This little module (and attendant command line tool and rackup app) exists for the purpose of providing rudimentary access control to a website when the prospective users are both small in number, and very busy. It circumvents schmucking around provisioning passwords by generating a link which you can pass to each of your users through some other mechanism, that when visited logs them in and keeps them logged in as long as you want. This is basically the equivalent of having a "forgot password" link without anybody having to click on "forgot password", and is perfectly adequate security in certain contexts, namely the ones the author of this gem is interested in.