Awesome Open Source
Awesome Open Source

bittorrent-tracker ci npm downloads javascript style guide

Simple, robust, BitTorrent tracker (client & server) implementation

tracker visualization

Node.js implementation of a BitTorrent tracker, client and server.

A BitTorrent tracker is a web service which responds to requests from BitTorrent clients. The requests include metrics from clients that help the tracker keep overall statistics about the torrent. The response includes a peer list that helps the client participate in the torrent swarm.

This module is used by WebTorrent.


  • Includes client & server implementations
  • Supports all mainstream tracker types:
  • Supports ipv4 & ipv6
  • Supports tracker "scrape" extension
  • Robust and well-tested
  • Tracker statistics available via web interface at /stats or JSON data at /stats.json

Also see bittorrent-dht.

Tracker stats



npm install bittorrent-tracker



To connect to a tracker, just do this:

var Client = require('bittorrent-tracker')

var requiredOpts = {
  infoHash: new Buffer('012345678901234567890'), // hex string or Buffer
  peerId: new Buffer('01234567890123456789'), // hex string or Buffer
  announce: [], // list of tracker server urls
  port: 6881 // torrent client port, (in browser, optional)

var optionalOpts = {
  getAnnounceOpts: function () {
    // Provide a callback that will be called whenever announce() is called
    // internally (on timer), or by the user
    return {
      uploaded: 0,
      downloaded: 0,
      left: 0,
      customParam: 'blah' // custom parameters supported
  // RTCPeerConnection config object (only used in browser)
  rtcConfig: {},
  // User-Agent header for http requests
  userAgent: '',
  // Custom webrtc impl, useful in node to specify [wrtc](
  wrtc: {},

var client = new Client(requiredOpts)

client.on('error', function (err) {
  // fatal client error!

client.on('warning', function (err) {
  // a tracker was unavailable or sent bad data to the client. you can probably ignore it

// start getting peers from the tracker

client.on('update', function (data) {
  console.log('got an announce response from tracker: ' + data.announce)
  console.log('number of seeders in the swarm: ' + data.complete)
  console.log('number of leechers in the swarm: ' + data.incomplete)

client.once('peer', function (addr) {
  console.log('found a peer: ' + addr) //

// announce that download has completed (and you are now a seeder)

// force a tracker announce. will trigger more 'update' events and maybe more 'peer' events

// provide parameters to the tracker
  uploaded: 0,
  downloaded: 0,
  left: 0,
  customParam: 'blah' // custom parameters supported

// stop getting peers from the tracker, gracefully leave the swarm

// ungracefully leave the swarm (without sending final 'stop' message)

// scrape

client.on('scrape', function (data) {
  console.log('got a scrape response from tracker: ' + data.announce)
  console.log('number of seeders in the swarm: ' + data.complete)
  console.log('number of leechers in the swarm: ' + data.incomplete)
  console.log('number of total downloads of this torrent: ' + data.downloaded)


To start a BitTorrent tracker server to track swarms of peers:

var Server = require('bittorrent-tracker').Server

var server = new Server({
  udp: true, // enable udp server? [default=true]
  http: true, // enable http server? [default=true]
  ws: true, // enable websocket server? [default=true]
  stats: true, // enable web-based statistics? [default=true]
  filter: function (infoHash, params, cb) {
    // Blacklist/whitelist function for allowing/disallowing torrents. If this option is
    // omitted, all torrents are allowed. It is possible to interface with a database or
    // external system before deciding to allow/deny, because this function is async.

    // It is possible to block by peer id (whitelisting torrent clients) or by secret
    // key (private trackers). Full access to the original HTTP/UDP request parameters
    // are available in `params`.

    // This example only allows one torrent.

    var allowed = (infoHash === 'aaa67059ed6bd08362da625b3ae77f6f4a075aaa')
    if (allowed) {
      // If the callback is passed `null`, the torrent will be allowed.
    } else {
      // If the callback is passed an `Error` object, the torrent will be disallowed
      // and the error's `message` property will be given as the reason.
      cb(new Error('disallowed torrent'))

// Internal http, udp, and websocket servers exposed as public properties.

server.on('error', function (err) {
  // fatal server error!

server.on('warning', function (err) {
  // client sent bad data. probably not a problem, just a buggy client.

server.on('listening', function () {
  // fired when all requested servers are listening
  console.log('listening on http port:' + server.http.address().port)
  console.log('listening on udp port:' + server.udp.address().port)

// start tracker server listening! Use 0 to listen on a random free port.
server.listen(port, hostname, onlistening)

// listen for individual tracker messages from peers:

server.on('start', function (addr) {
  console.log('got start message from ' + addr)

server.on('complete', function (addr) {})
server.on('update', function (addr) {})
server.on('stop', function (addr) {})

// get info hashes for all torrents in the tracker server

// get the number of seeders for a particular torrent

// get the number of leechers for a particular torrent

// get the peers who are in a particular torrent swarm

The http server will handle requests for the following paths: /announce, /scrape. Requests for other paths will not be handled.

multi scrape

Scraping multiple torrent info is possible with a static Client.scrape method:

var Client = require('bittorrent-tracker')
Client.scrape({ announce: announceUrl, infoHash: [ infoHash1, infoHash2 ]}, function (err, results) {

  // ...

command line

Install bittorrent-tracker globally:

$ npm install -g bittorrent-tracker

Easily start a tracker server:

$ bittorrent-tracker
http server listening on 8000
udp server listening on 8000
ws server listening on 8000

Lots of options:

$ bittorrent-tracker --help
  bittorrent-tracker - Start a bittorrent tracker server

    bittorrent-tracker [OPTIONS]

  If no --http, --udp, or --ws option is supplied, all tracker types will be started.

    -p, --port [number]  change the port [default: 8000]
        --trust-proxy    trust 'x-forwarded-for' header from reverse proxy
        --interval       client announce interval (ms) [default: 600000]
        --http           enable http server
        --udp            enable udp server
        --ws             enable websocket server
    -q, --quiet          only show error output
    -s, --silent         show no output
    -v, --version        print the current version


MIT. Copyright (c) Feross Aboukhadijeh and WebTorrent, LLC.

Get A Weekly Email With Trending Projects For These Topics
No Spam. Unsubscribe easily at any time.
javascript (68,104
nodejs (3,638
server (510
browser (434
client (382
webrtc (327
torrent (142
bittorrent (97
tracker (83
webtorrent (43

Find Open Source By Browsing 7,000 Topics Across 59 Categories