Jannis Braun
b698ded47d
Two correctness/defense fixes plus regression tests in the existing in-memory drizzle test file. 1. Reverse-direction idempotency. The sender-side path in social.ts checks BOTH directions of friend_requests and returns 409 incoming_request_exists when an opposite-direction row exists. The receiver only matched from->to, so cross-fire (alice@A and bob@B both click "add friend" near-simultaneously) produced two opposite pending rows on each instance. The receiver now silent-accepts when either direction matches a pending row, mirroring the sender's both-direction check. 2. Self-target guard (defense-in-depth). Reject events whose from-identity equals to-identity (after normalizeOriginForCompare) with a new receiver-acknowledged 4xx code self_target_invalid. Sender's local cannot_friend_self should catch this, but the receiver does not trust upstream validation. Added to TERMINAL_REJECTION_REASONS so the standard rollback fires (mapped client-side to peer_rejected). Logged at console.warn. Spec updates: social.md inbound contract now documents both-direction idempotency and the self-target guard; federation.md and the s2s-friend-add design spec list the new terminal rejection reason.
Backspace
Open-source, self-hosted Discord alternative built with TypeScript.
Features
- Real-time text messaging with WebSocket
- Servers, channels, and role-based permission management
- Voice and video chat via LiveKit
- Screen sharing with configurable quality (VP9)
- Direct messages (1-on-1 and group DMs up to 10)
- DM voice/video calls with ringing
- Friend system with requests
- File uploads and image sharing
- Markdown message formatting with syntax highlighting
- Message reactions, replies, and editing
- Typing indicators, presence status, and read states
- Invite system with shareable codes
- Instance-level admin panel (streaming limits)
- Desktop app (Electron)
- Mobile-responsive web UI
- Docker deployment
Tech Stack
| Layer | Technology |
|---|---|
| Backend | Fastify + TypeScript |
| Database | SQLite (better-sqlite3) + Drizzle ORM |
| Auth | JWT + bcrypt |
| Real-time | WebSocket (ws) |
| Frontend | React 18 + Tailwind CSS + Zustand |
| Voice/Video | LiveKit |
| Desktop | Electron |
| Build | Vite + pnpm workspaces |
Quick Start with Docker
# Clone the repository
git clone https://github.com/your-username/backspace.git
cd backspace
# Create environment file
cp .env.example .env
# Generate a JWT secret
echo "JWT_SECRET=$(openssl rand -hex 32)" >> .env
# Start Backspace
docker compose up -d
Open http://localhost:3000 in your browser. A default server "Backspace" is created automatically.
Default admin account: admin / admin123 (change this after first login).
Development Setup
Prerequisites
- Node.js 20+
- pnpm 8+
Install
pnpm install
Configure
cp .env.example .env
# Edit .env with your settings (generate a JWT_SECRET)
Run
# Start both server and web dev server
pnpm dev
# Or start individually
pnpm dev:server # API server on :3005
pnpm dev:web # Vite dev server on :5173
Build
pnpm build
This builds the shared types, server, and web frontend. The server serves the built frontend in production mode.
Project Structure
Backspace/
├── packages/
│ ├── shared/ # Shared TypeScript types & permissions
│ ├── server/ # Fastify API + WebSocket server
│ ├── web/ # React frontend (Vite + Tailwind)
│ └── desktop/ # Electron desktop app
├── data/ # SQLite DB + uploads (created at runtime)
├── Dockerfile
├── docker-compose.yml
└── .env.example
Voice & Video
Voice and video requires a LiveKit server. Set these in your .env:
LIVEKIT_URL=wss://your-livekit-server
LIVEKIT_API_KEY=your-api-key
LIVEKIT_API_SECRET=your-api-secret
Without LiveKit configured, text chat works fully but voice/video channels will not connect.
API
The server exposes a REST API and WebSocket endpoint:
- REST API:
http://localhost:3000/api/* - WebSocket:
ws://localhost:3000/ws - Health check:
GET /api/health
See CLAUDE.md for the full API reference.
Desktop App
The Electron desktop app wraps the web UI and adds system tray, notifications, and native window controls.
cd packages/desktop
pnpm build:ts # Compile TypeScript
pnpm dev # Run in development
pnpm build # Package for distribution
License
MIT