I say tools, because while a library would be cool, I'd understand if it was a binary/application to provide the functionality/user-experience that key base is aiming for.
I know this likely doesn't sound like something key base should be aiming for, but to me, programmers need encryption just as much as users. I'd like to write my libraries/programs with encryption, but I also want to be able to trust it and not fear some inherent vulnerability I'm adding.
To me, Keybase is aiming to solve/reduce these complexities for users, and I'm hoping they also aim to solve it for developers to.
Thanks for all the hard work folks @ Keybase, it's definitely appreciated!