Real-time collaborative document editor — Google Docs-style editing powered by ProseMirror's operational transformation.

🔗 Live Demo · API Server

• Rich Text Editing — Full formatting with TipTap (bold, italic, headings, lists, links, images)
• Real-time Collaboration — Multiple users editing simultaneously with conflict resolution
• Live Word Count — Character and word statistics updated in real-time
• Persistence — Documents survive server restarts
• Operational Transformation — ProseMirror's battle-tested collab algorithm

• Node.js 18+
• npm or yarn

# Clone the repo
git clone https://github.com/Saumya29/co-write.git
cd co-write

# Start the server
cd server
npm install
npm run dev
# → http://localhost:4000

# Start the client (new terminal)
cd client
npm install
npm run dev
# → http://localhost:3000

Open multiple browser tabs to test collaboration!

co-write/
├── client/                 # React + TipTap frontend
│   ├── src/
│   │   ├── components/     # Editor, Toolbar, MenuBar
│   │   ├── hooks/          # useCollaboration, useEditor
│   │   ├── api/            # Collaboration API client
│   │   └── lib/            # Utilities
│   └── README.md
│
├── server/                 # Express backend
│   ├── src/
│   │   ├── modules/        # Feature modules
│   │   │   └── collaboration/
│   │   ├── routes.ts
│   │   └── index.ts
│   └── data/               # Persistence (state.json)
│
└── README.md

{
  "version": 5,
  "steps": [...],
  "clientID": "abc123"
}

Following ProseMirror's official collab example — HTTP polling is simpler, avoids reconnection complexity, and works well for collaborative editing. The 1-second polling interval provides near-real-time updates. WebSockets can be added later for lower latency.

ProseMirror's OT algorithm handles concurrent edits gracefully. When two users type simultaneously, their changes are transformed to maintain consistency across all clients.

Current: File-based persistence (server/data/state.json) — great for prototypes.

Production path:

• PostgreSQL for ACID transactions and ordered step storage
• Redis for caching recent steps
• Database constraints to enforce step ordering across multiple servers

• TipTap editor with rich text formatting
• Live word/character counter
• ProseMirror collab plugin integration
• Step synchronization between clients
• Document state catch-up on reload
• Debounced step sending (300ms)
• File-based persistence
• Automatic state recovery on startup
• User cursors/presence
• Multiple documents
• User authentication

1. Import repo on vercel.com
2. Set Root Directory to client
3. Set Framework to Vite
4. Add env: VITE_API_URL=https://your-server.railway.app/api

1. Create project on railway.app
2. Connect GitHub repo
3. Set Root Directory to server
4. Build: npm install && npm run build
5. Start: npm start

Built by Saumya Tiwari