🛰️ LocalBeam

LocalBeam is a lightweight, zero-config peer-to-peer communication library built on top of WebRTC, enabling real-time data, file, and message transfer between devices on the same local network — without any external servers.

It combines a local signaling server (using WebSockets + Bonjour/mDNS discovery) with a simple client SDK that works seamlessly in React, Node, or browser environments.

⚡ Key Features

• 🧭 Automatic peer discovery via Bonjour (mDNS)
• 🔗 Peer-to-peer connections using WebRTC
• 💬 Real-time messaging and binary data transfer
• 📦 File sharing support (with metadata & auto-downloads)
• 🧱 Pluggable transfer strategies (direct, chunked, etc.)
• 🪶 Lightweight — built for LAN & local-first apps
• 🧩 Framework-agnostic (works with any JS framework)

🧰 Installation

npm install localbeam
# or
yarn add localbeam

If running locally for development:

git clone https://github.com/<your-username>/localbeam.git
cd localbeam
npm install

🧠 Quick Start

1️⃣ Start the LocalBeam signaling server

node server.js

You should see logs like:

[INFO] LocalBeam server running on port 3001
[INFO] Bonjour service published: LocalBeam Signaling Server

2️⃣ Use the LocalBeam client SDK in your app

Example (React):

import React, { useEffect, useState } from "react";
import { PeerManager, SignalingClient } from "localbeam";

export default function App() {
  const [clientId] = useState("client-" + Math.floor(Math.random() * 1000));
  const [manager, setManager] = useState(null);
  const [peers, setPeers] = useState([]);
  const [messages, setMessages] = useState([]);
  const [input, setInput] = useState("");

  useEffect(() => {
    const signaling = new SignalingClient(clientId, { baseUrl: "http://localhost:3001" });
    const peerManager = new PeerManager(signaling, clientId);
    setManager(peerManager);

    signaling.connect();
    peerManager.on("peer-list", (list) => setPeers(list.filter(p => p !== clientId)));
    peerManager.on("peer-connected", (pid) => setMessages(m => [...m, `✅ Connected to ${pid}`]));
    peerManager.on("data", (_from, data) => setMessages(m => [...m, `📩 ${data}`]));

    return () => peerManager.closeAll();
  }, [clientId]);

  const send = () => {
    if (!manager) return;
    peers.forEach(p => manager.send(p, input));
    setMessages(m => [...m, `📤 ${input}`]);
    setInput("");
  };

  return (
    <div>
      <h3>LocalBeam Demo</h3>
      <p>Client ID: {clientId}</p>
      <p>Peers: {peers.join(", ") || "none"}</p>
      <input value={input} onChange={e => setInput(e.target.value)} />
      <button onClick={send}>Send</button>
      <pre>{messages.join("\n")}</pre>
    </div>
  );
}

✅ Open the app in two browsers or devices on the same LAN — they'll auto-discover and connect.

📤 Sending Files

const sendFile = async (e) => {
  const file = e.target.files?.[0];
  if (!file || !manager) return;

  const arrayBuffer = await file.arrayBuffer();
  const payload = {
    type: "file",
    name: file.name,
    mime: file.type,
    size: file.size,
    data: Array.from(new Uint8Array(arrayBuffer)),
  };

  peers.forEach(p => manager.send(p, payload));
};

Receiving peers will automatically reconstruct and download the file.

🧩 Architecture

LocalBeam
├── server/                # Signaling + discovery (WebSocket + Bonjour)
│   └── server.js
├── src/core/
│   ├── signalingClient.ts # WebSocket signaling logic
│   ├── peerManager.ts     # WebRTC peer lifecycle management
│   └── strategies/
│       ├── directTransfer.ts   # Simple direct send
│       ├── chunkedTransfer.ts  # (optional) large files
│       └── ...
└── examples/react-demo/   # Example React app

📦 Example Implementations

| Project | Type | Status | Repo | |--------|------|:------:|------| | localbeam-react | React example app demonstrating peer discovery & file transfer | ✅ Done | localbeam-react |

⚙️ Configuration

| Option | Default | Description | |--------|---------|-------------| | baseUrl | http://localhost:3001 | Signaling server URL | | bonjourService | LocalBeam Signaling Server | Bonjour (mDNS) name | | port | 3001 | WebSocket server port |

📚 API Reference

SignalingClient

| Method | Description | |--------|-------------| | connect() | Connect to signaling server | | on(event, handler) | Listen to "open", "close", "peer-list" |

PeerManager

| Method | Description | |--------|-------------| | createConnection(peerId) | Initiate WebRTC connection | | send(peerId, data) | Send text, buffer, or file | | closeAll() | Close all active connections | | on(event, handler) | Listen to "peer-connected", "data", "peer-list" |

🧪 Example Logs

[INFO] WebSocket connected to ws://192.168.1.21:3001
[INFO] Peer registered: react-client-217
[INFO] ✅ Connected to peer react-client-634
[INFO] 📦 Received file: sample.pdf (128KB)

💡 Use Cases

• LAN chat or collaboration tools
• Classroom / office file sharing
• IoT or local device communication
• Offline-first syncing
• Local multiplayer games

🗺️ Roadmap

Here's what's coming next in LocalBeam:

📱 Reference Applications

• React File Transfer App: A polished, production-ready example showcasing real-time file sharing and chat
• Electron Desktop Client: Cross-platform desktop application demonstrating native integration capabilities
• Both applications will serve as comprehensive implementation guides for the community

🌍 Global Connectivity

• Cloud Signaling Infrastructure: Optional hosted signaling service for beyond-LAN connections
• Secure Remote Discovery: Encrypted peer discovery without mDNS dependency
• Authentication & Authorization: Built-in support for secure peer verification
• NAT Traversal: Improved STUN/TURN support for reliable connections across networks

⚡ Performance Enhancements

• Streaming Transfer Strategy: Efficient handling of large files (100MB+)
• Chunked File Protocol: Resume support and progress tracking
• Compression Options: Smart compression based on file types
• Multi-Connection Transfer: Parallel chunk transfer for faster speeds

🎯 Future Features

• Enhanced encryption and security features
• Connection quality metrics and diagnostics
• Plugin system for custom transfer strategies
• Mobile platform support (React Native)
• And more coming soon...

Follow the GitHub repository for updates!

🤝 Contributing

Contributions are welcome! To start hacking:

git clone https://github.com/<your-username>/localbeam.git
cd localbeam
npm install
npm run dev

Submit PRs or open issues for bugs, features, or documentation.

📜 License

MIT License © 2025 Oneiros8 Use freely, modify, and share.

🌟 Acknowledgments

• simple-peer
• bonjour
• ws