This repository implements BitTorrent-related packages and command-line utilities in Go. The emphasis is on use as a library from other projects. It's been used 24/7 in production by a downstream, private service since late 2014.

There is support for protocol encryption, DHT, PEX, uTP, and various extensions. See the package documentation for a more complete list. There are several data storage backends provided: blob, file, and mmap, and you can write your own, such as to store data on S3, or in a database. You can use the provided binaries in ./cmd, or use package torrent as a library for your own applications.

Many of the sub-packages can be used for other purposes: bencode, and tracker, in particular.

Install the library package with go get github.com/anacrolix/torrent, or the provided cmds with go get github.com/anacrolix/torrent/cmd/....

There is a small example in the package documentation.

• Go Peerflix
• Cloud Torrent
• Android Torrent Client
• Android libtorrent
• Trickl - Torrent Client
• Confluence

Here I'll describe what some of the provided commands in ./cmd do.

Note that the godo command which is invoked in the following examples builds and executes a Go import path, like go run. It's easier to use this convention than to spell out the install/invoke cycle for every single example.

Downloads torrents from the command-line. This first example does not use godo.

$ go get github.com/anacrolix/torrent/cmd/torrent
# Now 'torrent' should be in $GOPATH/bin, which should be in $PATH.
$ torrent 'magnet:?xt=urn:btih:KRWPCX3SJUM4IMM4YF5RPHL6ANPYTQPU'
ubuntu-14.04.2-desktop-amd64.iso [===================================================================>]  99% downloading (1.0 GB/1.0 GB)
2015/04/01 02:08:20 main.go:137: downloaded ALL the torrents
$ md5sum ubuntu-14.04.2-desktop-amd64.iso
1b305d585b1918f297164add46784116  ubuntu-14.04.2-desktop-amd64.iso
$ echo such amaze
wow

torrentfs mounts a FUSE filesystem at -mountDir. The contents are the torrents described by the torrent files and magnet links at -metainfoDir. Data for read requests is fetched only as required from the torrent network, and stored at -downloadDir.

$ mkdir mnt torrents
$ godo github.com/anacrolix/torrent/cmd/torrentfs -mountDir=mnt -metainfoDir=torrents &
$ cd torrents
$ wget http://releases.ubuntu.com/14.04.2/ubuntu-14.04.2-desktop-amd64.iso.torrent
$ cd ..
$ ls mnt
ubuntu-14.04.2-desktop-amd64.iso
$ pv mnt/ubuntu-14.04.2-desktop-amd64.iso | md5sum
996MB 0:04:40 [3.55MB/s] [========================================>] 100%
1b305d585b1918f297164add46784116  -

Creates a magnet link from a torrent file. Note the extracted trackers, display name, and info hash.

$ godo github.com/anacrolix/torrent/cmd/torrent-magnet < ubuntu-14.04.2-desktop-amd64.iso.torrent
magnet:?xt=urn:btih:546cf15f724d19c4319cc17b179d7e035f89c1f4&dn=ubuntu-14.04.2-desktop-amd64.iso&tr=http%3A%2F%2Ftorrent.ubuntu.com%3A6969%2Fannounce&tr=http%3A%2F%2Fipv6.torrent.ubuntu.com%3A6969%2Fannounce