Nexus

Decentralized P2P chat and file-sharing desktop application.

Built with Electron + React + TypeScript on the frontend and Rust (libp2p) for peer-to-peer networking. A hub server handles signaling, room chat, and user discovery, while direct messages and file transfers go peer-to-peer.

Project Structure

nexus/
  apps/desktop/       Electron desktop app (React + TypeScript)
  packages/p2p-core/  Rust native addon (libp2p via napi-rs)
  infra/hub/          Hub server (Rust, Socket.IO + Axum)
  infra/bootstrap/    Bootstrap node for libp2p peer discovery

Prerequisites

• Node.js >= 20
• Rust >= 1.85 (install via rustup)
• npm (comes with Node.js)

Setup

From the root:

npm install

Building the Native Addon (p2p-core)

The desktop app depends on the Rust native addon. Build it before running the app:

cd packages/p2p-core
npm run build

This produces a .node binary and auto-generated index.js + index.d.ts.

Running in Development

1. Start the Hub Server

cargo run -p nexus-hub

Listens on port 4001 by default. Options:

--port <PORT>        Port to listen on (default: 4001)
--db-path <PATH>     SQLite database path (default: nexus-hub.db)
--data-dir <DIR>     Data directory for avatars (default: ./data)

2. Start the Bootstrap Node

cargo run -p nexus-bootstrap

Listens on port 4001 (TCP + QUIC/UDP) by default. Options:

--port <PORT>        Port to listen on (default: 4001)
--data-dir <DIR>     Directory for persistent identity key (default: ./data)

On first run it generates an ed25519 keypair and prints the PeerId. Update the dev bootstrap peers in apps/desktop/src/shared/config.ts if the PeerId changes.

3. Start the Desktop App

cd apps/desktop
npm run dev

In dev mode the app connects to 127.0.0.1:4001 (hub) and 127.0.0.1:4002 (bootstrap) automatically.

Production Configuration

Before building for production, update the server addresses in apps/desktop/src/shared/config.ts:

export const HUB_URL = import.meta.env.DEV
  ? 'http://127.0.0.1:4001'
  : 'https://your-server.com:4001'    // <-- your production hub URL

export const BOOTSTRAP_PEERS: string[] = import.meta.env.DEV
  ? [ /* local dev peers */ ]
  : [
      '/ip4/YOUR_SERVER_IP/tcp/4003/p2p/YOUR_PEER_ID',       // <-- production bootstrap
      '/ip4/YOUR_SERVER_IP/udp/4003/quic-v1/p2p/YOUR_PEER_ID',
    ]

Replace YOUR_SERVER_IP with the public IP of your server and YOUR_PEER_ID with the PeerId printed by the bootstrap node on first run.

Building for Production

Hub Server

cargo build -p nexus-hub --release

Binary: target/release/nexus-hub

Bootstrap Node

cargo build -p nexus-bootstrap --release

Binary: target/release/nexus-bootstrap

Desktop App

cd apps/desktop

npm run build:mac     # macOS (.dmg)
npm run build:win     # Windows (.exe)
npm run build:linux   # Linux (.AppImage, .deb, .snap)

Output goes to apps/desktop/dist/.

Running in Production

Example for a Linux server:

# Hub (port 4001)
./nexus-hub --port 4001 --db-path /var/lib/nexus/hub.db --data-dir /var/lib/nexus/data

# Bootstrap (port 4003)
./nexus-bootstrap --port 4003 --data-dir /var/lib/nexus/bootstrap