Let Claude install the building tools

By the endThe building tools are installed, Claude is connected to your GitHub account, and your project has its first backup in a private repository.

Your app is built with a free toolkit called Expo. One set of files becomes an iPhone app and an Android app. Expo runs on macOS, Windows (PowerShell and WSL 2) and Linux. It needs a few free helpers on your computer:

On a Mac

Node.js, the engine that runs the tools; Git, which makes backups and comes with Apple's Command Line Tools; GitHub's own small tool, so Claude can talk to your GitHub account; and sometimes Homebrew, a tool that installs other tools.

You never open any of these. Claude installs them and uses them. Xcode is not needed for this step; it can still be downloading.

On a Windows PC

Node.js, the engine that runs the tools; Git for Windows, which makes backups and also gives Claude the command tools it prefers on a PC (when Git for Windows is installed, Claude Code runs its commands through it; without it, Claude uses PowerShell instead); and GitHub's own small tool, so Claude can talk to your GitHub account. No Homebrew, no Xcode, nothing from Apple: none of those exist for Windows, and none are needed.

You never open any of these. Each one arrives as an ordinary Windows installer, the kind the step "Download and open a file" in Part 1 showed, with the same safety boxes. Claude tells you which to download and checks each one after you run it. One PC habit to learn now: the Claude app on Windows only notices newly installed tools after you quit it completely and open it again. Claude tells you when.

Ask Claude to install everything

In your project's session in the Code tab, send this:

Copy for Claude

Please set up this computer for building my app. First read my plan file and CLAUDE.md in this folder. Then: 1. Install everything we need to build an app with Expo for iPhone and Android: Node.js, Git, GitHub's command-line tool, and whatever Expo needs. Don't install Xcode or Android Studio; we handle those later. Before each install, tell me in one plain line what it is and why we need it. 2. If a step needs my computer's password, needs me to click Yes in a Windows "allow this app to make changes" box, or needs me to answer questions, give me the command in a copy box, tell me where to paste it, and check the result yourself after I say I ran it. Never ask me for the password itself. 3. If this is a Windows PC: use the official installers from nodejs.org (the LTS version) and git-scm.com, give me the download links one at a time, and walk me through each installer's screens. Tell me when I need to quit and reopen the Claude app so you can see the new tools. Then make sure npx and git work in the Terminal pane, and fix it with me if PowerShell refuses to run scripts. 4. Connect this project to my GitHub account. Walk me through the sign-in one step at a time. 5. Create a private repository on GitHub named after my app, and make the first backup of this folder: my plan file, CLAUDE.md and notes.txt. Keep it private. 6. When you're done, tell me what's installed, what's backed up, and anything still waiting on me. I'm a beginner. One thing at a time, plain words.

What to expect

On a Mac

Ten to twenty Allow questions (step 4). Most are installs you asked for; say yes. And one to three commands handed to you (step 5):

Installing Homebrew or Node.js. The command asks for your Mac password. Type it; nothing shows.
A window pops up saying the git command needs the command line developer tools. Click Install, then Agree. It downloads for a few minutes. Then tell Claude "It finished".
Signing in to GitHub. Covered next.

On a Windows PC

A handful of Allow questions (step 4), two or three installers to click through, and one restart of the Claude app:

Node.js. Claude gives you a link to nodejs.org/en/download, the Windows Installer (.msi) for the version marked LTS. Download it, open it from Downloads, and click Next on each screen, keeping the defaults. If a screen offers to automatically install extra tools for "native modules", leave its box unticked; you don't need them. Click Install, then Yes in the Windows box, then Finish.
Git. Claude's link goes to git-scm.com/install/windows, the Git for Windows/x64 Setup (or the ARM64 Setup for Arm laptops). The installer has many screens: click Next on every screen and keep the defaults; on the 'Adjusting your PATH environment' screen keep the recommended choice. Click Yes in the Windows box when it asks.
GitHub's tool. Claude either runs a command for it after an Allow question, using winget, the installer-by-command built into Windows 11 and recent Windows 10, or gives you its installer to click through. The official ways are winget install --id GitHub.cli --source winget, or the .msi installer from cli.github.com. Either way, click Yes in the Windows box.
The restart. After the installs, Claude may say it cannot find node or git. That is expected on a PC. Quit Claude completely (step 2 of this part), open it again, click Code, click your session in the sidebar, and say: "I reopened the app. Please check the tools again."
PowerShell refusing scripts. If the Terminal pane says a file cannot be loaded because running scripts is disabled on this system, see the trouble box below.
Signing in to GitHub. Covered next.

If Claude offers to install Node.js or Git with a command instead of a download link, that is fine too: say yes to the Allow question, then click Yes in the Windows box that appears. The restart is still needed afterwards.

Claude gives you a command, usually gh auth login, for the Terminal pane. It asks questions one at a time; move with the arrow keys and press Enter (Return on a Mac). The answers: GitHub.com; HTTPS; Y (yes) to authenticating Git with your GitHub credentials; Login with a web browser; then it shows a one-time code and opens github.com/login/device.

On a Mac

The Terminal shows a one-time code of letters and numbers. Select it with the pointer and press Command + C.
Press Return. Your browser opens a GitHub page asking for the code. If it doesn't, go to github.com/login/device yourself.
Paste the code, click Continue, then Authorize. GitHub may ask for your password or a two-step code; that is GitHub's own page, so it is fine.
Back in the Terminal, a line says you are logged in. Tell Claude: "I ran it. Please read the Terminal and check."

On a Windows PC

The Terminal shows a one-time code: eight letters and numbers with a dash in the middle. Select it with the pointer and press Ctrl + C; with text selected, that copies instead of stopping anything. Or read it and type it in a moment.
Press Enter. Your browser opens a GitHub page asking for the code. If it doesn't, go to github.com/login/device yourself.
Paste or type the code, click Continue, then Authorize. GitHub may ask for your password or a two-step code; that is GitHub's own page, so it is fine.
Back in the Terminal, a line says you are logged in. Tell Claude: "I ran it. Please read the Terminal and check."

One more pop-up can appear on a PC, usually during the first backup: a browser window asking you to sign in to GitHub. That is Git Credential Manager at work: Git for Windows includes Git Credential Manager, which opens a browser window for you to sign in to GitHub the first time and then remembers it in Windows. Sign in there once, and it doesn't ask again. If it never appears, GitHub's own tool handled it, which is also fine.

The one-time code expires in minutes and Claude doesn't need it. It still stays out of the chat.

The first backup

Claude creates the repository and sends your files up. Check it yourself:

In your browser, go to github.com and sign in.
Click your profile picture at the top right, then Your repositories.
Your app's name is listed with a small Private label. Click it: your plan file and CLAUDE.md are there.

If the label says Public, tell Claude: "Make the repository private."

On a Mac

On an Intel Mac everything in this step works; Claude may pick slightly older versions of some tools, which is fine until Part 12.

On a Windows PC

On a PC with an Arm chip everything in this step works too; the installers come in an Arm version, and Claude links to the right one. Part 12 is where a PC and a Mac part ways, and the guide says so there.

Advanced

This is optional and harder: installing the tools yourself from their official pages with no help along the way, then telling Claude what you installed. On a Mac: nodejs.org, git-scm.com and cli.github.com, clicking through each installer. On a Windows PC: the same three pages, or all three in one go with winget, Windows' own installer command, in the Terminal pane, then a full quit and reopen of Claude. Same result, more clicking, and Claude can't check your choices along the way. The simple path above is better for a first app.

If something goes wrong

Claude's command fails with "command not found" or "is not recognized". The install didn't finish, or the Terminal needs a fresh start. Close the Terminal pane, open it again, and run the command once more. On a PC, also quit Claude completely and open it again; it only sees new tools after that. If it fails again, tell Claude the exact words.

On a PC, the Terminal says a file "cannot be loaded because running scripts is disabled on this system". PowerShell is refusing the helper scripts that come with Node.js. Tell Claude the exact words. It gives you one command, usually Set-ExecutionPolicy -Scope CurrentUser -ExecutionPolicy RemoteSigned, to paste in the Terminal pane and run once. It allows scripts for your account only and needs no admin rights. Then run the failed command again.

On a PC, the installer says "This app can't run on your PC". You downloaded the version for the other kind of chip. Tell Claude: "The installer says it can't run on my PC." It gives you the Arm (or x64) link instead.

On a PC, Edge or Windows warns about the download. For a file from the official page Claude linked, go through the warnings as the step "Download and open a file" in Part 1 showed: Keep, then More info and Run anyway. For anything else, stop.

The Terminal never said you are logged in. Run the command again, choose Login with a web browser, and watch for the code.

GitHub says the code is wrong or expired. Codes last a few minutes. Run the command again for a fresh one.

Claude says the backup failed. Ask: "Why did it fail, in plain words, and what do you need from me?" Usually the sign-in didn't finish.

It's taking much longer than an hour. Slow downloads. Leave it running and ask Claude: "What are we waiting on right now?"

Let Claude install the building tools

Ask Claude to install everything

What to expect

The GitHub sign-in

The first backup