:browser-repl

Preload code necessary for connecting to the natively supported browser REPL. Defaults to false.

:browser-repl true

When true, adds clojure.browser.repl/preload to :preloads.

The natively supported browser REPL must be started from a custom script in Clojure. Start the REPL by calling cljs.repl/repl with the result of cljs.repl.browser/repl-env:

;; ClojureScript compiler script (in Clojure)

(require 'cljs.repl)
(require 'cljs.repl.browser)

(cljs.repl/repl (cljs.repl.browser/repl-env)
  :watch "src"
  :output-dir "out")