How to add a Homebrew tap

Homebrew taps are additional Git repositories that provide formulae, casks, or external Homebrew commands outside the package sources already known to the active prefix. Adding a tap is common when a project publishes its own package source or when a vendor keeps packages separate from homebrew/core and homebrew/cask.

The short tap form uses user/repo and assumes a GitHub repository named user/homebrew-repo. A project can also provide a full Git URL for taps hosted elsewhere, but the visible Homebrew tap name remains the value that later appears in brew tap and fully qualified package names.

Non-official taps can contain Ruby package definitions and external commands that Homebrew may load during package operations. Homebrew 6 separates adding a tap from trusting its contents, so inspect the tap after cloning it and trust only the specific formula, cask, or command needed for short-name installs unless the entire tap is under your control.

1. Confirm the tap name from the project or vendor documentation.

   For GitHub taps, symfony-cli/tap maps to the repository named symfony-cli/homebrew-tap. For a custom Git remote, use the full URL supplied by the project as the second argument to brew tap.

2. Add the tap to Homebrew.

   $ brew tap symfony-cli/tap
   ==> Tapping symfony-cli/tap
   Cloning into '/opt/homebrew/Library/Taps/symfony-cli/homebrew-tap'...
   Tapped 1 formula (13 files, 140.7KB).

   Replace symfony-cli/tap with the tap named by the package documentation. On Linux or WSL, the clone path usually starts with /home/linuxbrew/.linuxbrew instead of /opt/homebrew.

3. List installed taps and confirm the new tap appears.

   $ brew tap
   homebrew/core
   symfony-cli/tap

4. Inspect the tap details and trust state.

   $ brew tap-info symfony-cli/tap
   symfony-cli/tap: Installed
   Untrusted
   1 formula
   /opt/homebrew/Library/Taps/symfony-cli/homebrew-tap (13 files, 140.7KB)
   From: https://github.com/symfony-cli/homebrew-tap
   ==> Formulae
   symfony-cli

   Untrusted means Homebrew has not been told to load non-official package code from this tap for short-name operations. Trust only taps or packages that you would allow to run Ruby code with your user permissions.

5. Check a package from the tap by fully qualified name.

   $ brew info symfony-cli/tap/symfony-cli
   ==> symfony-cli/tap/symfony-cli: stable 5.17.1
   Symfony CLI helps Symfony developers manage projects, from local code to remote infrastructure
   https://symfony.com
   Not installed
   From: https://github.com/symfony-cli/homebrew-tap/blob/HEAD/Formula/symfony-cli.rb
   Tap: symfony-cli/tap

   A fully qualified name keeps the lookup tied to the tapped repository, which matters when another tap or homebrew/core has a similar token.
   Related: How to check Homebrew package information

6. Trust the specific tapped formula when short-name installs are required.

   $ brew trust --formula symfony-cli/tap/symfony-cli
   Trusted formula: symfony-cli/tap/symfony-cli

   For casks, use brew trust --cask user/repo/cask. Trusting user/repo without --formula or --cask trusts the whole tap, including future package definitions.

7. List trusted entries before installing by short name.

   $ brew trust
   All official taps and commands are trusted.
   Trusted formulae:
     symfony-cli/tap/symfony-cli

   After this check, install with brew install symfony-cli/tap/symfony-cli to stay fully qualified, or brew install symfony-cli only when the specific formula is trusted.
   Related: How to install a Homebrew formula