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The Elixir runtime runs Mix projects: bots, workers, APIs and Phoenix websites. Square Cloud fetches your dependencies and compiles your project on the server.

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Before you begin

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Configure Square Cloud

If you upload your application through the dashboard, you can skip this section: the dashboard creates the squarecloud.app configuration file for you.

Configuration file reference

The squarecloud.app file tells Square Cloud how to run your application: its main file, memory, runtime version, name and, for a website, its subdomain.
A complete configuration file for each kind of app:
squarecloud.app
The website example starts a Phoenix app; the Phoenix guide covers its assets and environment variables.

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What Square Cloud runs

  • If the START field is not defined in the configuration file, Square Cloud will execute mix run --no-halt to start the project. If the START field is defined, the value in it will be executed directly. For more information about configuration file parameters, visit configuration parameters.
  • Before START, Square Cloud installs the hex and rebar tools locally and fetches project dependencies with mix deps.get. If one of these steps fails, the app does not start.
  • MAIN only tells Square Cloud that the project is written in Elixir: it must point to an existing .ex or .exs file (for example mix.exs), while mix run --no-halt runs your whole Mix project.

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Port and host for websites and APIs

Square Cloud sets the PORT environment variable to 80 and HOST to 0.0.0.0. Your web server must listen on that port and on all network interfaces. Phoenix does it in production with the config/runtime.exs it generates; with Plug or Bandit, read System.get_env("PORT") when you start the server.

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Prepare the project

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Required files

  • squarecloud.app, at the root of the ZIP.
  • mix.exs, required: an upload without it fails with INVALID_DEPENDENCY.
  • mix.lock, so the server fetches the same dependency versions as your machine.
  • Your source code, usually in lib/ and config/.
The configuration file (squarecloud.app) must be located at the root of the zip file. Otherwise, Square Cloud will not be able to find it during deploy.

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What to leave out

  • _build/: files compiled for your machine. Square Cloud compiles the project on Linux.
  • deps/: mix deps.get fetches the dependencies again on the server.

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Framework guides

Phoenix

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Deploy

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Via dashboard

1

Access the Upload Page

Access the upload page and upload your project zip file.
2

Configure Your Environment

After uploading your zip, you will need to configure the name, main file or runtime environment and other settings for your project.
If you are uploading a web project, make sure to select “Web Publication” and set a subdomain to your project.
3

Deploy Your Project

Finally, click on the “Deploy” button to host your project on Square Cloud.
After deployment, you can monitor your project’s status and logs from the dashboard.
Uploading application to Square Cloud
4

Confirm Your App Is Live

Your first deploy usually takes less than a minute. In the dashboard, wait for your application status to show as running and check the logs for any startup errors.
If you deployed a website or API, open https://<your-subdomain>.squareweb.app in your browser: you should see your application responding. If you deployed a bot, send it a command to confirm it is online.
App not starting? See the Troubleshooting guide for the most common causes and fixes.

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Via CLI

To use this method, your project needs a configuration file named squarecloud.app at its root. It tells Square Cloud how to run your application.

Configuration file guide

Learn how to create the squarecloud.app configuration file that defines your application’s environment.
1

Install the CLI

Install the Square Cloud CLI. If you already have it, run the same command to update it:
2

Log In

Run the command below. It opens your browser: approve the login there and the CLI is ready. There is no API key to copy. For scripts and CI, see CLI authentication.
3

Upload Your Project

From your project folder, run the command below. The CLI zips the current folder, leaving out what squarecloud.ignore lists, and uploads it:
To upload a zip you created yourself, pass it with --file:
4

Confirm Your App Is Live

Your first deploy usually takes less than a minute. Check your application status and logs directly from the terminal:
If you deployed a website or API, open https://<your-subdomain>.squareweb.app in your browser: you should see your application responding. If you deployed a bot, send it a command to confirm it is online.
App not starting? See the Troubleshooting guide for the most common causes and fixes.

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Next steps

Environment variables

Keep secrets and settings out of your code and read them at runtime.

Custom domain

Serve your app on your own domain, on the Standard plan and above.

Troubleshooting

Fix an app that does not start or a site that does not respond.

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Contact us

If you continue facing technical difficulties, our specialized support team is available to assist you. Contact us and we’ll be happy to help you resolve any issue: support quality is a big part of why developers rate Square Cloud 4.9/5 across 402 reviews on Google and Trustpilot.