PeerJS Server

by peers


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PeerServer: A server for PeerJS

PeerServer helps broker connections between PeerJS clients. Data is not proxied through the server.

Run your own server on Gitpod!

Open in Gitpod

Run PeerServer

  1. Install PeerServer from npm or github:


npm install peer


git clone
npm install
  1. Run the server:
$> peerjs --port 9000 --key peerjs --path /myapp

Or, create a custom server:

const { PeerServer } = require('peer');
const server = PeerServer({port: 9000, path: '/myapp'});
  1. Check that server works: open browser with http://localhost:9000/myapp It should returns JSON with name, description and website fields.

Connecting to the server from PeerJS:

    const peer = new Peer('someid', {host: 'localhost', port: 9000, path: '/myapp'});

Using HTTPS: Simply pass in PEM-encoded certificate and key.

const fs = require('fs');
const { PeerServer } = require('peer');

const server = PeerServer({
  port: 9000,
  ssl: {
    key: fs.readFileSync('/path/to/your/ssl/key/here.key'),
    cert: fs.readFileSync('/path/to/your/ssl/certificate/here.crt')

Running PeerServer behind a reverse proxy

Make sure to set the proxied option, otherwise IP based limiting will fail. The option is passed verbatim to the expressjs trust proxy setting if it is truthy.

const { PeerServer } = require('peer');
const server = PeerServer({port: 9000, path: '/myapp', proxied: true});

Combining with existing express app

const express = require('express');
const app = express();
const { ExpressPeerServer } = require('peer');

app.get('/', (req, res, next) => { res.send('Hello world!'); });

// =======

const server = app.listen(9000);

const options = {
    debug: true

const peerserver = ExpressPeerServer(server, options);

app.use('/api', peerserver);

// == OR ==

const server = require('http').createServer(app);
const peerserver = ExpressPeerServer(server, options);

app.use('/peerjs', peerserver);


// ========


The 'connection' event is emitted when a peer connects to the server.

peerserver.on('connection', (client) => { ... });

The 'disconnect' event is emitted when a peer disconnects from the server or when the peer can no longer be reached.

peerserver.on('disconnect', (client) => { ... });

Running tests

npm test


You can build this image simply by calling:

docker build -t peerjs

To run the image execute this:

docker run -p 9000:9000 -d peerjs

This will start a peerjs server on port 9000 exposed on port 9000.


Discuss PeerJS on our Telegram chat:

Please post any bugs as a Github issue.