Note: Before taking the time to craft a new cask, make sure

• it can be accepted by checking the Rejected Casks FAQ document,
• check if there are no open pull requests for the same cask and
• check if the cask was not already refused.

Adding a Cask

Making a new Cask is easy. Follow the directions in Getting Set Up To Contribute to begin.

Examples

Here’s a Cask for shuttle as an example. Note the comment above url, which is needed when the url and homepage hostnames differ

cask "shuttle" do
  version "1.2.9"
  sha256 "0b80bf62922291da391098f979683e69cc7b65c4bdb986a431e3f1d9175fba20"

  url "https://github.com/fitztrev/shuttle/releases/download/v#{version}/Shuttle.zip",
      verified: "github.com/fitztrev/shuttle/"
  appcast "https://github.com/fitztrev/shuttle/releases.atom"
  name "Shuttle"
  desc "Simple shortcut menu"
  homepage "https://fitztrev.github.io/shuttle/"

  app "Shuttle.app"

  zap trash: "~/.shuttle.json"
end

And here is one for advancedcolors. Note that it has an unversioned download (the download url does not contain the version number, unlike the example above). It also suppresses the checksum with sha256 :no_check, which is necessary because the checksum will change on the same url when a new distribution is made available.

cask "advancedcolors" do
  version "1.0.0"
  sha256 :no_check

  url "https://advancedcolors.com/AdvancedColors.zip"
  name "Advanced Colors"
  desc "Lightning fast swatch tool for designers and developers"
  homepage "https://advancedcolors.com/"

  app "AdvancedColors.app"
end

Here is a last example for airdisplay, which uses a pkg installer to install the application instead of a stand-alone application bundle (.app). Note the uninstall pkgutil stanza, which is needed to uninstall all files which were installed using the installer.

You will also see how to adapt version to the download url. Use our custom version methods to do so, resorting to the standard Ruby String methods when they don’t suffice.

cask "airdisplay" do
  version "3.4.2"
  sha256 "272d14f33b3a4a16e5e0e1ebb2d519db4e0e3da17f95f77c91455b354bee7ee7"

  url "https://www.avatron.com/updates/software/airdisplay/ad#{version.no_dots}.zip"
  appcast "https://www.avatron.com/updates/software/airdisplay/appcast.xml"
  name "Air Display"
  desc "Utility for using a tablet as a second monitor"
  homepage "https://avatron.com/applications/air-display/"

  depends_on macos: ">= :mojave"

  pkg "Air Display Installer.pkg"

  uninstall pkgutil: [
    "com.avatron.pkg.AirDisplay",
    "com.avatron.pkg.AirDisplayHost2",
  ]
end

Generating a Token for the Cask

The Cask token is the mnemonic string people will use to interact with the Cask via brew install, etc. The name of the Cask file is simply the token with the extension .rb appended.

The easiest way to generate a token for a Cask is to run this command:

$ "$(brew --repository)/Library/Taps/homebrew/homebrew-cask/developer/bin/generate_cask_token" '/full/path/to/new/software.app'

If the software you wish to Cask is not installed, or does not have an associated App bundle, just give the full proper name of the software instead of a pathname:

$ "$(brew --repository)/Library/Taps/homebrew/homebrew-cask/developer/bin/generate_cask_token" 'Google Chrome'

If the generate_cask_token script does not work for you, see Cask Token Details.

The brew create --cask Command

Once you know the token, create your Cask with the handy-dandy brew create --cask command:

$ brew create --cask download-url --set-name my-new-cask

This will open $EDITOR with a template for your new Cask, to be stored in the file my-new-cask.rb. Running the create command above will get you a template that looks like this:

cask "my-new-cask" do
  version ""
  sha256 ""

  url "download-url"
  name ""
  desc ""
  homepage ""

  app ""
end

Cask Stanzas

Fill in the following stanzas for your Cask:

Other commonly-used stanzas are:

Additional artifact stanzas you might need for special use-cases can be found here. Even more special-use stanzas are listed at Optional Stanzas.

Cask Token Details

If a token conflicts with an already-existing Cask, authors should manually make the new token unique by prepending the vendor name. Example: unison.rb and panic-unison.rb.

If possible, avoid creating tokens which differ only by the placement of hyphens.

To generate a token manually, or to learn about exceptions for unusual cases, see token_reference.md.

Archives With Subfolders

When a downloaded archive expands to a subfolder, the subfolder name must be included in the app value.

Example:

1. Texmaker is downloaded to the file TexmakerMacosxLion.zip.
2. TexmakerMacosxLion.zip unzips to a folder called TexmakerMacosxLion.
3. The folder TexmakerMacosxLion contains the application texmaker.app.
4. So, the app stanza should include the subfolder as a relative path:

app "TexmakerMacosxLion/texmaker.app"

Testing Your New Cask

Give it a shot with:

export HOMEBREW_NO_AUTO_UPDATE=1
brew install my-new-cask

Did it install? If something went wrong, edit your Cask with brew edit my-new-cask to fix it.

Test also if the uninstall works successfully:

brew uninstall my-new-cask

If everything looks good, you’ll also want to make sure your Cask passes audit with:

brew audit --new-cask my-new-cask

You should also check stylistic details with brew style:

brew style --fix my-new-cask

Keep in mind all of these checks will be made when you submit your PR, so by doing them in advance you’re saving everyone a lot of time and trouble.

If your application and Homebrew Cask do not work well together, feel free to file an issue after checking out open issues.

Finding a Home For Your Cask

We maintain separate Taps for different types of binaries. Our nomenclature is:

• Stable: The latest version provided by the developer defined by them as such.
• Beta, Development, Unstable: Subsequent versions to stable, yet incomplete and under development, aiming to eventually become the new stable. Also includes alternate versions specifically targeted at developers.
• Nightly: Constantly up-to-date versions of the current development state.
• Legacy: Any stable version that is not the most recent.
• Regional, Localized: Any version that isn’t the US English one, when that exists.
• Trial: Date-limited version that stops working entirely after it expires, requiring payment to lift the limitation.
• Freemium: Gratis version that works indefinitely but with limitations that can be removed by paying.
• Fork: An alternate version of an existing project, with a based-on but modified source and binary.
• Unofficial: An allegedly unmodified compiled binary, by a third-party, of a binary that has no existing build by the owner of the source code.
• Vendorless: A binary distributed without an official website, like a forum posting.
• Walled: When the download URL is both behind a login/registration form and from a host that differs from the homepage.
• Font: Data file containing a set of glyphs, characters, or symbols, that changes typed text.
• Driver: Software to make a hardware peripheral recognisable and usable by the system. If the software is useless without the peripheral, it’s considered a driver.

Stable Versions

Stable versions live in the main repository at Homebrew/homebrew-cask. They should run on the latest release of macOS or the previous point release (High Sierra and Mojave as of late 2018).

But There Is No Stable Version!

When an App is only available as beta, development, or unstable versions, or in cases where such a version is the general standard, then said version can go into the main repo.

Beta, Unstable, Development, Nightly, or Legacy

When an App has a main stable version, alternative versions should be submitted to Homebrew/homebrew-cask-versions.

Regional and Localized

When an App exists in more than one language or has different regional editions, the language stanza should be used to switch between languages or regions.

Trial and Freemium Versions

Before submitting a trial, make sure it can be made into a full working version without the need to be redownloaded. If an App provides a trial but the only way to buy the full version is via the Mac App Store, it does not belong in any of the official repos. Freemium versions are fine.

Forks and Apps with Conflicting Names

Forks must have the vendor’s name as a prefix on the Cask’s file name and token. If the original software is discontinued, forks still need to follow this rule so as to not be surprising to the user. There are two exceptions which allow the fork to replace the main cask:

• The original discontinued software recommends that fork.
• The fork is so overwhelmingly popular that it surpasses the original and is now the de facto project when people think of the name.

For unrelated Apps that share a name, the most popular one (usually the one already present) stays unprefixed. Since this can be subjective, if you disagree with a decision, open an issue and make your case to the maintainers.

Unofficial, Vendorless, and Walled Builds

We do not accept these casks since they offer a higher-than-normal security risk.

Fonts

Font Casks live in the Homebrew/homebrew-cask-fonts repository. See the font repo CONTRIBUTING.md for details.

Drivers

Driver Casks live in the Homebrew/homebrew-cask-drivers repository. See the drivers repo CONTRIBUTING.md for details.

Submitting Your Changes

Hop into your Tap and check to make sure your new Cask is there:

$ cd "$(brew --repository)"/Library/Taps/homebrew/homebrew-cask
$ git status
# On branch master
# Untracked files:
#   (use "git add <file>..." to include in what will be committed)
#
#       Casks/my-new-cask.rb

So far, so good. Now make a feature branch my-new-cask-branch that you’ll use in your pull request:

$ git checkout -b my-new-cask-branch
Switched to a new branch 'my-new-cask-branch'

Stage your Cask with:

$ git add Casks/my-new-cask.rb

You can view the changes that are to be committed with:

$ git diff --cached

Commit your changes with:

$ git commit -v

Commit Messages

For any git project, some good rules for commit messages are:

• The first line is commit summary, 50 characters or less,
• Followed by an empty line,
• Followed by an explanation of the commit, wrapped to 72 characters.

See a note about git commit messages for more.

The first line of a commit message becomes the title of a pull request on GitHub, like the subject line of an email. Including the key info in the first line will help us respond faster to your pull.

For Cask commits in the Homebrew Cask project, we like to include the Application name, version number, and purpose of the commit in the first line.

Examples of good, clear commit summaries:

• Add Transmission.app v1.0
• Upgrade Transmission.app to v2.82
• Fix checksum in Transmission.app Cask
• Add CodeBox Latest

Examples of difficult, unclear commit summaries:

• Upgrade to v2.82
• Checksum was bad

Pushing

Push your changes from the branch my-new-cask-branch to your GitHub account:

$ git push {{my-github-username}} my-new-cask-branch

If you are using GitHub two-factor authentication and set your remote repository as HTTPS you will need to set up a personal access token and use that instead of your password. Further information here.

Filing a Pull Request on GitHub

a) suggestion from git push

The git push command prints a suggestion to create a pull request:

remote: Create a pull request for 'new-cask-cask' on GitHub by visiting:
remote:      https://github.com/{{my-github-username}}/homebrew-cask/pull/new/my-new-cask-branch

b) use suggestion at Github website

Now go to the homebrew-cask GitHub repository. GitHub will often show your my-new-cask-branch branch with a handy button to Compare & pull request.

c) manually create a pull request at Github website

Otherwise, click the New pull request button and choose to compare across forks. The base fork should be Homebrew/homebrew-cask @ master, and the head fork should be my-github-username/homebrew-cask @ my-new-cask-branch. You can also add any further comments to your pull request at this stage.

Congratulations!

You are done now, and your Cask should be pulled in or otherwise noticed in a while. If a maintainer suggests some changes, just make them on the my-new-cask-branch branch locally and push.

Cleaning up

After your Pull Request is submitted, you should get yourself back onto master, so that brew update will pull down new Casks properly:

cd "$(brew --repository)"/Library/Taps/homebrew/homebrew-cask
git checkout master

if you set the variable HOMEBREW_NO_AUTO_UPDATE then clean it up with:

unset HOMEBREW_NO_AUTO_UPDATE