Get your machine ready

Setup splits three ways, so you always know who does which job. First: the apps you install on your computer, the ones that live in Applications, ask for your Apple ID, and need you to accept a licence. Second: the accounts you open with services on the web. Third: the connections that let your agent use those accounts for you.

This lesson is the first of those: the apps on your Mac and the trusted tools your agent will install. Think of it like a kitchen. You bring in the oven and the fridge yourself, because only you can sign for the delivery. Your agent stocks the pantry, labels the jars, and checks nothing has expired.

A simple rule keeps things safe. You install anything that needs your Apple ID, unlocks a permission box, or can see your whole disk. Your agent installs the developer tools inside a project folder you point it at, and it reports back on exactly what changed. That way, your files stay private and repeatable, and your agent still does the heavy lifting.

Lists are easier to trust when you see how they are decided. The install list comes from where your app will run:

• Building a website or web app only: a browser is enough. Chrome or Safari are fine, and you already have one. No extra install beyond your agent.

• Building for iPhone: Xcode. This is non-negotiable for shipping to the App Store.

• Building for Android: Android Studio. This is how Android tools arrive on your Mac.

• Building for both phones: both of the above.

On Windows: only a Mac can build an iPhone app. A Windows reader can ship to Android and rent a Mac in the cloud later for the iPhone build.

This course builds a mobile app for both phones, so you install both Xcode and Android Studio. There is also a small marketing website, which needs nothing extra because a browser covers it.

One payoff: today is the heaviest install day of the whole course, and it happens once. Later you will choose how your app gets onto a phone, and there is more than one good answer, but the choice does not change what you install today. Every route to the App Store goes through Xcode, and every route to Google Play goes through Android Studio.

Claude Desktop is where you brief your coding agent and approve changes to your project. Installing it is like setting up your workbench before you bring in any tools.

Follow the steps below on your Mac. The result should be Claude Desktop in Applications, signed in, and ready to start a new chat.

Codex is the alternative, and it also runs on your desktop: it lives inside the ChatGPT desktop app, and it comes as a command tool and an editor extension too. Either agent can do everything in this course. We show Claude Desktop because it is the simplest thing to install if you have never used a terminal, and because every prompt in these lessons was written against it. If you already live in ChatGPT or VS Code, use Codex and read the prompts as written for whichever agent you have.

This is a real decision with real money on it. Picking the lowest tier can stop you at the worst time, halfway through wiring a screen, with a cooldown clock and no way to continue.

Claude Desktop plans: see Claude's pricing page. Pro at $20 a month is too little for this course. You will run out of capacity during a build session. Max 5x at $100 a month is the recommendation. Max 20x at $200 a month is more than this course needs, fine if you are already building full time.

Codex rides on your ChatGPT plan rather than being bought separately. See ChatGPT's pricing page. Plus is $20 a month, Pro is $200 a month, and Business is about $25 per person. Claude has a middle tier at $100; ChatGPT jumps from $20 to $200, so the choice there is starker. Anyone going the Codex route on Plus should expect to hit limits on a heavy day.

Why $100 a month makes sense: a subscription is not priced like the usage behind it. The same work billed through an API, token by token, often costs several times a flat subscription in a busy month. That gap is why a flat plan is the sensible way to buy today, and pricing like this may not last.

Frame it against the alternative. It is roughly a day of a contractor’s time per month, for something you will use daily for months.

Your agent works inside a folder you choose, like a contractor who gets a key to the garage, not the whole house. That permission box is yours to click, and it is what lets the agent create files, install tools, and show you changes in one place.

Create a project folder now. Name it after your app idea. Keep it somewhere you can find easily, like Documents.

When your agent first tries to create files in that folder, macOS shows a permission box asking if the app can access it. Click OK. If it asks again later for a subfolder, allow that too. Do not grant access to your entire disk. Keeping it scoped makes audits and backups simpler.

From now on, any install your agent does will live under this folder or in standard system locations it explains first. You will approve before each change.

Xcode is the oven for iPhone builds. It comes through the Mac App Store, it is large, and it needs a first run to install extra pieces. The download can take a while, so start it now and keep reading.

You will install it, open it once, accept the licence, and let it install additional components when it asks. Your agent will verify the version after that.

Android Studio brings in the Android SDK and build tools. It comes as a Mac download, installs into Applications, and guides you through a setup wizard. Take the Standard option unless you already know otherwise.

The SDK download can take a while. Let it run and watch for green ticks at the end.

Homebrew is like a smart pantry: it fetches, labels, and updates the small tools your agent needs, all in known places. Your app needs it because many other tools ride in through it cleanly and can be checked later.

You do not run installers yourself. Ask your agent to install Homebrew, explain what it changes, and prove it works. If Homebrew is already present, your agent should confirm and move on.

Node is the engine that runs the build tools your app needs. npm comes with it, and npm is the part that fetches add-ons other people have written. Think of Node as the stovetop and npm as the shopping trip.

You installed Homebrew a moment ago, and Homebrew can install Node. That is the simplest path and it keeps everything in one place, so that is what to ask for.

There is a longer story here. Some projects need different versions of Node, and there are tools whose whole job is switching between them. You do not need one today, and you will know if you ever do, because something will complain about a version. Let your agent make the call and say why.

Ask it to confirm both Node and npm are working before moving on.

Git is a time machine for your files. It can take a snapshot, let you try a change, and return you to the snapshot if needed. You will use it to save your progress locally and, later, to share with GitHub.

Many Macs have a basic Git already present. Your agent will check, install or upgrade through Homebrew if needed, and verify the result. No need to learn Git’s commands today; saving snapshots comes later.

Your agent forgets a conversation. It does not forget a file. Now that it has a folder to work in and Git on the machine, you can write down how you want it to work, and it will read that before it starts, every time, without you asking.

Most agents look for a file called AGENTS.md or CLAUDE.md in your project. Think of it as the note you leave for someone working in your house while you are out.

The single most valuable rule to put in it today is about saving your work. Ask the agent to commit after every change that works, with a message saying what changed. A commit is a labelled snapshot of the whole project, and a project with frequent commits can be wound back to any of them.

Two more earn their place on day one. Have it find where something lives before it changes it, and have it stick to the one job you asked for. Both are habits you would otherwise be typing into every conversation for the rest of the course.

This is the difference between a bad afternoon and a lost one. When something breaks in an hour's time, and it will, the question is how far back the last good state is. With commits after each working change, the answer is minutes. Without them, the answer is however long ago you last remembered to save something, which is usually this morning.

Module 3 covers what commits actually are and how to read your own history. Today you are only making sure they happen.

Only do this section if you are building with React Native, which is what this course uses and what the next modules assume. If you already know you are taking a different route to the app stores, skip it: your agent installs that route's tools when you get there, and nothing else from today changes. You choose properly in the next module, and installing Expo now costs you nothing if you switch.

Expo is the set of tools that creates a new React Native app, starts it on your phone, and refreshes it while you edit. Picture a director calling action, then keeping the scene in sync while you move the lights around.

Your agent installs the Expo command so it can create and run projects from your folder, then checks the command actually works. There is more than one way to install it, so let the agent pick and explain.

Any time you need another tool later, focus on the outcome. “I want to compress images in my build” beats “install X.” You are hiring a helper, not ordering a part number.

A good install request has a shape:

• Say what you want to be able to do and where (in this project folder).

• Say you are not a developer and need plain language.

• Ask the agent to check what is already there first.

• Ask it to explain as it goes, and to show changes before making them.

• Ask it to verify at the end with a short, human check.

• Tell it to stop and explain rather than push on if something fails.

That set of asks prevents silent changes and gives you proof it worked.

Failure is part of setup. An install can hang, a permission can be missing, or a download can be blocked by a corporate network. Your move is not to poke around menus. Your move is to tell the agent what happened, with the full error, and ask for a plan.

Short, vague messages make bad help. Full errors make good help. Include screenshots if the app shows a dialog with a red stop sign. Say exactly which step you were on and what button you clicked.

Then let the agent decide: retry, change approach, or wait. If the failure is on a provider’s side, like a temporary outage, your agent will tell you to pause. If it is on your machine, it will ask you for the one or two permission clicks only you can do.