elixir_script v0.32.1 ElixirScript View Source

ElixirScript acts as a mix compiler. This means that when you execute mix compile, ElixirScript’s compiler will run as well. Make sure to add ElixirScript to your list of compilers in mix.exs.

ElixirScript must be told which modules to use as the entry to your ElixirScript application. This is done by adding an elixir_script key to your project configuration whose value is a keyword list of options. Add an input key and make the value either the name of a module or a list of modules that are the entry modules you wish to compile to JavaScript. ElixirScript will use those modules to find what other modules and functions it needs to convert to JavaScript. ElixirScript by default places output in priv/elixir_script/build. If you wish to change this, add an output key to your ElixirScript configuration.

An example configuration for a project is shown below

    def project do
    app: :my_app,
    version: "0.1.0",
    elixir: "~> 1.0",
    deps: deps,
    # Add elixir_script as a compilter
    compilers: Mix.compilers ++ [:elixir_script],
    # Our elixir_script configuration
    elixir_script: [
        # Entry module. Can also be a list of modules
        input: MyEntryModule,
        # Output path. Either a path to a js file or a directory
        output: "priv/elixir_script/build"

Available options are:

  • input (required): The entry module(s) for your application or library

  • output: The path of the generated JavaScript files. (defaults to priv/elixir_script/build)

    This should be a directory. If given a file, it will dump JavaScript files into the same directory as the given file path

  • root: Optional root for imports of FFI JavaScript modules. Defaults to .. If using output directly in a browser, you may want to make it something like /js or some uri.

Now run mix compile and you should see a JavaScript file named elixirscript.build.js in the priv/elixir_script/build/ directory. ElixirScript outputs JavaScript in the ES Module format. If your browser supports it, you can include the output in a script tag with the type “module”

<script type="module">
  import MyEntryModule from '/js/Elixir.MyEntryModule.js'
  const myInitialArgs = []

  MyEntryModule.start(Symbol.for('normal'), myInitialArgs)

If your browser does not yet support ES modules directly, use a tool such as webpack or brunch to convert it into something that can be used in the browser

JavaScript Interop

Check out the JavaScript Interoperability documentation


ElixirScript can use many of the same Hex packages and dependencies that currently exist. It is also possible to make packages that are specific to ElixirScript. If you decide to make such a package, please prepend elixir_script to the app name. For instance is making a package for ElixirScript with FFI modules for interacting with React, the name would be elixir_script_react. This is to make sure that other developers know that a package in Hex is specifically for use with ElixirScript.


ElixirScript does not support receive or any of OTP at this time.