{"data":{"slug":"yjs","name":"Yjs","tagline":"MIT CRDT library, not a hosted collab product","category":"comms","categoryName":"Comms","url":"https://github.com/yjs/yjs","github":"https://github.com/yjs/yjs","pricing":"open-source","hook":"Yjs is the CRDT you import. There is no Yjs Cloud, no SKU, no watermark.","whatsGood":"MIT. Shared types for building collaborative software. Pair with Liveblocks if you want rooms hosted, or bring your own provider. Pair with /skills/yjs-best-practices for the library cookbook — this gem is the Catch, not a duplicate skill page.","theCatch":"Not a product. No hosted SKU, no pricing page, no support SLA. You bring the network layer (Liveblocks, y-websocket, your own). Distinct from Socket.IO: CRDT merge, not event fan-out.","verdict":"The MIT CRDT. Pair with Liveblocks for hosted rooms; this is the library, not the meter.","addedAt":"2026-09-03","featured":false,"domain":"Comms","subSpecialty":"Realtime","capabilities":["crdt","realtime"],"surfaces":["Self-host"],"ecosystem":["Browser","Node.js"],"licenseModel":"OSS/MIT","githubStars":22743},"related":[{"slug":"livekit","name":"LiveKit","tagline":"Apache-2.0 realtime rooms, SFU, and agents"},{"slug":"chatwoot","name":"Chatwoot","tagline":"MIT-core support inbox you can self-host for $0/agent"},{"slug":"socket-io","name":"Socket.IO","tagline":"MIT realtime library with fallbacks, not a hosted product"},{"slug":"plunk","name":"Plunk","tagline":"AGPL-3.0 transactional email, workflows, and broadcasts"},{"slug":"centrifugo","name":"Centrifugo","tagline":"Apache-2.0 Go realtime server binary, not in-process Socket.IO"}],"links":{"self":"/api/gems/yjs","html":"/gems/yjs","markdown":"/gems/yjs.md","category":"/api/gems?category=comms","categoryPage":"/stacks/comms"}}