Jannis Braun
44b6317c16
Three stacked bugs prevented federation relay from working for group DMs:
1. Origin format mismatch: users.home_instance stores bare domains
("nova.ddns.net") but federation_peers.origin stores full URLs
("https://nova.ddns.net"). getGroupDmTargetOrigins() built target
lists from bare domains, so queueOutboxEvent() never matched any
peers — events were never queued into the outbox.
2. Missing federatedId in outbox reconstruction: the outbox worker
rebuilt relay events from stored payloads but never copied the
federatedId field. Receiving instances check this field and rejected
all member_add/remove/ownership_transfer events with
"missing_membership_payload".
3. Duplicate channels from cross-instance broadcasts: dm_channel_created
was sent to ALL members including remote replicas. Users connected to
multiple instances received the event twice (once per instance),
creating duplicate group DMs in their sidebar. Fixed by only
broadcasting to members whose home instance matches the current
server — remote members receive the channel via federation bootstrap
on their home instance.
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