BitTorrent Support

FatRat downloads torrents with the BitTorrent engine, next to its HTTP and FTP downloads. A torrent is a transfer like any other: it lives in a queue, and you start, pause and remove it in the usual way. See Transfers and Queues.

The one big difference is that a torrent does not finish when its download finishes. FatRat keeps it active and seeds it (uploads to other people) until a limit is reached. See Seeding below.

Adding torrents

Add a torrent like any other transfer, in the New transfer dialog (desktop and web interface) or in the terminal client. FatRat accepts:

Magnet links, which start with magnet:?xt=urn:btih:. FatRat first downloads the torrent's metadata from other peers. Until then the transfer shows "Downloading metadata" instead of a name, and the list of files is not available.
Links to .torrent files (http or ftp). FatRat downloads the file, then starts the torrent. Some torrent sites hand out torrent files from links that do not end in .torrent. FatRat knows the link patterns of a few of them, from the file btlinks.txt in its data directory.
Local .torrent files. On the desktop, use Add special → Add local files... in the New transfer dialog. In the web interface, use Choose files… under Local files (e.g. .torrent). In the terminal client, enter the path of the file in Links; it is uploaded to FatRat.

You can also drop .torrent and .magnet files into a queue's watch folder, or let RSS add them.

If you leave Download as (or Auto detect) alone, FatRat picks the BitTorrent engine for these links. If an ordinary HTTP or FTP download turns out to be a torrent file, FatRat can convert it into a torrent transfer. This is switched on with Convert the transfer to BitTorrent if the downloaded file is found to be a torrent on the HTTP/FTP settings page (on by default).

FatRat keeps a copy of each .torrent file in .local/share/fatrat/torrents in the home directory of the user it runs as.

Choosing files and priorities

A torrent often holds many files. You can skip some and download others sooner.

Desktop: select the torrent and open the Files tab in the details panel. Right-click a file and choose Priority, then Do not download, Normal, Increased or Maximum. Open opens the file. The Details panel also has the tabs General (the tracker, whether the torrent is private, the share ratio, the piece length, the creator, the comment and the magnet link), Peers and Pieces.

Another way: open the transfer's properties (Transfer → Properties...). Its Details page has Files to download, a tree of the files with a check box on each file and folder. Clear the box of a file to skip it.

Web interface: select the torrent and open Details. The files are in a table with the columns File Name, File Size, Progress and Priority. The priority is Do not download, Normal, Increased or Maximum.

Terminal: open the transfer (Enter) and go to the Files tab. + and - change the priority of a file, S skips it, A downloads all files, and Enter applies the changes. See Terminal Interface.

Seeding

An active torrent has two phases: downloading and seeding. When all the files you asked for are downloaded, FatRat logs "The torrent has been downloaded" and the transfer counts as an upload from then on (this matters for the upload speed limit and the number of running uploads of its queue). FatRat marks the transfer Completed when one of these limits is reached:

the share ratio is reached: the amount uploaded divided by the amount downloaded;
or the transfer has uploaded a given number of megabytes.

A torrent that you force start (Force start on the desktop, Force Resume in the web interface, Force resume in the terminal client) is never completed because of these limits. Use this to seed a torrent indefinitely.

The ratio for new torrents is set in the BitTorrent settings (see below). It is 1 at first. You can set different limits for one torrent in its properties:

Desktop: Transfer → Properties..., page Details, Seeding limits. Tick Seed up to ratio and enter the ratio; tick Seed until specified amount of data has been uploaded and enter the amount in MB. If you leave Seed up to ratio unticked, or enter 0, the torrent completes as soon as it is downloaded (the tooltip of the check box says so). Because of that, the amount limit only has an effect when Seed up to ratio is ticked and above 0. An amount of 0 means no amount limit.
Web interface: Properties, Options: Seed up to ratio (0 = stop when downloaded) and Seed until uploaded (0 = no limit), in MB.
Terminal: the transfer properties (E) show the same fields under Options.

Use super seeding is in the same place. Super seeding is a mode for the first seeder of a torrent: FatRat offers each piece to one peer at a time, which spreads the pieces more efficiently when nobody else has the full torrent yet.

On the desktop, the properties of a torrent also let you edit the URL seeds (web addresses that serve the same files, starting with http://) and the Trackers (addresses starting with http:// or udp://) of the torrent.

Settings

Desktop: Settings → Settings..., page BitTorrent. Web interface: the BitTorrent page of the settings dialog. Terminal: press O (or F2) and pick the BitTorrent page. The web interface and the terminal client show most, but not all, of the settings below; the ones they lack are marked.

Main

Listen port start, Listen port end: (Web interface and terminal: Listen port (from) and Listen port (to).) FatRat listens for connections from other peers, on IPv4 and IPv6, on the first free port from the start to the end of this range. The defaults are 6881 and 6888. If you are behind a firewall or router, open or forward the ports of the range (or use UPnP or NAT-PMP, below).
External IP: The address that FatRat announces to trackers as its own. Enter a literal IP address, such as 203.0.113.7; a host name does not work. If it is empty or is not an IP address, the BitTorrent library decides. Leave it empty unless you know you need it.
Seed up to ratio (default value): The ratio that new torrents start with. Default 1.
Maximum connections (global/per torrent): How many peers FatRat connects to, in total and for each torrent. Default 200 and 200.
Maximum uploads (global/per torrent): How many peers FatRat uploads to at the same time, in total and for each torrent. Default 5 and 5.
Maximum open files: How many files FatRat keeps open at once. Default 100.
File allocation mode: Full, Sparse or Compact. Default Full.
Proxy: Desktop only. None, or one of the proxy servers you have defined in the settings. FatRat connects to peers through it.
Identify as: Desktop only. How FatRat names itself to other peers: FatRat, μTorrent or Azureus/Vuze. Some private trackers only allow certain clients.
Enable distributed tracker (DHT): Finds peers without a tracker. On by default. Torrents marked private never use DHT.
Enable uTorrent Peer Exchange: Lets peers tell each other about more peers. On by default. A change takes effect after FatRat is restarted.
Enable Local Service Discovery: Finds peers on your local network.
Clean up the .torrent storage: Desktop only. Deletes the stored copies of .torrent files whose torrents are no longer in FatRat, and reports how many it removed.

Encryption

Encryption of incoming connections, Encryption of outgoing connections: Disabled, Enabled or Permit only encrypted. The default is Enabled for both.
Encryption levels: Plaintext, RC4 or Both. Default Both.
Prefer RC4: Off by default.

Port mapping

Enable UPnP, Enable NAT-PMP: Ask your router to forward the listen port to this computer automatically.

Torrent search

Desktop only: Open pages with details is in a new tab or in an external browser.

Creating torrents

The desktop can make a .torrent file from your own files. See Creating Torrents.