Getting started with Claude Code, from install to your first hour

Two things trip people up on a first install of Claude Code: which install method to pick, and what to check once it is in.

The short answer: pick the install method by whether it auto-updates. Only the native installer and npm update themselves; Homebrew, WinGet and the Linux package managers are manual. Then verify with claude --version and claude doctor before starting your first session.

Everything below comes from the official documentation as fetched on 2026-10-14. For what Claude Code is, see What Claude Code is; this page goes in the order you actually type things.

Requirements and the plans that include it

Item	Requirement
OS	macOS 13.0+, Windows 10 1809+ or Windows Server 2019+, Ubuntu 20.04+, Debian 10+, Alpine Linux 3.19+
Hardware	4 GB+ RAM, x64 or ARM64
Shell	Bash, Zsh, PowerShell or CMD
Network	An internet connection is required

Choose an install method by its update behavior

This is the first fork in the road. Only the native installer and npm update themselves.

Method	Command	Auto-updates
Native (recommended)	curl -fsSL https://claude.ai/install.sh | bash	Yes
Homebrew	brew install --cask claude-code	No
WinGet	winget install Anthropic.ClaudeCode	No
apt / dnf / apk	Register the repository, then install	No
npm	npm install -g @anthropic-ai/claude-code	Yes

On macOS, Linux and WSL the native install is one line:

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

On Windows the command depends on your shell. Your prompt shows PS C:\ in PowerShell and C:\ without the PS in CMD.

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

curl -fsSL https://claude.ai/install.cmd -o install.cmd && install.cmd && del install.cmd

The install command shows no progress while it downloads. When it finishes, open a new terminal window before checking.

The npm package needs Node.js 22 or later. Do not use sudo npm install -g — the documentation warns it leads to permission issues and security risks.

Verify, then start your first session

claude --version

A working installation prints a version number such as 2.1.211 (Claude Code). If you get command not found, the install directory is not on your PATH yet.

For a fuller check, claude doctor prints read-only installation and settings diagnostics without starting a session: install health, settings-file validation errors, and warnings with suggested fixes. It also reports the result of the most recent update attempt.

claude doctor

Then start it in the project you want to work in:

cd /path/to/your/project
claude

The first run prompts you to log in through your browser. If you have set ANTHROPIC_API_KEY and you approve the key when Claude Code asks whether to use it, the login prompt is skipped. Once you are logged in, the credentials are stored.

What to decide on Windows

Windows gives you native or WSL, and the difference that matters most is whether sandboxing is available.

Option	Sandboxing	When to use
Native Windows	Not supported	Windows-native projects and tools
WSL 2	Supported	Linux toolchains, or sandboxed command execution
WSL 1	Not supported	If WSL 2 is unavailable

On native Windows, Git for Windows is optional but worth having: it provides Git Bash, which backs the Bash tool. Without it, Claude Code runs shell commands through the PowerShell tool. If Git Bash cannot be found, point at it in settings:

{
  "env": {
    "CLAUDE_CODE_GIT_BASH_PATH": "C:\\Program Files\\Git\\bin\\bash.exe"
  }
}

The first hour

Once a session is open, work through these in order.

1. Check the permission mode. It shows in the status bar. With v2.1.283 or later, terminal and VS Code sessions start in auto on every plan. Shift+Tab cycles modes at any time. The six modes are compared in Claude Code permission modes
2. Have it explain the project. Just ask what does this project do? — Claude reads the files it needs, so you don't add context by hand
3. Create a CLAUDE.md. /init scaffolds one for the project. For what to put in it, see How to write CLAUDE.md
4. Send one small change. Something like add a hello world function to the main file, to see the approval flow once
5. Write a single deny rule. Before widening the automation, put what must not be touched into permissions.deny in .claude/settings.json — see Design permissions in Claude Code's settings.json
6. Look at your usage. /usage shows how much of your plan you are consuming; Check Claude Code usage and cost covers the rest

The commands worth memorizing:

Command	What it does
claude	Start interactive mode
claude "task"	Start with an initial prompt
claude -p "query"	Run one query, then exit
claude -c	Continue the most recent conversation in this directory
claude -r	Resume a previous conversation
/help	Show available commands
/clear	Clear conversation history
/login	Switch accounts or re-authenticate

Summary

• Requirements: macOS 13.0+, Windows 10 1809+, Ubuntu 20.04+ and similar, with 4 GB+ RAM
• The free claude.ai plan does not include Claude Code; you need Pro, Max, Team, Enterprise, Console or a cloud provider
• Pick the install method by auto-update behavior: native and npm update themselves, Homebrew, WinGet, apt, dnf and apk do not
• Verify with claude --version, and read claude doctor when something is off
• On Windows, sandboxing means WSL 2; native Windows and WSL 1 do not support it
• In the first hour: check the permission mode, run /init, send one small change, then write a deny rule