# Shell

There are situations where having a REPL or shell can be useful. ES4X provides such a feature out of the box by running the command:

$ npm run "js:>"

js:>

And you are now able to REPL. For example:

js:> require('./index.js');
Server listening at: http://localhost:8080/

js:>

The shell can also be run without the need of npm using the es4x-launcher runnable jar.

java -jar es4x-launcher.jar run "js:>"

A bootstrapped shell will be available to run your code with all the components available in your classpath.

WARNING

The REPL will not be able to use MJS modules references as those are computed at initialization time.