Oops, this is wrong: (repl/repl "http://localhost:9000 http://localhost:9000 ") Should be (repl/connect "http://localhost:9000/repl http://localhost:9000/repl "

Oops, this is wrong: (repl/repl "http://localhost:9000 http://localhost:9000 ") Should be (repl/connect "http://localhost:9000/repl http://localhost:9000/repl ") I also kind of misread MatthewPhillips post and thought he was looking for Emacs instructions. For sending code to the browser from a normal REPL, (started with `lein repl`) I think a good place to start is these two files from Cljs One: https://github.com/brentonashworth/one/blob/master/src/app/clj/one/sample/repl.clj https://github.com/brentonashworth/one/blob/master/src/app/c... https://github.com/brentonashworth/one/blob/master/src/lib/clj/one/tools.clj https://github.com/brentonashworth/one/blob/master/src/lib/c... Together they should help in setting this up for a vanilla Cljs project, or require them in your fork of Cljs One and start a REPL.