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The Ruby runtime runs bots, workers, APIs and Rails websites. Square Cloud installs your gems with Bundler and starts your app with Ruby.

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Before you begin

  • Ruby on your machine. If you don’t have it yet, download it from the official Ruby website, or use version managers like rbenv or rvm.
  • A Square Cloud account: sign up with your email or GitHub.
  • An active plan. See the plans and pick the one that fits your project.

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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

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What Square Cloud runs

  • If the START field is not defined in the configuration file, Square Cloud will execute ruby MAIN, where the file specified in MAIN is the Ruby file (e.g. main.rb). If the START field is defined, the value in it will be executed directly. It is common to define START as bundle exec ruby main.rb or another suitable startup command. For more information about configuration file parameters, visit configuration parameters.
  • Before starting the app, Square Cloud runs bundle install to install the gems listed in your Gemfile.
  • The runtime sets RACK_ENV=production, so Rack apps such as Rails and Sinatra start in production mode.
Bundler reads its settings from environment variables, which are loaded before bundle install runs. To exclude unnecessary gem groups in production, configure the variable BUNDLE_WITHOUT=development:test.

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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 server must listen on that port and on all network interfaces. Rails does it with no changes in production; with Puma or Sinatra, read ENV.fetch("PORT", 80) and bind to 0.0.0.0.

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Prepare the project

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Required files

  • squarecloud.app, at the root of the ZIP.
  • main.rb, or the file set in MAIN: your Ruby entry point.
  • Gemfile, required: an upload without it fails with INVALID_DEPENDENCY.
  • Gemfile.lock, generated by Bundler: include it so the server installs the same gem versions.
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

  • vendor/bundle and .bundle: gems installed for your machine. Square Cloud runs bundle install on the server.
  • log/ and tmp/, when your app creates them.

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Framework guides

Ruby on Rails

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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.