Does not need Steam client running, or even a GUI. Fully based on SteamKit2 and reverse-engineered Steam protocol.
Automatically farm steam cards using any number of active accounts
Automatically accept friend requests sent from master
Automatically accept all trades coming from master
Automatically accept all steam cd-keys sent via chat from master
SteamGuard / 2-factor-authentication support
Full Mono support, tested on Debian "9.0" Stretch (testing)

TODO:

Smart multi-games farming till every game reaches 2 hours, then one-by-one (similar to Idle Master) - Backend code is already here, just missing the logic and tests.
Possible integration with SteamTradeMatcher, bot can detect dupes and trade them automatically. Again, backend code is already here, just missing actual implementation.
Automatic sending of steam trades to master, after game is fully farmed.
Probably much more

This is big WIP, so feel free to send pull requests if you wish.

I'll release some releases later, when everything is tested and code cleaned up.