Install the toolchain on Windows

Three installs on the laptop, one on the phone. None of them cost anything, and none of them need an account yet.

This lesson is written for Windows first because most people reading it are on Windows. Mac and Linux panels are there where the command differs.

Node

Node is the thing that runs the JavaScript toolchain. You will almost never talk to it directly, but nothing else works without it.

Download the LTS installer from nodejs.org and run it, accepting the defaults. It is a normal Windows installer with a Next button.

Version-pinned, verified 2026-09-04. Expo SDK 57 requires Node 22.13.x or newer. The current LTS build is comfortably above that, but check the number rather than assuming.

node -v

A version starting with v22.13 or higher. If the number is lower, or the command is not recognised, the installer did not finish or you are in a terminal window that was open before it ran.

Git for Windows

This one looks optional and is not. Claude Code uses Git Bash for its shell commands on Windows when Git for Windows is installed, and falls back to PowerShell when it is not. Almost every command in a course, a forum answer or a documentation page assumes the first, so installing Git now removes an entire category of "the commands in the lesson do not work on my machine".

Download it from git-scm.com and run the installer with its defaults.

git --version

Something like git version 2.51.0.windows.1. Any version is fine — you are checking it exists, not which one.

While you are here, one small thing that trips up more beginners than it should: PowerShell shows a prompt beginning PS C:\, and Command Prompt shows C:\ without the PS. They are different programs with different rules. When a lesson says PowerShell, look at the start of your prompt and make sure that is what you are in.

Claude Code

irm https://claude.ai/install.ps1 | iex

Close the terminal and open a new one. Installers add Claude Code to your PATH, and a window that was already open does not know that. This one step is the cause of most "it says it is not recognised" messages.

claude --version

A version number on the 2.1 line. If you get 'not recognized' or 'command not found', you are still in the old window.

Installing is free. Signing in is not — that is the account from lesson 1, and you do not need it until lesson 4. You can finish this lesson and the next one without ever running claude on its own.

Expo Go, on the phone

One install on the phone, from the Play Store: Expo Go. That is all the phone-side setup there is. No developer mode, no USB cable, no unlocking anything.

Expo Go is a container app: your code runs inside it over your Wi-Fi, which is why lesson 3 takes fifteen minutes instead of an afternoon. It has limits — it cannot show your own app icon or app name, and it cannot use native libraries that were not built into it — and you meet those in module 4, at the point where they start to matter.

There is no emulator in this course

Said out loud here so you do not go looking for one.

An Android emulator means installing Android Studio, which idles at two to three gigabytes of memory, and then running a virtual phone that wants another two to four. On an 8GB Windows laptop — which is what a lot of people reading this have — that leaves nothing for the operating system and a browser, and the machine starts swapping to disk. Sixteen gigabytes is the practical floor.

It is also a documented time sink: a public report on Anthropic's issue tracker from April 2026 describes a Windows user losing four hours to Claude Code trying and failing to set up an Android emulator, before a single line of app code was written.

So the phone in your pocket is the test device for this entire course. Do not install Android Studio. That is not a compromise — a real phone is a better test surface than a simulated one, and it is the thing you can hand to someone across a table.

A word about WSL

WSL, the Linux environment inside Windows, exists and is genuinely good for other kinds of work. Do not route this course through it. It puts a separate filesystem and network layer between your project and your phone, and the QR-code connection in the next lesson is exactly what that layer breaks.