What is Claude Code? Install it and run your first session, no coding needed

Claude Code is Anthropic's AI coding assistant. You describe a task in plain English; it reads the files in your project folder, writes or edits them, and runs commands to check its work. To install it you need macOS 13 or Windows 10 (version 1809) or later, a paid Claude plan, and one line pasted into a terminal.

I'm Hai Le, a UI/UX designer who writes code. I built this site with Next.js and Claude Code, and the repo carries instruction files Claude reads at the start of every session. This guide is for designers and anyone else who has never touched a terminal. Every command below is copied from Anthropic's documentation, checked on 2026-10-04.

How is Claude Code different from Claude in the browser?

Claude at claude.ai is a chat window. You paste something in, it answers, and you carry the answer wherever it needs to go.

Claude Code works inside a folder on your machine. It opens files on its own, creates new ones, and runs commands to see whether things work. You assign the work and review the changes.

For a designer, that means you can say "build this landing page from my layout" and get back a folder of working code you can open in a browser. My own loop from Figma to a running page is in Claude Code for designers.

What do you need before installing?

The free claude.ai plan doesn't include Claude Code, so upgrade first if you need to.

To check your macOS version, open the Apple menu and choose About This Mac.

What is a terminal, and where is it?

A terminal is a text-only window. You type a command, press Enter, and the computer prints the result. You can't click inside it; you move with the keyboard and arrow keys.

Three habits will save you most of the trouble:

• Paste the whole line exactly. One missing character breaks the command.
• Paste with Cmd + V on macOS, or Ctrl + V or right-click in Windows PowerShell.
• When the docs say "open a new terminal window", do it. Some changes only take effect in a fresh window.

macOS: press Cmd + Space, type Terminal, press Enter.

Windows: press Win + X and choose Windows PowerShell or Terminal. Windows has two command-line programs, PowerShell and CMD, and they take different commands. This guide uses PowerShell. Its prompt starts with PS C:\Users\YourName>; if there's no PS, you're in CMD.

How do you install it on a Mac?

1. Open Terminal.
2. Paste this line and press Enter:

curl -fsSL https://claude.ai/install.sh | bash

3. Wait for the text to stop scrolling. On success you'll see Claude Code successfully installed!
4. Close the window, open a new one, and check:

claude --version

A version number followed by (Claude Code) means you're done. If you get command not found: claude, jump to the errors section.

If you already use Homebrew, brew install --cask claude-code works too. Homebrew installs don't update themselves, so you'll need brew upgrade claude-code now and then. The curl install above updates in the background.

How do you install it on Windows?

1. Optional: install Git for Windows from git-scm.com/downloads/win, clicking Next through the defaults. Without it, Claude Code uses PowerShell for shell commands. You won't need to learn Git.
2. Open PowerShell with Win + X. Administrator rights aren't needed.
3. Paste this line and press Enter:

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

4. When you see Claude Code successfully installed!, close PowerShell, open a new window, and run claude --version.

Avoid the Start menu entry called Windows PowerShell (x86). It runs as a 32-bit process, which Claude Code doesn't support.

What does a safe first session look like?

Claude Code works in whatever folder you start it from. For the first run, make an empty folder so nothing important is in reach. These three commands work in macOS Terminal and in PowerShell:

mkdir claude-sandbox
cd claude-sandbox
claude

mkdir makes the folder, cd moves into it, and claude starts Claude Code.

On first launch, a browser window opens so you can sign in to your Claude account. Come back to the terminal afterwards and you'll see a prompt with the version, the current model and the working folder above it.

Then ask for something in plain words. The terminal guide in Anthropic's docs suggests this one:

make me a simple webpage that says hello world

If Claude asks permission before creating a file, press Enter to choose Yes. When it's done, open the folder in Finder or File Explorer and double-click the HTML file to see it in your browser.

Keys and commands worth remembering:

To pick up the most recent conversation in the same folder later, run claude -c.

What if the install fails?

PATH fix on macOS, where Zsh is the default shell:

echo 'export PATH="$HOME/.local/bin:$PATH"' >> ~/.zshrc
source ~/.zshrc

PATH fix on Windows, in PowerShell:

$currentPath = [Environment]::GetEnvironmentVariable('PATH', 'User')
[Environment]::SetEnvironmentVariable('PATH', "$currentPath;$env:USERPROFILE\.local\bin", 'User')

Then close the terminal, open a new one, and try claude again. If it still fails, claude doctor prints install diagnostics and suggested fixes without starting a session.

Can you skip the terminal entirely?

Yes. Anthropic ships a desktop app for macOS and Windows, a VS Code extension, and a web version at claude.ai/code. I'd still try the terminal once. Most guides assume it, and seeing the raw commands makes it easier to follow what Claude is doing.

What should you try next?

Rebuild one screen you've already designed in Figma. You'll notice quickly that the AI picks its own colours and fonts. The fix is to hand it a written description of your design system, which I cover in what DESIGN.md is.

After that, connect Claude Code to Figma so it can read tokens and components directly: see Figma MCP with Claude Code. And if you're curious how Figma's own prompt-to-prototype tool compares, read what Figma Make is.

My client work, such as Joyme, still starts with research and Figma long before any code. Claude Code speeds up the stretch after that. If you'd like to know how I work, read more about me.

Sources

• Claude Code docs: Advanced setup: system requirements, install commands, required accounts, claude doctor. Accessed 2026-10-04.
• Claude Code docs: Quickstart: login, first session, auto mode, essential commands.
• Claude Code docs: Terminal guide for new users: opening a terminal, PATH fixes, common errors.
• Claude Code docs: Troubleshoot installation and login.
• Anthropic: Supported countries and regions.