How to install Claude Code and run your first session

Before you start

You need a terminal, a project folder and an account that includes Claude Code. Any code folder works for a first session. With no project yet, Anthropic's terminal guide says that's fine too, because Claude can help you start one. The same guide shows how to open a terminal if you have never used one.

The account is the step that catches people out. The setup page says Claude Code needs a Pro, Max, Ultra, Team or Enterprise plan, a Claude Console account, or access through Amazon Bedrock, Google Cloud's Agent Platform or Microsoft Foundry. Free claude.ai accounts are not on that list.

The figures below are the minimums. On Linux, the page lists Ubuntu 20.04, Debian 10 and Alpine Linux 3.19 or newer, and every install needs an internet connection.

Install Claude Code and start a session

Anthropic marks the native installer as recommended, so it is the one used here. Copy only the block that matches your system, paste it into the terminal and press Enter.

The installer shows no progress while it downloads. Leave the window open until it reports that Claude Code installed successfully.

# macOS, Linux, WSL
curl -fsSL https://claude.ai/install.sh | bash

# Windows PowerShell
irm https://claude.ai/install.ps1 | iex

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

1. Open a terminal. On macOS press Cmd + Space, type Terminal and press Enter. On Linux press Ctrl + Alt + T. On Windows press Win + X and pick Windows PowerShell or Terminal.
2. Paste the install command for your system and press Enter. Wait for the message that the install finished.
3. Open a new terminal window and run claude --version. A working install prints a version number followed by "(Claude Code)", such as 2.1.211 (Claude Code).
4. Go to a project folder with cd /path/to/your/project, replacing the path with your own, then run claude.
5. Log in when Claude Code asks. A browser window opens, you sign in with your Claude account, and the credentials are stored, so you do not log in again next time.
6. Type a first question, such as what does this project do?. Claude reads the files it needs, so you paste nothing in.
7. Ask for one small change, such as add a hello world function to the main file. Claude Code finds the file and shows the change. If it asks before making it, choose Yes to approve.
8. Leave with /exit, or press Ctrl + D twice on an empty prompt.

Which install method to pick

Pick the native installer unless a package manager is how you already install your tools. A native install updates itself in the background. Homebrew, WinGet, apt, dnf and apk installs do not do that by default, so you upgrade them yourself.

Homebrew picks the channel by cask name. claude-code follows the stable channel. Anthropic says that channel typically runs about a week behind and skips releases with major regressions. claude-code@latest gets each version as soon as it ships.

The npm route, npm install -g @anthropic-ai/claude-code, installs the same native binary. It asks for Node.js 22 or later, although an older version only prints an EBADENGINE warning and the install still completes. Never put sudo in front of it. Claude Code runs npm without sudo when it updates itself, so an install that needed sudo cannot update on its own. If npm --version starts with 12, read the FAQ below before you install, because Anthropic documents a separate fix for that version.

On a native install, claude update applies an update right away. claude doctor prints read-only diagnostics without starting a session, including install health and settings errors.

The commands you will use in your first hour

After login, the prompt appears with the version, the current model and the working directory above it. You can't click anything in the terminal, so move with the arrow keys. Press Esc to interrupt Claude while it works. Press Shift+Tab to switch the permission mode, which sets what Claude may do without asking you first. Lesson 2 is about that.

Typing / lists the commands and skills available to you, and Tab completes a command. The table has the rest of what the quickstart calls day-to-day use.

How Claude Code's creator runs his own setup

Boris Cherny created Claude Code and works on Claude at Anthropic. He shared his setup on X at the start of January 2026 and called it "surprisingly vanilla". Claude Code works well out of the box, he wrote, so he changes little. For a fresh install, that means the defaults from this lesson are a fine place to stay while you learn.

His tenth tip in the same thread is about approvals. He doesn't use --dangerously-skip-permissions. He runs /permissions to pre-allow common bash commands he knows are safe, and keeps most of those rules in .claude/settings.json, checked into git and shared with his team. When your sessions keep asking you to approve the same safe command, that dialog is where you allow it once.

Screenshots of X's own embeds of the posts, taken on 5 November 2026, with the time in UTC. X cuts the first post short with Show more. Select a screenshot to open the post on X.

Common mistakes

The most common failed install is a finished install that claude can't find. The installer puts the program in ~/.local/bin on macOS and Linux, or in %USERPROFILE%\.local\bin on Windows, and that folder has to be in your PATH. When the installer spots the problem, it says so under "Setup notes" and prints the fix, but it does not change your PATH itself. Anthropic's installation troubleshooting page has the full steps.

Run the pair of commands for your shell, then open a new terminal window. A window that was already open keeps its old PATH.

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

# Linux with Bash
echo 'export PATH="$HOME/.local/bin:$PATH"' >> ~/.bashrc
source ~/.bashrc

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

• Mixing up the Windows shells. 'irm' is not recognized means you are in CMD, so open PowerShell or use the CMD command. The token '&&' is not a valid statement separator means you ran the CMD command in PowerShell. A prompt that starts with PS is PowerShell.
• Running the macOS and Linux command on Windows. In PowerShell, curl is an alias for another command and rejects the -fsSL flags. Use the PowerShell command instead.
• Getting a web page where the script should be. syntax error near unexpected token '<' means the address returned HTML. If that page says "App unavailable in region", Claude Code is not offered in your country. Otherwise run the command again, or install with Homebrew.
• Leaving an old ANTHROPIC_API_KEY in your shell profile. Anthropic lists a stale key from a previous job or project as a cause of a disabled-organization error, because the key overrides your subscription.
• Following an older tutorial. Some in the search results still give Node.js 18 as the minimum, or start with sudo npm install -g. The setup page asks for Node.js on the npm route only, warns against sudo and lists the native installer first.
• Giving up when the browser does not open at login. Press c to copy the login address and paste it into a browser. If a login fails for no clear reason, /logout and then claude starts it clean.

Try it yourself

• Run claude --version and claude doctor in a plain terminal. Both should finish without an error.
• Open Claude Code in a project and ask the quickstart's three questions: what does this project do, what technologies does it use, and where is the main entry point.
• Ask for a one-line change in a scratch file. If Claude asks first, read the proposed edit before you approve it. Then press Esc during the next request to see that you can interrupt.
• Exit, run claude -c in the same folder and check that your earlier conversation is back.

Next: plan mode

Claude Code is installed, and it has made its first edit. Whether it asked first depends on the session's permission mode. Lesson 2 explains the modes and shows how to make Claude plan first and change nothing until you agree.

Two Mindket posts fit while you settle in. The CLAUDE.md guide covers the file of standing instructions for a project. Adding an MCP server to Claude Code covers connecting it to outside tools.

Frequently asked questions

Sources

1. Claude Code docs: Quickstart (read November 4, 2026)https://code.claude.com/docs/en/quickstart
2. Claude Code docs: Advanced setup (read November 4, 2026)https://code.claude.com/docs/en/setup
3. Claude Code docs: Terminal guide for new users (read November 4, 2026)https://code.claude.com/docs/en/terminal-guide
4. Claude Code docs: Troubleshoot installation and login (read November 4, 2026)https://code.claude.com/docs/en/troubleshoot-install
5. Boris Cherny on X: his Claude Code setup, 2 January 2026 (read November 5, 2026)https://x.com/bcherny/status/2007179832300581177
6. Boris Cherny on X: tip 10, permissions, 2 January 2026 (read November 5, 2026)https://x.com/bcherny/status/2007179854077407667