> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/instructkr/claude-code/llms.txt
> Use this file to discover all available pages before exploring further.

# Installation

> System requirements, platform-specific setup, authentication, upgrading, and uninstalling Claude Code.

## Requirements

| Requirement    | Minimum version           |
| -------------- | ------------------------- |
| Node.js        | 18.0.0                    |
| npm            | Included with Node.js 18+ |
| Bun (optional) | Any recent stable release |

Claude Code is distributed as an npm package. You do not need Bun to install or run the pre-built binary — Bun is only required if you are building from source.

## Install

```bash theme={null}
npm install -g @anthropic-ai/claude-code
```

After installation, verify it is available:

```bash theme={null}
claude --version
```

## Platform notes

<Tabs>
  <Tab title="macOS">
    Claude Code stores OAuth credentials in the **macOS Keychain**. No extra configuration is needed — the keychain integration is automatic.

    Two keychain entries are prefetched at startup to reduce authentication latency:

    * The OAuth token for your Anthropic account
    * A legacy API key slot (used when `ANTHROPIC_API_KEY` is set)

    If you see a Keychain permission dialog on first run, click **Allow**. This grants Claude Code access to store and retrieve your credentials securely.

    <Note>
      If you are on an Apple Silicon Mac and see a crash on startup, make sure you are running a native arm64 build of Node.js, not an x86\_64 build under Rosetta.
    </Note>
  </Tab>

  <Tab title="Linux">
    On Linux, credentials are stored in a local configuration file rather than a system keychain. The file is created at:

    ```
    ~/.config/claude-code/credentials.json
    ```

    Protect this file with appropriate permissions:

    ```bash theme={null}
    chmod 600 ~/.config/claude-code/credentials.json
    ```

    <Warning>
      Do not commit this file to version control or share it. It contains your OAuth token.
    </Warning>

    Make sure `ripgrep` (`rg`) is installed for the best search performance. Claude Code falls back to slower alternatives if `rg` is not available.

    ```bash theme={null}
    # Debian/Ubuntu
    apt install ripgrep

    # Fedora
    dnf install ripgrep

    # Arch
    pacman -S ripgrep
    ```
  </Tab>

  <Tab title="Windows">
    Claude Code runs on Windows via **WSL 2** (Windows Subsystem for Linux). A native Windows binary is not currently available.

    <Steps>
      <Step title="Enable WSL 2">
        ```powershell theme={null}
        wsl --install
        ```

        Restart your machine if prompted.
      </Step>

      <Step title="Open a WSL terminal">
        Launch your WSL distribution (Ubuntu is the default) from the Start menu or by running `wsl` in PowerShell.
      </Step>

      <Step title="Install Node.js inside WSL">
        ```bash theme={null}
        curl -fsSL https://deb.nodesource.com/setup_20.x | sudo -E bash -
        sudo apt install -y nodejs
        ```
      </Step>

      <Step title="Install Claude Code">
        ```bash theme={null}
        npm install -g @anthropic-ai/claude-code
        ```
      </Step>
    </Steps>

    <Info>
      Run Claude Code from within a WSL terminal, not from a Windows Command Prompt or PowerShell window. File paths, shell commands, and git operations all run in the Linux environment.
    </Info>
  </Tab>
</Tabs>

## Authentication setup

Claude Code uses OAuth 2.0 to authenticate with your Anthropic account.

**First-time setup:**

1. Run `claude` to open the REPL.
2. Type `/login` at the prompt.
3. Your browser opens the Anthropic authorization page.
4. Approve access and return to the terminal.

Claude Code stores the resulting token securely (Keychain on macOS, a local file on Linux) and refreshes it automatically. You do not need to repeat this process unless you explicitly log out or revoke access.

**API key alternative:**

If you prefer not to use OAuth, set the `ANTHROPIC_API_KEY` environment variable before launching Claude Code:

```bash theme={null}
export ANTHROPIC_API_KEY="sk-ant-..."
claude
```

When an API key is present, the `/login` command switches between accounts rather than initiating a new OAuth flow.

**Logging out:**

```
/logout
```

This revokes the stored token and clears the local credential cache.

## Upgrading

```bash theme={null}
npm update -g @anthropic-ai/claude-code
```

Claude Code also has a built-in auto-updater that runs in the background. If a new version is available, you will see a notification in the REPL. You can disable auto-updates in your settings if you prefer to control upgrades manually.

## Uninstalling

```bash theme={null}
npm uninstall -g @anthropic-ai/claude-code
```

To also remove stored credentials and configuration:

<Tabs>
  <Tab title="macOS">
    ```bash theme={null}
    # Remove configuration directory
    rm -rf ~/Library/Application\ Support/claude-code

    # Remove Keychain entries (optional)
    security delete-generic-password -s "claude-code" 2>/dev/null || true
    ```
  </Tab>

  <Tab title="Linux">
    ```bash theme={null}
    rm -rf ~/.config/claude-code
    ```
  </Tab>
</Tabs>

## Verifying the installation

```bash theme={null}
claude --version
```

If the command is not found after a global npm install, your npm global `bin` directory may not be on your `PATH`. Find it with:

```bash theme={null}
npm bin -g
```

Then add that directory to your shell's `PATH` in `~/.bashrc`, `~/.zshrc`, or equivalent:

```bash theme={null}
export PATH="$(npm bin -g):$PATH"
```

<Tip>
  Run `/doctor` inside the Claude Code REPL for a comprehensive health check that covers authentication, runtime versions, network access, and configuration.
</Tip>