Similar to the [[web]] special remote, git-annex can use BitTorrent as
a source for files that are added to the git-annex repository.

It supports both `.torrent` files, and `magnet:` links. When you run `git
annex addurl` with either of these, it will download the contents of the
torrent and add it to the git annex repository.

See [[tips/using_the_web_as_a_special_remote]] for usage examples.

git-annex uses [aria2](http://aria2.sourceforge.net/) to download torrents.

If git-annex is not built using the haskell torrent library to parse
torrents, it also needs the needs the `btshowmetainfo` program, from
either bittornado or the original BitTorrent client.

## notes

Currently git-annex only supports downloading content from a torrent; 
it cannot upload or remove content.

Multi-file torrents are supported; to handle them, `git annex addurl`
will add a directory containing all the files from the torrent.

It's hard to say if a torrent is healthy enough to let a file be downloaded
from it, and harder to predict if a torrent will stay healthy. So,
git-annex takes a cautious approach and when dropping a file, won't
treat this special remote as one of the required [[copies]]. It's probably
a good idea to configure git-annex to fully distrust this remote, by
running `git annex untrust bittorrent`

This feature is available only from version `5.20141219`.
