Create Elm App is a zero-configuration command line tool that scaffolds, runs, and builds Elm applications, aimed at developers who want a working Elm project with hot module replacement and an optimized production build without writing webpack configuration by hand.

What it is

Create Elm App is a scaffolding and build tool for the Elm ecosystem, written in JavaScript and released under the MIT licence. It installs as a global npm or Yarn package and exposes the create-elm-app generator alongside the elm-app command line tool. The project is inspired by create-react-app and follows the same philosophy: one build dependency, no configuration files or command line options required to start, and no lock-in because the generated setup can be ejected to a custom one at any time. It uses Elm Platform, Webpack, and other projects underneath, but presents them as a single curated experience.

The concrete problem it solves is the gap between Elm's own tooling and the JavaScript and CSS pipeline most projects need. elm-make has limited support for working with JavaScript and CSS, and elm-reactor does not work with applications that rely on ports; neither offers Hot Module Replacement. Create Elm App replaces that hand-rolled setup with a development server that supports HMR and a production build that is minified and carries hashed filenames.

Key capabilities

• create-elm-app my-app generates a project containing elm.json, src/Main.elm, src/index.js, src/main.css, src/serviceWorker.js, tests/Tests.elm, and a public/ folder with index.html, favicon.ico, logo.svg, and manifest.json.
• elm-app start runs the app in development mode on http://localhost:3000, reloads the page on edits, and reports build errors and lint warnings in the console and the browser window.
• elm-app build produces a production bundle in the build folder, minified, with hashes in the filenames.
• Hot Module Replacement through Webpack, which elm-reactor and elm-make do not provide.
• Support for Elm ports, so applications that interoperate with JavaScript can be developed and built.
• elm-app eject moves the project to a custom configuration, letting the tool double as a boilerplate generator.
• Each generated project ships with a README.md user guide covering guidelines for future development.

Who uses it and how

• Elm developers starting a new single-page application; the Elm SPA example by Richard Feldman is built with Create Elm App.
• Teams that want one build dependency instead of maintaining their own Webpack, Elm, and CSS pipeline.
• Teams that outgrow the defaults, ejecting at any point to take over the configuration while keeping the tool as a boilerplate generator.
• Developers arriving from create-react-app, who get the same workflow shape: global install, create-elm-app my-app, cd my-app, elm-app start.
• Linux users, who are instructed to install the package as superuser with sudo npm install create-elm-app -g.

Getting started

Install with npm install create-elm-app -g or yarn global add create-elm-app; Node >= 8 is required. Then run create-elm-app my-app, cd my-app, and elm-app start, building for production with elm-app build.

How it compares

Among the tools the project names, create-react-app is the direct model: Create Elm App copies its one dependency, zero configuration, and no lock-in principles and applies them to Elm. Against Elm's own tooling, it fills the gaps in elm-make and elm-reactor by adding JavaScript and CSS handling, port support, Hot Module Replacement, and an optimized production build on top of Webpack.

When to use it — and when not to

Adopt it when a new Elm project needs a development server with HMR and an optimized production build, and the team accepts a global CLI install with Node >= 8 as the floor. Do not pick it if the project already has a curated Elm and Webpack pipeline, needs build customization beyond the defaults but is unwilling to eject, or cannot tolerate a global npm install or sudo on Linux. The repository carried 54 open issues at the time of writing, so the issue tracker is worth checking before committing.

npm install create-elm-app -g
create-elm-app my-app
cd my-app/
elm-app start

create-elm-app my-app
cd my-app/

my-app/
├── .gitignore
├── README.md
├── elm.json
├── elm-stuff
├── public
│   ├── favicon.ico
│   ├── index.html
│   ├── logo.svg
│   └── manifest.json
├── src
│   ├── Main.elm
│   ├── index.js
│   ├── main.css
│   └── serviceWorker.js
└── tests
    └── Tests.elm