Source executed via Replete REPL can depend on other bootstrapped-compatible libraries. To do so, the library must be bundled in Replete. (There is no facility to download dependencies into Replete.)
Replete ships with many of the deps that are available to conventional ClojureScript code. In particular this includes most of the Google Closure library as well as these namespaces:
cljs.testclojure.core.reducersclojure.dataclojure.templateclojure.stringclojure.setclojure.walkclojure.zipIn addition, Replete REPL ships with these libraries: