Setting Up Claude Code
1. Installing Claude Code CLI
The Claude Code CLI is a command-line tool that enables developers to interact with the Claude AI assistant directly from their terminal. It supports various operating systems and can be installed through different methods depending on your environment.
| Installation Method | Description | Command |
|---|---|---|
| Using npm | Installs the latest stable version via Node Package Manager | npm install -g claude-code-cli |
| Using Homebrew (macOS) | Installs via Homebrew package manager on macOS | brew tap anthropic/claude-code && brew install claude-code |
| Manual Download | Download pre-built binaries for Linux, macOS, or Windows | curl -L https://github.com/anthropic/claude-code-cli/releases/latest/download/claude-code-cli-$(uname -s)-$(uname -m).tar.gz | tar xz |
Note: Ensure that Node.js (v16 or higher) is installed if using the npm method.
2. Authenticating Claude Code with an API Key
Authenticate your Claude Code environment using an API key to enable access to AI-powered features and code assistance.
| Step | Description | Action |
|---|---|---|
| 1. Obtain API Key | Generate an API key from the Claude dashboard. | Visit https://claude.ai/api-keys and create a new key. |
| 2. Set Environment Variable | Store the key securely in your environment. |
export CLAUDE_API_KEY="sk-ant-api03-...-gpt-4"
|
| 3. Configure IDE | Integrate the key into your development environment. | Add to .env or IDE settings for Claude extension. |
Note: Keep your API key secure and never commit it to version control.
Warning: Using a compromised key may lead to unauthorized usage and billing issues.
3. Starting Claude Code Sessions
| Command | Description | Notes |
|---|---|---|
| claude code start | Initiates a new Claude Code session | Starts an interactive development environment with AI assistance |
| claude code session list | Lists all active Claude Code sessions | Shows session IDs and status for each ongoing session |
| claude code session stop <session-id> | Stops a specific Claude Code session | Terminates the specified session by ID |
4. Configuring Claude Code Permissions
| Permission | Description | Required | Notes |
|---|---|---|---|
| access.code | Access to view and edit code in Claude Code | Yes | Allows reading and modifying files within the project |
| access.models | Access to Claude's AI models | Yes | Required for generating code suggestions and responses |
| access.filesystem | Access to file system operations | Yes | Needed for navigating and managing project files |
| access.network | Network access for API calls to Claude services | Yes | Essential for real-time AI assistance and model interactions |
| access.settings | Access to modify Claude Code settings | No | Optional, used for advanced configuration and preferences |
Example: Setting up Claude Code Permissions in VS Code
{
"claude.code.permissions": {
"access.code": true,
"access.models": true,
"access.filesystem": true,
"access.network": true,
"access.settings": false
}
}
Note: Ensure that the
access.network permission is enabled to allow Claude Code to communicate with the AI models.
Warning: Disabling
access.code will prevent Claude Code from making any code changes or suggestions.
5. Using Claude Code in Headless Mode
| Option | Values | Notes |
|---|---|---|
| claude-code.headless | true |
Enables headless mode for Claude Code |
| claude-code.port | 8080 |
Port to run the Claude Code server on |
| claude-code.api-key | string |
API key for Claude Code access |
Example: Running Claude Code in Headless Mode
claude-code --headless --port 8080 --api-key "sk-ant-api03-..."
Note: Headless mode is useful for CI/CD pipelines or server environments where a GUI is not available.
Warning: Ensure that the API key is securely stored and not exposed in logs or version control.
Headless Mode Configuration
- Set
claude-code.headlesstotrueto enable headless mode. - Specify the port using
claude-code.port. - Provide your API key via
claude-code.api-key.
6. Configuring Claude Code Model Selection
| Model | Description | Capabilities | Notes |
|---|---|---|---|
| claude-3-5-sonnet | Latest Claude 3.5 model with improved reasoning and code generation |
|
Recommended for most use cases NEW |
| claude-3-opus | Most capable Claude model with strong reasoning and code understanding |
|
Best for complex AI-assisted development tasks |
| claude-3-sonnet | Balance of speed and capability for general AI-assisted development |
|
Good for real-time code assistance |
| claude-3-haiku | Fastest Claude model for quick code tasks |
|
Best for rapid prototyping or simple code tasks |
Example: Claude Code Model Configuration
{
"claude.code.model": "claude-3-5-sonnet",
"claude.code.temperature": 0.7,
"claude.code.maxTokens": 1024
}
Note: The model selection affects response time and code quality. Higher capability models like
claude-3-opus may take longer to respond but provide better code understanding.
Warning: Using
claude-3-haiku for complex code refactoring may result in incomplete or incorrect suggestions.
7. Using Claude Code Slash Commands
| Command | Description | Usage |
|---|---|---|
| /help | Displays available slash commands and their descriptions | /help |
| /explain | Explains selected code or a specific line of code | /explain <code> |
| /fix | Fixes issues in selected code or suggests improvements | /fix <code> |
| /test | Generates unit tests for selected code or a function | /test <code> |
| /doc | Generates documentation for selected code or function | /doc <code> |
| /translate | Translates selected code to another programming language | /translate <language> |
Example: Using /explain
// Select the following code and type /explain
const calculateTotal = (items) => {
return items.reduce((sum, item) => sum + item.price, 0);
};Example: Using /fix
// Select the following code and type /fix
const processArray = (arr) => {
const result = [];
for (let i = 0; i <= arr.length; i++) {
result.push(arr[i] * 2);
}
return result;
};8. Resuming Previous Claude Code Sessions
| Session ID | Status | Last Activity | Action |
|---|---|---|---|
| claude-code-2025-04-01 | Active | 2025-04-01 14:30 | |
| claude-code-2025-03-28 | Paused | 2025-03-28 10:15 | |
| claude-code-2025-03-20 | Completed | 2025-03-20 16:45 |
Note: Sessions are automatically saved every 15 minutes during active use.
Warning: Sessions older than 30 days will be automatically deleted.
9. Configuring Claude Code Output Styles
| Setting | Description | Values | Notes |
|---|---|---|---|
| claude.code.output.style | Controls the output style of Claude Code completions | inline, block |
Default is inline |
| claude.code.output.language | Sets the language for Claude Code output | javascript, python, java, go, typescript |
Applies to block output style |
| claude.code.output.wrap | Enables or disables code wrapping in output | true, false |
Default is false |
Example: Setting Output Style to Block
{
"claude.code.output.style": "block",
"claude.code.output.language": "javascript"
}
Note: The
block output style wraps code in a proper code block with syntax highlighting support.
10. Integrating Claude Code with Terminal Workflows
Example: Setting up Claude Code in Terminal
export CLAUDE_API_KEY="your-api-key-here"
export CLAUDE_CODE_PATH="/path/to/claude-code"
# Run Claude Code in terminal
cd $CLAUDE_CODE_PATH
npm run start
| Workflow Step | Description | Command |
|---|---|---|
| 1. Initialize Claude Code | Set up the Claude Code environment in your terminal | npm init -y |
| 2. Install Dependencies | Install required packages for Claude Code integration | npm install claude-code |
| 3. Configure API Key | Set the Claude API key in environment variables | export CLAUDE_API_KEY="your-key" |
| 4. Start Terminal Session | Launch Claude Code in terminal mode | npm run start |
Note: Ensure that your terminal supports ANSI color codes for full integration.