@llui/lexical-collab

Opt-in collaborative editing for the LLui ↔ Lexical binding. It composes @lexical/yjs's CRDT primitives — the same wiring the official React CollaborationPlugin performs — into a single register(editor) step you hand to lexicalForeign (or, more commonly, to the markdown editor's collab option).

The network provider is injected: bring your own y-websocket, y-webrtc, or @hocuspocus/provider. This package never opens a socket itself, so it stays transport-agnostic and ships zero CRDT bytes to non-collaborative bundles (it is a separate, opt-in package).

Why it can't be "just a plugin"

A collaborative session inverts the editor's source of truth: the shared Yjs document — not a markdown string — is canonical. That means the base seam's built-in pieces must be disabled and replaced, which a plain LexicalPlugin cannot do:

• History → @lexical/history's local undo stack would cross peers. Replaced by a Yjs UndoManager scoped to the local origin (your undo only reverts your edits).
• Seed → seeding on every client duplicates content. Replaced by a sync-gated bootstrap: exactly one peer seeds, and only while the shared document is still empty.
• Controlled value → a markdown signal pushing into a CRDT fights convergence. Mutually exclusive with collab.

So @llui/lexical exposes two small, general seam options — history: false and seedMode: 'deferred' — and this package supplies the scoped undo + bootstrap.

Usage with the markdown editor (recommended)

import { mountApp } from '@llui/dom'
import { markdownEditor } from '@llui/markdown-editor'
import { yjsCollab } from '@llui/lexical-collab'
import { Doc } from 'yjs'
import { WebsocketProvider } from 'y-websocket'

const doc = new Doc()

mountApp(
  el,
  markdownEditor({
    defaultValue: '# Shared doc\n\nStart typing…', // becomes the bootstrap seed
    collab: (hooks) =>
      yjsCollab({
        id: 'room-42',
        doc,
        provider: new WebsocketProvider('wss://example.com', 'room-42', doc),
        user: { name: 'Ada', color: '#0a7' },
        shouldBootstrap: true, // exactly one peer should seed
        ...hooks, // seed + onStatus/onSync/onPeers → editor's state.collab
      }),
  }),
)

...hooks forwards the markdown seed (so the bootstrapping peer fills the empty shared doc from defaultValue via the editor's own transformers) and the status sinks (so connection / sync / peer-count flow into state.collab for your chrome).

Usage with the low-level seam

import { lexicalForeign } from '@llui/lexical'
import { yjsCollab } from '@llui/lexical-collab'

const collab = yjsCollab({ id, doc, provider, user, seed })

lexicalForeign({
  namespace: 'doc',
  serialize,
  deserialize,
  readonly,
  history: false, // CRDT undo manager replaces the local stack
  seedMode: 'deferred', // collab bootstrap replaces the boot-time seed
  register: (editor) => collab.register(editor),
})

Presence cursors

Remote carets render automatically when a user is set. @lexical/yjs inline-styles each caret in the peer's colour; this package ships styles/collab.css to position the overlay container:

import '@llui/lexical-collab/styles/collab.css'

Testing your integration

The in-memory networked provider used by this package's own tests connects N peers without a server — useful for asserting convergence in your app's tests. (See test/network.ts.)