Making desktop apps in Elixir


In my quest to make a desktop app with Elixir for Windows (I have given up the idea of doing multi-desktop apps for now) I am trying to create a HelloWorld Desktop app.

This app is basically what you get from running mix hello.
I am using Phoenix’s latest version, so I don’t have to deal with SASS nor anything alike, which honestly is a blessing since this means I don’t have any more node-gyp issues.

Making it desktop friendly

As some of you may have realized however, just creating a Phoenix project won’t make it a Desktop app.
This is where the Desktop project comes in:

This is a dependency that allows you to make your applications Desktop like.
Since I have run the Sample app in the past:

I figured I would try to tear it apart and try to launch the simplest, dummiest HelloWorld app I could.
Basically, when I run mix iex -S I want it to instead of opening a window in my browser for it to open a desktop app.


I have added all the dependencies and I have a somewhat similar project structure to what the sample app has:


defmodule Hello.Application do
  # See
  # for more information on OTP Applications
  @moduledoc false

  use Application

  @impl true
  def start(_type, _args) do
    children = [
      # Start the Telemetry supervisor
      # Start the PubSub system
      {Phoenix.PubSub, name: Hello.PubSub},
      # Start the Endpoint (http/https)
      # Start a worker by calling: Hello.Worker.start_link(arg)
      # {Hello.Worker, arg}

    # See
    # for other strategies and supported options
    opts = [strategy: :one_for_one, name: Hello.Supervisor]
    Supervisor.start_link(children, opts)

  # Tell Phoenix to update the endpoint configuration
  # whenever the application is updated.
  @impl true
  def config_change(changed, _new, removed) do
    HelloWeb.Endpoint.config_change(changed, removed)

However, nothing I do works. There are no errors in the console, but the desktop app won’t start.
I am willing to throw everything away, all I want is to have a way of opening this in a desktop window.

I think there might be a config issue, but I can’t be sure since the sample app is done with an older version of Phoenix that uses SASS.


Can someone help me figure out what is the MNE to have this open a desktop window?

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Looking at the example repo I think you also need to include a Desktop.Window child process in your supervision tree?


I already do that. Here is a link to the project:

Just looking at the code check your hello.ex you still have a reference to ‘TodoWeb’ there from the example. Replace that with HelloWeb.

{:ok, _} = Supervisor.start_child(sup, TodoWeb.Sup)

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I’ve just had a chance to check the repo out and try it. There are a couple of issues here:

  • It wasn’t using Desktop.Endpoint but Phoenix.Endpoint in your endpoint.ex
  • There are two applications in hello.ex and application.ex the only one used was application.ex but that did not start the Desktop.Window.
  • There are icons referenced that don’t exist: icon.png, icon32x32-done.png
  • config.exs did not configure the HTTP port to be 0
  • menu.eex had an <menubar> element that is not valid there.

I’ve supplied a PR to make it run:

Best to double check the supervision tree. At the moment hello.ex and sup.ex are not used, so you might either delete them or embed them in the supervision tree that is started from application.ex