Real-time Collaborative Code Editor

Minimal full-stack boilerplate for a distraction-free collaborative code editor.

Updated architecture now follows:

• realtime room collaboration over WebSocket
• submit API (/api/submit) to push code execution jobs to an internal queue
• worker pool processing queued jobs
• room-scoped WebSocket fan-out for compile status/output
• MongoDB-backed snippet storage and saved documents

Multi-Service (Docker)

The repo now includes docker-compose.yml for a split backend:

• redis (queue + pub/sub)
• submit-api on 3000
• websocket-server on 5000
• worker (queue consumer + code execution)
• client (Vite) on 5173

Prerequisite on Windows: start Docker Desktop and ensure the Linux engine is running.

Run it:

docker compose up -d --build

Stop services:

docker compose down

Stack

• React + Vite + Tailwind CSS
• Monaco Editor
• Socket.io (client + server)
• Node.js + Express
• MongoDB (Mongoose)

Quick Start

1. Install dependencies:

   npm install
   npm install --workspace client
   npm install --workspace server

2. Configure backend env:
   • Copy server/.env.example to server/.env
   • Set MongoDB and app variables
3. Run both apps:

   npm run dev

Default Endpoints

• Frontend: http://localhost:5173
• Submit API: http://localhost:3000
• WebSocket server: http://localhost:5000
• Compile submit route: POST http://localhost:3000/api/submit
• Save route: POST http://localhost:3000/api/save-to-cloud
• Snippet save route: POST http://localhost:3000/snippets
• Snippet load route: GET http://localhost:3000/snippets/:id
• Snippet delete route: DELETE http://localhost:3000/snippets/:id

Collaboration Events

• join-room
• document-change
• cursor-change
• room-users
• compile-status
• compile-output

Compile Runtime

• CODE_RUNNER_MODE=auto (default): Docker first, local Node fallback for JavaScript
• CODE_RUNNER_MODE=docker: Docker-only execution
• CODE_RUNNER_MODE=local: local Node-only (JavaScript)

Additional server envs:

• WORKER_COUNT (parallel compile workers)
• CODE_TIMEOUT_MS (per submission timeout)

For Docker execution from worker container, Docker socket is mounted in docker-compose.yml.

Note: first run of a language may download Docker images (gcc, python, openjdk, etc.). If your network is slow, first compile can exceed low timeouts. Default timeout is set to 60000ms. Optional warm-up:

docker pull gcc:13 python:3.11 node:20 openjdk:21 golang:1.22 rust:1.77