is it detectable by warden?

Simply put no.
It doesn't use any injected dll's however if battle.net monitored your play and noticed you followed a group of pixels and used the exact same locations every run i'm sure they could see it.

Although there are people who can elaborate on this and tell you more, I have not heard of anyone yet being banned. Plus the maker himself says he will never garentee 100% undetectable

as stated in the previous post it doesnt inject dlls making it very differcult for warden to detect, also if you use process guard it blocks warden from scanning certain things which helps protect you more

Although, to be perfectly honest. If blizzard did give a damn about hacks they'd pay attention to the mod mmbot makes to your d2 window :) it's just a show to get anti-hackers to think blizzard supports them :) lol