To further accelerate AI development (Vibe Coding, Agentic Coding, etc.), I’ve started working with three MacBooks in full rotation. Since I had the chance to set one up from scratch, here’s the process documented as a reference.

Step 1: Xcode Command Line Tools

Run the following in the Terminal on a fresh macOS installation:

xcode-select --install

This gives you the system git. Homebrew will also trigger this automatically, but doing it beforehand helps avoid issues.

After installation, verify that git is available:

git --version

Step 2: Install Homebrew

Install Homebrew, the package manager for macOS. Run the one-liner from the official website:

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

After installation, follow the Next steps instructions shown in the terminal to add Homebrew to your PATH.

Step 3: Install GitHub CLI and Log In

Install GitHub CLI via Homebrew and authenticate. This is needed to clone repositories in the next step.

brew install gh
gh auth login

Step 4: Bulk Install with Brewfile

I manage all my tools and applications in a Brewfile. My Brewfile is publicly available in the oh-my-config repository. Clone it and run brew bundle to install everything at once.

gh repo clone shige/oh-my-config
cd oh-my-config/homebrew/
brew bundle

brew bundle installs all packages listed in the Brewfile — brew formulae, cask applications, and mas (Mac App Store) apps. With a single command, a fresh Mac gets a fully equipped development environment.

Summary

Setting up a new MacBook is nearly automated as long as you maintain a Brewfile. Here’s the process at a glance:

1. Install Xcode Command Line Tools to get git
2. Install Homebrew
3. Install GitHub CLI and log in
4. Bulk install all tools and apps with Brewfile

As long as you keep your Brewfile up to date, you can set up any new Mac without hesitation. Keeping a Brewfile maintained and documenting the steps saves you from the “what was that again?” moments every time you set up a new machine.

That’s all from the Gemba, where we set up a three-MacBook development environment.