A sample Austin ClojureScript REPL setup
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Using the Austin REPL to connect to your app

This is a minimal-ish example of getting an Austin ClojureScript REPL connected to your live app. It's extracted from yesterday's talk at Oslo Socially Functional meetup.


  • Compile ClojureScript: lein cljsbuild auto
  • Run the REPL: lein repl
  • From inside the REPL, run the server: (run!)
  • From inside the REPL, enter the ClojureScript REPL: (cljs!)
  • To quit the ClojureScript REPL, type :cljs/quit
  • Reap the benefits of your hard word: (js/alert "Hee haw!")


In my talk I ran the REPL inside Emacs with Cider. A command-line REPL is nice, but running the REPL inside your editor gives you crazy awesome abilities to evaluate single lines of code, loading code and switching namespace with simple key-bindings and more.

To try it out, install Cider (assuming a fairly recent Emacs):

M-x package-install [RET] cider [RET]

Then start cider (assuming your lein repl process is still running):

M-x cider RET RET 54478 RET

Replace the port number with the one reported by the lein repl process.

Alternatively, to start a separate REPL process from within emacs:

M-x cider-jack-in ;; C-c M-j
M-x cider-switch-to-repl-buffer ;; C-c C-z

Now, to load the contents of a Clojure(Script) file into the REPL process:

M-x cider-load-current-buffer ;; C-c C-k

To evaluate the namespace form:

M-x cider-repl-set-ns C-c M-n