> ## Documentation Index
> Fetch the complete documentation index at: https://docs.byterouter.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Using ByteRouter with Claude Code

> Detailed guide on how to configure and use ByteRouter API service in Claude Code CLI, enabling you to call various AI models directly from the terminal for coding assistance.

## Prerequisites

Claude Code is a command-line AI programming assistant from Anthropic that supports direct conversation with AI, code generation, debugging, and more in your terminal.
By integrating ByteRouter, you can access multiple AI models including GPT, Claude, and Gemini directly within Claude Code.

Before getting started, ensure you have:

1. **ByteRouter API Key**
   Sign in to [ByteRouter Console](https://byterouter.ai/keys) to get your API key

<Note>**Tip:** If you don't have a ByteRouter account yet, register at [ByteRouter](https://byterouter.ai) first and obtain your API key.</Note>

## Step 1: Install Claude Code

Choose one of the following installation methods:

<Tabs>
  <Tab title="macOS / Linux (Recommended)">
    Install using the official script:

    ```bash theme={null} theme={null}
    curl -fsSL https://claude.ai/install.sh | bash
    ```

    Or install via Homebrew:

    ```bash theme={null} theme={null}
    brew install --cask claude-code
    ```

    <Note>If you encounter permission issues, prepend `sudo` to the command.</Note>
  </Tab>

  <Tab title="Windows">
    **PowerShell:**

    ```powershell theme={null} theme={null}
    irm https://claude.ai/install.ps1 | iex
    ```

    **CMD:**

    ```cmd theme={null} theme={null}
    curl -fsSL https://claude.ai/install.cmd -o install.cmd && install.cmd && del install.cmd
    ```
  </Tab>

  <Tab title="NPM Installation">
    If you have Node.js 18 or later installed, you can install via npm:

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

    Works on all operating systems.
  </Tab>
</Tabs>

### Verify Installation

After installation, run the following command to confirm success:

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

If a version number (e.g., `1.x.x`) is displayed, the installation is successful.

## Step 2: Configure ByteRouter API

Three configuration methods are available. Choose the one that suits your workflow.

### Method 1: Edit settings.json (Recommended)

This is the most stable configuration method and works persistently after one-time setup.

**1. Find the configuration directory:**

* Windows: Press `Win + R`, type `%userprofile%\.claude`
* macOS: Press `Command + Shift + G`, type `~/.claude`
* Linux: Navigate to `~/.claude` directory

<Note>If the directory doesn't exist, run `claude` once in your terminal and press `Ctrl + C` to exit. The directory will be created automatically.</Note>

**2. Create or edit the `settings.json` file:**

```json theme={null} theme={null}
{
  "env": {
    "ANTHROPIC_BASE_URL": "https://byterouter.ai/v1",
    "ANTHROPIC_AUTH_TOKEN": "your_api_key_here",
    "ANTHROPIC_MODEL": "claude-sonnet-4.6"
  }
}
```

| Parameter              | Description                                                  |
| ---------------------- | ------------------------------------------------------------ |
| `ANTHROPIC_BASE_URL`   | ByteRouter API endpoint, fixed as `https://byterouter.ai/v1` |
| `ANTHROPIC_AUTH_TOKEN` | Your ByteRouter API key                                      |
| `ANTHROPIC_MODEL`      | Default model to use, choose from the list below             |

After saving, restart Claude Code for changes to take effect.

### Method 2: Permanent Environment Variables

Configure at the system level so all terminal windows automatically load the settings.

<Tabs>
  <Tab title="macOS (zsh)">
    ```bash theme={null} theme={null}
    echo 'export ANTHROPIC_BASE_URL="https://byterouter.ai/v1"' >> ~/.zshrc
    echo 'export ANTHROPIC_AUTH_TOKEN="your_api_key_here"' >> ~/.zshrc
    echo 'export ANTHROPIC_MODEL="claude-sonnet-4.6"' >> ~/.zshrc
    source ~/.zshrc
    ```
  </Tab>

  <Tab title="macOS / Linux (bash)">
    ```bash theme={null} theme={null}
    echo 'export ANTHROPIC_BASE_URL="https://byterouter.ai/v1"' >> ~/.bashrc
    echo 'export ANTHROPIC_AUTH_TOKEN="your_api_key_here"' >> ~/.bashrc
    echo 'export ANTHROPIC_MODEL="claude-sonnet-4.6"' >> ~/.bashrc
    source ~/.bashrc
    ```
  </Tab>

  <Tab title="Windows">
    **Method A: GUI Settings**

    1. Right-click "This PC" → "Properties" → "Advanced system settings" → "Environment Variables"
    2. Under "User variables", create new variables:
       * `ANTHROPIC_BASE_URL` = `https://byterouter.ai/v1`
       * `ANTHROPIC_AUTH_TOKEN` = `your_api_key_here`
       * `ANTHROPIC_MODEL` = `claude-sonnet-4.6`
    3. Restart your terminal window

    **Method B: PowerShell Command**

    ```powershell theme={null} theme={null}
    [System.Environment]::SetEnvironmentVariable('ANTHROPIC_BASE_URL', 'https://byterouter.ai/v1', 'User')
    [System.Environment]::SetEnvironmentVariable('ANTHROPIC_AUTH_TOKEN', 'your_api_key_here', 'User')
    [System.Environment]::SetEnvironmentVariable('ANTHROPIC_MODEL', 'claude-sonnet-4.6', 'User')
    ```
  </Tab>
</Tabs>

### Method 3: Temporary Environment Variables

Suitable for temporary testing. Configuration will be lost when you close the terminal.

<Tabs>
  <Tab title="macOS / Linux">
    ```bash theme={null} theme={null}
    export ANTHROPIC_AUTH_TOKEN="your_api_key_here"
    export ANTHROPIC_MODEL="claude-sonnet-4.6"
    export ANTHROPIC_BASE_URL="https://byterouter.ai/v1"
    claude
    ```
  </Tab>

  <Tab title="Windows (PowerShell)">
    ```powershell theme={null} theme={null}
    $env:ANTHROPIC_AUTH_TOKEN="your_api_key_here"
    $env:ANTHROPIC_MODEL="claude-sonnet-4.6"
    $env:ANTHROPIC_BASE_URL="https://byterouter.ai/v1"
    claude
    ```
  </Tab>

  <Tab title="Windows (CMD)">
    ```cmd theme={null} theme={null}
    set ANTHROPIC_AUTH_TOKEN=your_api_key_here
    set ANTHROPIC_MODEL=claude-sonnet-4.6
    set ANTHROPIC_BASE_URL=https://byterouter.ai/v1
    claude
    ```
  </Tab>
</Tabs>

<Warning>Temporary environment variables only work in the current terminal window. You'll need to reconfigure them after opening a new terminal or restarting.</Warning>

## Step 3: Get Started

### Verify Configuration

Start Claude Code and send a simple message to confirm configuration:

```bash theme={null} theme={null}
claude "Hello"
```

If you receive an AI response, the configuration is successful. If you encounter errors, refer to the troubleshooting section below.

### Usage Modes

Claude Code offers two interaction modes:

* **Interactive Mode**: Run `claude` to enter continuous conversation, ideal for complex tasks
* **Single Command**: Run `claude "your question"` to get a one-time response and exit, perfect for quick queries

### Supported Models

ByteRouter supports various AI models that you can switch between based on your needs. See the [Getting Started](/quickstart) page for the complete model list.

#### Common Model Examples

| Model Name          | Characteristics                |
| ------------------- | ------------------------------ |
| `claude-sonnet-4.6` | Balanced performance and speed |
| `claude-opus-4.5`   | Strongest overall capability   |
| `gpt-4.1`           | Efficient GPT model            |
| `gemini-2.0`        | Google's advanced model        |

### Common Commands

Here are frequently used commands and shortcuts in Claude Code:

| Command             | Description                      |
| ------------------- | -------------------------------- |
| `claude`            | Enter interactive mode           |
| `claude "question"` | Ask a single question            |
| `claude --version`  | Check version number             |
| `/model`            | Switch model in interactive mode |
| `/help`             | View help information            |
| `Ctrl + C`          | Exit interactive mode            |

## Troubleshooting

### Q1: Login selection screen still appears after configuration?

If "Select login method" is displayed, the configuration hasn't taken effect.

**Troubleshooting steps:**

1. **Using settings.json method**: Verify the file path is correct
   * Windows: `C:\Users\<username>\.claude\settings.json`
   * macOS / Linux: `~/.claude/settings.json`
2. **Using environment variables**: Ensure you started Claude Code **in the same terminal window** where you set the variables
3. **Check JSON format**: Make sure brackets, commas, and quotes are correct (don't use Chinese quotes)

### Q2: Authentication errors?

| Error Message      | Meaning                  | Solution                                                                              |
| ------------------ | ------------------------ | ------------------------------------------------------------------------------------- |
| `401 Unauthorized` | Invalid API key          | Check your key is correct, verify in [ByteRouter Console](https://byterouter.ai/keys) |
| `403 Forbidden`    | Insufficient permissions | Confirm your API key isn't expired or disabled                                        |

Ensure `ANTHROPIC_BASE_URL` is set to `https://byterouter.ai/v1`.

### Q3: "Unable to connect" error?

This means Claude Code cannot connect to the API service.

1. Check your network connection
2. Verify `ANTHROPIC_BASE_URL` is configured correctly
3. If using a proxy, ensure it allows access to `byterouter.ai`

### Q4: How to switch models?

Two options:

1. **In interactive mode**: Type `/model` command to switch
2. **Modify configuration**: Change the `ANTHROPIC_MODEL` field in `settings.json` or environment variables, then restart Claude Code

### Q5: Slow responses?

1. Try switching to a faster model
2. Shorten your questions to reduce context length
3. Check your local network status

## Support & Help

If you encounter any issues:

* 📧 Technical Support: [br@byterouter.ai](mailto:br@byterouter.ai)

***

<Card title="Get Started with ByteRouter" icon="rocket" href="https://byterouter.ai">
  Register now and get your API key to start using multiple AI models in Claude Code!
</Card>