood, metadata (name, parent, timestamps) lives in a versioned CRDT table. Document content lives in a separate Y.Doc per file, so the directory index syncs without pulling every document body. Sync uses the Yjs protocol over WebSocket, with Cloudflare Durable Objects persisting an append-only SQLite update log. Everything is encrypted end-to-end with XChaCha20-Poly1305. Keys derived via HKDF-SHA256; the sync server sees only the ciphertext. More features: CodeMirror 6 with Yjs collaboration binding, `[[` internal links that store file IDs (renames don't break them), SQLite FTS5 search, AI chat with tool-call approval UI, and Vim mode. Opensidian itself is a demo. For the last six months, I've been working on the infrastructure underneath: `@epicenter/workspace` (typed CRDT tables with versioning, migrations, encryption, and sync) and `@epicenter/filesystem` (a POSIX filesystem layer over Yjs). I'll be writing more about those APIs separately and integrating them into more apps in the ecosystem (including Whispering). The idea is that anyone can build local-first apps on the same foundation: notes, task managers, knowledge bases, etc., while solving the most difficult problems of local-first sync. The UI is rough, and the feature set is thin compared to Obsidian; this isn't trying to replace it today. But I'm excited for what the future of personal computing tools could look like! MIT licensed. Would love feedback, ideas, and roasts. Source: https://github.com/EpicenterHQ/epicenter/tree/main/apps/open... Discord: https://go.epicenter.so/discord

. I apologize for being so harsh. I write undo/redo on JS/web quite a lot and this is going down a dark path. Also, you should not put your dist directory in your repo. It should be a deployed artifact connected to a tagged release - or even better keep it in NPM where it belongs.

same final state. This gives you a bunch of cool properties out of the box. Real time support as clients merge concurrent edits from other clients (usually via some central server). Offline support through deterministic merging of offline edits from multiple clients as they reconnect. P2P support because you can send the underlying operations independent of a server and clients can build up the state themselves. If you want to dig deeper there are a bunch of CRDT articles posted to HN. Two that I enjoyed reading are [1] by josephg and [2] by jakelazaroff. CRDTs are also showing up in more software. The Zed editor posted last month uses CRDTs [3] and they have a blog post explaining how it works [4]. Rumor has it that Apple Notes uses CRDTs under the hood. The CRDT library I used is Yjs [5]. If you want to try out TogetherForm for your YC S24 application, this will generate a unique link with the YC application you can share with your co-founder [6]. I'd love to hear any feedback and suggestions you have. I'm also trying to figure out where to focus my time next: a. Build out the no-code form builder. b. Build out a React library (or similar) that allows you to make your forms collaborative by, say, using a special <TogetherForm> component. One last thing: I know it's a lot to trust a random new product, so here's a Google Doc template for the S24 YC application that you can copy and keep for yourself [7]. [1] https://news.ycombinator.com/item?id=31049883 [2] https://news.ycombinator.com/item?id=37764581 [3] https://news.ycombinator.com/item?id=39119835 [4] https://zed.dev/blog/crdts [5] https://github.com/yjs/yjs [6] https://togetherform.com/yc [7] https://docs.google.com/document/d/1zpU14-9zcYGvbxmtLKEbDcsl...