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Read, make, and hash check torrents with node.js!

Build Status Dependency Status codecov


Read a torrent

var nt = require('nt');'path/to/file.torrent', function(err, torrent) {
  if (err) throw err;
  console.log('Info hash:', torrent.infoHash());
// If url is given, it will be downloaded.'', function(err, torrent) {
  if (err) throw err;

Make a torrent

var rs = nt.make('', __dirname + '/files');
// callback style 
nt.makeWrite('outputfile', '', __dirname + '/files',
  ['somefile.ext', '', 'inside/afolder.mkv', 'afolder'],
  function(err, torrent) {
    if (err) throw err;
    console.log('Finished writing torrent!');

Hash check a torrent

var hasher = torrent.hashCheck(file);
var p;
hasher.on('match', function(i, hash, percent) {
  p = percent;
hasher.on('end', function() {
  console.log('Hash Check:', p + '%', 'matched');


read(file, [requestOptions], callback(Error, Torrent))

Reads a local file, remote file, or a readable stream. If file is a URL, it will be downloaded. requestOptions is optional, and can be used to customize the http request made by request. Returns readable stream.

An error can be returned if the torrent is formatted incorrectly. Does not check if the dictonaries are listed alphabetically. Refer to the BitTorrent Specification for more info on torrent metainfo.

make(announceURL, dir, [files], [options], [callback(Error, Torrent)])

Makes a new torrent. dir is root directory of the torrent. The files array will relatively read files from there. If files is omitted, it implicitly adds all of the files in dir to the torrent, including those in subdirectories. options can have the following:

  • announceList - An array of arrays of additional announce URLs.
  • comment
  • name - Can be used only in multi file mode. If not given, defaults to name of directory.
  • pieceLength - How to break up the pieces. Must be an integer n that says piece length will be 2^n. Default is 256KB, or 2^18.
  • private - Set true if this is a private torrent.
  • moreInfo - These go into the info dictionary of the torrent. Useful if you want to make a torrent have a unique info hash from a certain tracker.
  • maxFiles - Max files to open during piece hashing. Defaults to 250.

callback is called with a possible Error, and a Torrent object when hashing is finished.

make returns a Hasher object that emits raw bencoded data events.

makeWrite(output, annlounce, dir, [files], [options], [callback(Error, Torrent)])

A shortcut that pumps the returned readable stream from make into a writable stream that points to the file output. Returns a Hasher object.


The read and make functions all call their callback with a Torrent object.


Contains metadata of the torrent. Example:

  announce: 'udp://',
  'announce-list': [
    [ 'udp://' ],
    [ 'udp://' ],
    [ 'udp://' ],
    [ '' ]
  comment: 'Torrent downloaded from',
  'creation date': 1303979726,
  info: { length: 718583808,
    name: 'ubuntu-11.04-desktop-i386.iso',
    'piece length': 524288,
    pieces: <Buffer e5 7a ...>


Get a torrent's info hash.


Creates a ReadableStream that emits raw bencoded data for this torrent. Returns the readable stream.


Shortcut that pipes the stream from Torrent#createReadStream() to a writable file stream. Returns the writable stream.

Torrent#hashCheck(dir, [options])

Hash checks torrent against files in dir. Returns a Hasher object. options hash can have maxFiles to open during hashing. Defaults to 250. Returns a Hasher object.


A Hasher object is returned when a torrent is created with make and when Torrent#hashCheck is called. It inherits from ReadableStream.


Pause hash checking.


Resumes hash checking.


Continues hashing if paused or pauses if not.


Stops hashing completely. Closes file descriptors and does not emit any more events.


  • 'ready' function () { }

Finished examining files to be hashed and ready to start hashing their contents.

  • 'data', function (data) { }

Emits raw bencoded torrent data only when hasher is returned from the make function.

  • 'progress' function (percent, speed, avgSpeed) { }

Emits the progress calculated by amount of bytes read from files. speed and avgSpeed are in bytes.

  • 'hash' function (index, hash, file, position, length) { }

Emitted when a piece is hashed along with hash position and source.

  • 'match' function (index, hash, percentMatched, file, position, length) { }

Emitted when a piece matches with its index, the piece, and the percentage of pieces matched so far.

  • 'matcherror' function (index, file, position, length) { }

Emitted when a piece does not match.

  • 'error' function (err) { }

Error hash checking.

  • 'end' function () { }

Hash checking is finished.


npm install nt


Tests are written with vows

npm test