Sync Code — Realtime Collaborative Code Editor

A modern, real-time collaborative code editor built as a TypeScript monorepo using pnpm workspaces and Turborepo. Features CRDT-based conflict-free document synchronization, multi-file project workspaces, live video/audio calling, session recording & replay, AI pair programming, and a shared collaborative whiteboard.

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Features

• Realtime CRDT Collaboration — Powered by Yjs and Hocuspocus for conflict-free document sync across multiple clients with no merge conflicts.
• Multi-file Project Workspace — File tree with real-time CRUD, tab switching, CodeMirror 6 editor with syntax highlighting for 20+ languages, and ZIP import/export.
• Presence & Cursor Tracking — Live avatar badges showing active users and which files they're editing.
• Realtime Text Chat — Markdown message rendering, @username mention notifications, and chat history backfill on join.
• LiveKit Audio & Video Calls — SFU-based video/voice chat, screen sharing, and participant controls powered by LiveKit.
• Session Recording & Replay — Capture canvas recordings as .webm video and replay with interactive scrubber and playback speed controls (1×, 2×, 4×).
• AI Pair Programmer — Code explanation, refactoring, bug fixes, and custom generation with one-click editor insertion. Supports Anthropic and OpenAI providers.
• Collaborative Whiteboard — Shared real-time canvas with pencil, rectangle, circle, and text tools, color palette, and PNG export.
• Admin Controls — Room host can mute/unmute and remove participants.
• Snapshot & Persistence — Background CRDT state snapshotting with database persistence.
• JWT Authentication — Token-based session management.
• Dark Mode — Toggle between dark and light editor themes.

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Tech Stack

Layer	Technology
Frontend	React 18, TypeScript, Vite, Tailwind CSS, CodeMirror 6, Zustand
Backend API	NestJS 10, Socket.IO, TypeScript
CRDT Server	Hocuspocus (Yjs), WebSocket
Video/Audio	LiveKit (SFU), @livekit/components-react
AI	Anthropic Claude, OpenAI (configurable)
Database	PostgreSQL
Cache	Redis
Object Storage	MinIO (local) / S3 / R2 (production)
Monorepo	pnpm workspaces, Turborepo
Testing	Vitest

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Monorepo Structure

code-editor/
├── apps/
│   ├── client/            React 18 + Vite + Tailwind CSS + CodeMirror 6
│   ├── api/               NestJS — REST API, Auth, Chat, AI proxy, LiveKit tokens
│   └── collab/            Hocuspocus (Yjs) CRDT document sync server
├── packages/
│   ├── shared-types/      Shared TypeScript DTOs, socket event contracts, schemas
│   └── ui/                Shared React component primitives & panel designs
├── infra/
│   └── docker-compose.yml PostgreSQL, Redis, MinIO, LiveKit orchestration
└── legacy/                Preserved original CRA + Express codebase (reference only)

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Prerequisites

• Node.js v18.0.0 or higher
• pnpm v9.0.0 or higher — install with npm i -g pnpm
• Docker & Docker Compose (optional — for the full containerized stack)

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Quick Start

1. Clone & Install

git clone https://github.com/Mohitur669/Realtime-Collaborative-Code-Editor.git
cd Realtime-Collaborative-Code-Editor
pnpm install

2. Configure Environment

cp .env.example .env

Edit .env and fill in the required values:

Variable	Description
DATABASE_URL	PostgreSQL connection string
REDIS_URL	Redis connection string
JWT_SECRET	Secret for JWT token signing
AI_DEFAULT_PROVIDER	anthropic or openai
ANTHROPIC_API_KEY	Anthropic API key (if using Claude)
OPENAI_API_KEY	OpenAI API key (if using GPT)
LIVEKIT_API_KEY	LiveKit API key
LIVEKIT_API_SECRET	LiveKit API secret
S3_ACCESS_KEY	MinIO / S3 access key
S3_SECRET_KEY	MinIO / S3 secret key

3. Start Development Servers

pnpm dev

This starts all three services simultaneously via Turborepo:

Service	URL
Client App	http://localhost:5173
NestJS API	http://localhost:3001
Collab CRDT Server	ws://localhost:1234
LiveKit SFU	ws://localhost:7880

Open http://localhost:5173 to create or join a collaboration room.

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Development Commands

Command	Description
pnpm dev	Start all dev servers (client + api + collab)
pnpm build	Build all packages and apps for production
pnpm test	Run all unit and integration tests
pnpm lint	Lint all packages
pnpm format	Format all files with Prettier
pnpm --filter @codesync/client dev	Start only the client
pnpm --filter @codesync/api dev	Start only the API server
pnpm --filter @codesync/collab dev	Start only the CRDT server

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Running Tests

Run the full test suite across all packages:

pnpm test

Run tests for a specific package:

pnpm --filter @codesync/api test      # API tests (auth, gateway, AI, recordings, persistence, LiveKit)
pnpm --filter @codesync/collab test    # CRDT collaboration tests

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Docker Compose

Launch the complete stack in containers:

docker compose up --build

Services:

Service	Port
Web Client	http://localhost:5173
NestJS API	http://localhost:3001
Hocuspocus Server	ws://localhost:1234
LiveKit SFU	ws://localhost:7880
PostgreSQL	localhost:5432
Redis	localhost:6379
MinIO	localhost:9000

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Contributing

All contributions must follow the rules defined in AGENTS.md:

1. Shared types first — Shared logic, DTOs, and schemas go in packages/shared-types or packages/ui. No duplicating concerns across apps.
2. Strict type contracts — Every socket event, payload, and API endpoint must be fully typed in shared-types before use.
3. No fallow dependencies — Every added dependency must be actively used.
4. Build & test gate — pnpm build and pnpm test must pass before any merge.
5. No in-browser code execution — Running user code is explicitly out of scope.

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License

This project is licensed under the GNU General Public License v3.0.