Claude Code Setup

Overview

Claude Code is Anthropic's official command-line AI coding tool. This guide covers Windows, Mac, and Linux.

Install Node.js and Git first — see Node.js and Git Setup. For one-click channel management, see CC-Switch Setup.

Install Claude Code

Install

All three platforms share the same npm command:

npm install -g @anthropic-ai/claude-code

Verify:

claude -v

A version number means the install succeeded.

Common issues

Q: permission denied / EACCES (Mac / Linux)

Don't use sudo. Move the npm global prefix to your home directory:

mkdir ~/.npm-global
npm config set prefix '~/.npm-global'
echo 'export PATH=~/.npm-global/bin:$PATH' >> ~/.bashrc   # zsh users: ~/.zshrc
source ~/.bashrc

Q: permission denied (Windows)

Run PowerShell as Administrator:

npm config set prefix "$env:APPDATA\npm"
Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser

Q: command not found: claude

The npm global bin directory is not on PATH. Run npm config get prefix to see the location, then append its /bin directory to the system PATH.

Configure the API Key

CC-Switch (recommended)

A GUI tool with one-click channel switching that writes the Claude Code plugin config automatically — no manual environment variables.

See CC-Switch Setup.

Manual environment variables

Windows

Open PowerShell as Administrator and run:

setx ANTHROPIC_BASE_URL "your-api-url"
setx ANTHROPIC_AUTH_TOKEN "your-key"

Close and reopen the terminal, then verify:

# PowerShell
echo $env:ANTHROPIC_BASE_URL
echo $env:ANTHROPIC_AUTH_TOKEN

# cmd
echo %ANTHROPIC_BASE_URL%
echo %ANTHROPIC_AUTH_TOKEN%

Mac / Linux

Edit your shell config (zsh → ~/.zshrc, bash → ~/.bashrc, macOS bash → ~/.bash_profile):

vim ~/.zshrc

Append:

export ANTHROPIC_BASE_URL="your-api-url"
export ANTHROPIC_AUTH_TOKEN="your-key"

Save, reload, and verify:

source ~/.zshrc
echo $ANTHROPIC_BASE_URL
echo $ANTHROPIC_AUTH_TOKEN

Get Started

Open a terminal in any project directory (on Windows, right-click → Open in Terminal or Git Bash Here) and run claude:

cd your/project
claude

The first launch prompts for theme, directory trust, and login method (skipped if you enabled "skip first-run prompts" in CC-Switch).

Once the > prompt appears, describe what you want in plain English (or Chinese), for example:

Create a hello.py in the current directory that prints "Hello World"

Handy shortcuts:

• /help — list all commands
• /clear — wipe the current conversation
• /exit or press Ctrl + C twice — exit