(def *assert-args* true) ; turn this false in production code

(defn foo
[^String x]
(if *assert-args* (assert (string? x)))
..)

;;; while calling foo in production
(binding [*assert-args* false]
(foo “hello”))

Would rather say that make this *assert-args* application-wide so that all functions in your app honour it. I am using this technique in SLRat:
http://bitbucket.org/kumarshantanu/sqlrat/src

A better idea may be to define assert-args like this:

(def *assert-args* (atom false))
(defn assert-args? [] (@*assert-args*))
(defn toggle-assert-args []
..) ; toggle the value, invoke from backdoor in production

brew install clojure, add clojure mode to emacs, la clojure to idea or counterclockwise to eclipse and you’re ready to roll. Add leningen to your project and dependencies are a done deal.