Claude CodeLesson 2 of 25

Quick Start & Installation

Claude Code installs in under a minute and works on Mac, Windows, and Linux. This lesson walks you from zero to your first working session in four steps.

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Before You Start

You need three things. All of them are free.

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A Claude account

A free account at claude.ai is all you need. Claude Code opens your browser on first run to log you in.

Sign up free at claude.ai →
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A terminal

Terminal on Mac/Linux, PowerShell or Command Prompt on Windows. No other dependencies are required — the installer handles everything.

No Node.js needed. Claude Code now ships a native installer. The installer bundles all its own dependencies — just run the command for your platform below.
Windows users — Git for Windows is recommended. Claude Code uses a Bash tool internally. If Git for Windows is installed, Claude Code uses Bash. If not, it falls back to PowerShell instead. WSL setups do not need Git for Windows.
1

Install Claude Code

Pick your platform. Anthropic's native installer sets everything up with one command — no Node.js or package managers required.

macOS, Linux, WSL:

bash
$ curl -fsSL https://claude.ai/install.sh | bash
✓ Claude Code installed successfully
$ claude --version
1.x.x

Windows PowerShell:

PowerShell
$ irm https://claude.ai/install.ps1 | iex
✓ Claude Code installed successfully

Windows CMD:

Command Prompt
$ curl -fsSL https://claude.ai/install.cmd -o install.cmd && install.cmd
✓ Claude Code installed successfully

After the install finishes, open a new terminal window and run claude --version to confirm it worked.

2

Authenticate

Run claude for the first time. It will open your browser automatically so you can log in with your Claude account. You only do this once.

Terminal — First run
$ claude
Opening browser for authentication...
Waiting for login...
✓ Authenticated as you@email.com
Claude Code ready. What would you like me to do?
> _

What the browser shows

claude.ai/auth/cli
C

Authorize Claude Code

Claude Code is requesting access to your Claude account. This lets it use Claude on your behalf from the terminal.

You will be redirected back to your terminal.

You only authenticate once. Claude Code saves your credentials securely. Every future session on this machine starts instantly — no login required.
3

Navigate to a Project

Claude Code works inside a specific folder — it reads all the files in that folder. Navigate to any existing project or create a fresh one.

Terminal — Navigate
# Option A: use an existing project
$ cd ~/my-project
# Option B: create a fresh folder to try it out
$ mkdir claude-test && cd claude-test
$ claude
Claude Code ready. What would you like me to do?
Tip: Always run claude from inside your project folder — not from your home directory. Claude uses the current folder as its workspace.
4

Your First Task

Give Claude a simple, concrete instruction. Here is a great first task to confirm everything is working: ask it to create a file.

Terminal — First task
> Create a file called hello.txt. Write inside it: Hello from Claude Code!
• Creating hello.txt...
✓ Created hello.txt
Anything else?
> Now show me the contents of hello.txt
• Reading hello.txt...
Hello from Claude Code!

Check your folder — hello.txt will be there.

What just happened

📝

Claude created a real file on your machine — not a preview, not a copy-paste.

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It then read the file back to verify the content was written correctly.

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You communicated in plain English — no commands, no syntax to learn.

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Common Issues

If something does not work, check these first.

curl: command not found (Windows CMD)

curl ships with Windows 10 build 1803+. If you are on an older version, use the PowerShell or WinGet install method instead.

Permission denied / cannot write to /usr/local

On Mac/Linux, the installer may need elevated permissions. Run it with sudo.

$ curl -fsSL https://claude.ai/install.sh | sudo bash
command not found: claude

The installer's bin folder is not in your PATH. Open a new terminal window — it usually picks up the PATH change automatically. If not, add the install path manually.

Browser did not open for auth

Run the login command manually.

$ claude auth login

You Are Ready

  • ✅Claude Code is installed globally on your machine.
  • ✅You are authenticated with your Claude account.
  • ✅You have run your first session and created a file.
  • →Next up: how Claude Code actually works under the hood — reading files, running tools, and managing context.

What's Next

Claude Code is installed and running. Next: understand what's actually happening under the hood when you send it a task.