A tiny collaborative Markdown editor based on CodeMirror, communicating with a minimal server and database.

Supports multiple real-time documents, with live cursors. Based on CodeMirror's operational transformation extension. All changes are resolved by server code, fully customizable for needs like authentication and rate limiting. Also, it's designed to be as easy to integrate as possible (read: boring). The backend is stateless and even avoids WebSockets by relying on HTTP/2.

Unlike most toy examples, this application persists data and cleans up database memory. Documents are stored in Postgres, and real-time changes are resolved over Redis, with compaction.

An experiment by Eric Zhang.

Requires Docker Compose and Node.js version 18 or higher.

docker compose up

npm install
npm run dev

Visit http://localhost:6480 in your browser.

npm ci
npm run build

export REDIS_URL=redis://...
export DATABASE_URL=postgres://...
npm start

Listens on port 6471 by default, or the PORT environment variable if set.