Any way to watch for updates, or to write my own plugin?

[Trent]

I'm trying to get (or make) a P2P tool that will automatically get updates from a specific user or changes to a file/folder. I don't see any feature like that in BitTorrent. Please correct me if I'm wrong. Is there any facility to watch for new content?

Is there any plugin system for BitTorrent where I could write something like that?

I've seen how some tools follow an RSS feed. Does BitTorrent have that?

Thanks.