@absolutejs/sync-yjs

A Yjs-backed collaborative-text CRDT for @absolutejs/sync, behind the same CrdtText / TextCrdtAdapter contract as the core's zero-dependency rgaText.

@absolutejs/sync/crdt ships a first-party RGA text CRDT that's great for offline-merge and moderate collaboration. When you need production-scale collaborative text — efficient deltas, no unbounded tombstone growth, the interleaving guarantees the community relies on — Yjs is the staple. This adapter lets you swap it in without touching your call sites.

Install

bun add @absolutejs/sync-yjs yjs

@absolutejs/sync is a peer dependency (you already have it). yjs is a runtime dependency you install alongside.

Use

import { yjsText } from '@absolutejs/sync-yjs';
// ...instead of: import { rgaText } from '@absolutejs/sync/crdt';

// Client — a live doc per replica (e.g. per tab/device)
const doc = yjsText.create('tab-a', initialStateFromServer);
doc.setText(textarea.value); // reconciles via a minimal diff
socket.send(doc.state()); // broadcast the serialized (base64) state
doc.merge(incomingState); // fold a peer's state into local edits
doc.text(); // the merged visible text

// Server — merge-on-write so concurrent writes combine instead of clobbering
const next = yjsText.merge(storedState, incomingState);
// store `next`; yjsText.textOf(next) is the plain text

The serialized state is a base64 string of a Yjs update — JSON-safe for the sync engine's change feed and for storing as a row field. merge is commutative/associative/idempotent, so the order writes arrive in doesn't matter.

The contract

This package implements TextCrdtAdapter<string> from @absolutejs/sync/crdt:

| Member | What it does | | --------------------------- | ------------------------------------------------------------- | | create(replica, initial?) | A live CrdtText doc: text/setText/merge/state. | | merge(a, b) | Combine two persisted states (server-side, no live instance). | | empty() | The serialized state of an empty document. | | textOf(state) | The plain text of a persisted state. |

License

CC BY-NC 4.0