Getting Started

What is Claude Code?

Claude Code is an AI coding assistant that lives in your terminal — the text-based window where developers type commands. Instead of clicking buttons in an app, you type what you want in plain English, and Claude reads your code, suggests fixes, writes new features, runs tests, and even manages files — all by understanding your project directly on your machine.

Before you can use any slash command or build a workflow, you need Claude Code running on your machine. This module walks you through installation, authentication, picking the right terminal and IDE setup, and running your very first session.

Prerequisites

Claude Code runs on macOS 13+, Ubuntu 20.04+ (and other modern Linux distros), and Windows 10 1809+ (native or WSL). You need at least 4 GB of RAM — 8 GB is recommended for comfortable use. An active internet connection is required at all times.

You also need a paid Anthropic subscription. Claude Code is available on Claude Pro, Max, Team, and Enterprise plans. The free Claude.ai plan does not include Claude Code access. Alternatively, you can use an API key from the Anthropic Console or connect through Amazon Bedrock, Google Vertex AI, or Microsoft Foundry.

On Windows, Git for Windows must be installed separately before Claude Code will work.

Installing the CLI

The recommended way to install Claude Code is the native installer. It auto-updates in the background so you always have the latest version.

On macOS or Linux (including WSL):

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

On Windows via PowerShell:

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

On Windows via CMD:

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

There are alternative installation methods, but they require manual updates. Homebrew: brew install --cask claude-code. WinGet: winget install Anthropic.ClaudeCode. The npm method (npm install -g @anthropic-ai/claude-code) still works but is deprecated — it will eventually stop receiving updates.

After installation, verify it worked:

claude --version

You can control the update channel through /config — choose between latest (newest features) and stable (tested releases).

Authentication

When you run claude for the first time, it automatically opens your browser for OAuth authentication. Sign in with your Anthropic account and you’re ready to go.

If you’re using an API key instead, set the environment variable before launching:

export ANTHROPIC_API_KEY=sk-ant-...
claude

For enterprise or cloud provider setups, use the corresponding environment variables:

• Amazon Bedrock: CLAUDE_CODE_USE_BEDROCK=1
• Google Vertex AI: CLAUDE_CODE_USE_VERTEX=1
• Microsoft Foundry: CLAUDE_CODE_USE_FOUNDRY=1

Your credentials are stored securely — in the macOS Keychain on Mac, or in ~/.claude/.credentials.json (mode 0600) on Linux and Windows.

To switch accounts or re-authenticate at any time, use /logout.

Your Terminal: Warp Recommended

Claude Code works in any terminal — Terminal.app, iTerm2, Windows Terminal, Alacritty, Kitty, Ghostty, and more. But for the best experience, we recommend Warp.

Warp has an official Claude Code plugin that provides native desktop notifications when Claude completes a task, needs your input, or requests permissions. This is especially useful for long-running operations where you switch to another window.

To set up the Warp plugin, run these commands inside Claude Code after installation:

/plugin marketplace add warpdotdev/claude-code-warp
/plugin install warp@claude-code-warp

Restart Claude Code after installation to activate the plugin. You’ll get native OS notifications for task completions, idle states, and permission requests — no more checking back manually.

If you prefer a different terminal, Claude Code also has a built-in /terminal-setup command that auto-configures notification support for terminals like Kitty, Ghostty, and Alacritty.

IDE Extensions

Claude Code started as a CLI tool, but it now has official extensions for major editors. You can use both — the CLI for heavy terminal work and the extension for in-editor convenience.

VS Code is the most mature integration. Install it from the VS Code Marketplace or run code --install-extension Anthropic.claude-code. It gives you a native graphical interface, visual diff review, file references, conversation history, and the ability to run multiple conversations in tabs.

JetBrains has an official plugin in beta, available in the JetBrains Marketplace for IntelliJ IDEA, WebStorm, PyCharm, and other JetBrains IDEs. It orchestrates the CLI with the IDE’s diff viewer for a seamless experience.

Both Cursor and Windsurf (VS Code forks) also support Claude Code extensions.

Beyond IDE extensions, there’s also a Desktop App for macOS and Windows that provides visual diffs, live app preview, and autonomous background agents — no terminal needed. And Claude Code on the Web (claude.ai/code) is a research preview that runs on cloud VMs, so you can work from any browser without any local setup.

Your First Session

Navigate to any project directory and launch Claude Code:

cd my-project
claude

You’ll see a welcome message and a prompt. Just type what you want Claude to do in plain English:

What files are in this project and what does it do?

Claude will read your files, analyze the structure, and give you a summary. From here, you can ask it to make changes, fix bugs, run tests, or explain code. When Claude needs to perform actions like editing files or running commands, it will ask for your permission first.

That’s it — you’re ready. Head to the next module to learn the slash commands that make Claude Code truly powerful.