Worked on ?extensible addurl today. When git annex addurl is run, remotes will be asked if they claim the url, and whichever remote does will be used to download it, and location tracking will indicate that remote contains the object. This is a masive 1000 line patch touching 30 files, including follow-on changes in rmurl and whereis and even rekey.

It should now be possible to build an external special remote that handles *.torrent and magnet: urls and passes them off to a bittorrent client for download, for example.

Another use for this would be to make an external special remote that uses youtube-dl or some other program than quvi for downloading web videos. The builtin quvi support could probably be moved out of the web special remote, to a separate remote. I haven't tried to do that yet.