How to Use Claude Code CLI: Complete Step by Step Guide
By Braincuber Team
Published on April 21, 2026
Claude Code CLI allows developers to integrate AI-powered coding assistance into everyday terminal workflows. This comprehensive guide walks you through installation, authentication, core commands, and real-world workflows for analyzing and improving codebases.
What You'll Learn:
- What Claude Code CLI is and why developers use it
- Installation methods for macOS, Linux, and Windows
- Core commands and CLI flags
- Real-world use cases for automation
- Security and privacy best practices
What Is Claude Code CLI?
Claude Code CLI is a command-line interface for interacting with Claude's AI coding capabilities directly from your local development environment. Built by Anthropic, Claude excels at tasks involving language, reasoning, analysis, coding, and more.
Instead of opening a browser or IDE plugin, developers can run commands like:
claude code analyze ./project
The CLI sends project context to Claude, which can then perform tasks such as:
- Analyzing codebases
- Generating code
- Refactoring existing code
- Producing documentation
- Creating unit tests
- Fixing code issues
Why Developers Use Claude Code CLI
Terminal-based workflows are preferred by developers because they work well with tools like Git, package managers, and CI/CD pipelines. This ecosystem is a good fit for Claude Code CLI.
Works with Existing Workflows
Integrates easily with Git repositories, local project directories, shell scripts, and automation pipelines.
Scriptable Automation
Include Claude commands inside automation scripts or CI pipelines for automated code analysis.
Faster Feedback
Get AI help quickly without leaving the console. No need to switch between IDE, browser, and documentation.
Terminal-First Environments
Fits naturally into VS Code terminal, SSH remote servers, and Docker containers.
Common Real-World Use Cases
Codebase Audits
Running automated analysis on an entire repository to identify security issues, detect code smells, and suggest architecture improvements.
Generating Documentation
Automatically generating README files or inline documentation for your codebase.
Pattern Enforcement
Ensuring coding standards such as consistent logging, type hints, and naming conventions across your project.
CI/CD Integration
Running automated AI audits during build pipelines to catch issues before deployment.
Installing Claude Code CLI
Before installing Claude Code CLI, you need a few basic tools installed on your system.
Prerequisites
| Requirement | Description |
|---|---|
| Node.js | v18 or later |
| npm or yarn | Package manager |
| Internet access | For API requests |
| Anthropic API key | From Anthropic console |
| Git | For Windows users |
Installation via npm
The CLI can be installed using npm. This installs the tool globally so it can be used from any directory.
npm install -g @anthropic-ai/claude-code
Installation via Homebrew
On macOS, you can also install using Homebrew:
brew install --cask claude-code
Native Installation (Recommended)
The recommended method is the native installation which works across platforms:
macOS / Linux / WSL
curl -fsSL https://claude.ai/install.sh | bash
Windows PowerShell
irm https://claude.ai/install.ps1 | iex
Verify the Installation
After installation, create a simple test project to verify everything works:
claude
This starts an interactive session with Claude. Type exit to quit when finished.
Core Claude Code CLI Commands
When you install Claude Code and type claude in your terminal, a set of built-in slash commands are available immediately. These are called core commands and work out of the box.
claude
Starts an interactive session with the initial prompt. Send your first message to begin.
claude -p "prompt"
Reads file content and answers your query. Useful when you want Claude to analyze a specific file without pointing it at your whole project.
claude -p "refactor hello.py"
claude -c -p "prompt"
Combines -c (continue) and -p (print) flags. Resumes the most recent session, sends a new prompt, then exits automatically.
claude -c -p "now check for type errors"
claude update
Updates Claude Code to the latest available version. Run this periodically to ensure you have the newest features and bug fixes.
claude agents
Lists all configured subagents, grouped by source. Subagents are specialized AI assistants that handle specific types of tasks.
Key CLI Flags
CLI flags are added to the claude command to change how it behaves. They go between claude and your prompt. You can combine multiple flags in one command.
--model
Sets the Claude model to be used for the session. You can use a short alias (sonnet or opus) or the full model name. Different models have different speeds and costs.
claude --model sonnet
Sends the prompt, prints the response, and exits immediately. Useful for scripting and automation.
claude --print "explain hello.py"
--output-format
Controls the output format. The default is plain text. Other options include JSON for programmatic use.
claude -p "review hello.py" --output-format text
claude auth logout
Logs you out from your Anthropic account.
claude auth logout
CLI vs. Web / IDE Workflows
Developers often want to know if CLI tools can take the role of web or IDE interfaces. Each approach offers different strengths:
| Approach | Best For |
|---|---|
| CLI Tools | Automation, scripting, CI/CD pipelines, batch processes |
| Web/IDE Tools | Interactive debugging, visual editing, faster experimentation |
Many developers combine both approaches: using CLI for automation and UI tools for exploration.
Pro Tip
Create automation scripts that use Claude Code CLI for repetitive tasks like code reviews, documentation generation, or test creation.
Security and Privacy Considerations
As AI tools interact with external APIs, it is important for developers to consider security implications.
Avoid Sending Secrets
Before analyzing a project:
- Remove API keys
- Redact credentials
- Exclude
.envfiles from analysis
Review Generated Changes
Never automatically commit AI-generated code without review. Always inspect changes carefully before applying them to your codebase.
Understand API Usage
Each CLI command sends data to the API. Review API pricing and data handling policies regularly.
Frequently Asked Questions
What is Claude Code CLI?
Claude Code CLI is a command-line tool that enables developers to work with Claude's AI coding features right from the terminal, including code analysis, refactoring, and documentation generation.
What operating systems support Claude Code CLI?
Claude Code CLI supports macOS, Linux, Windows WSL, and native Windows installations through PowerShell or CMD.
Can Claude Code CLI analyze an entire codebase?
Yes, Claude Code CLI can analyze multiple files and folders to help developers understand project structure, identify issues, and suggest improvements.
Is Claude Code CLI suitable for automation workflows?
Yes, developers commonly use Claude Code CLI in scripts, CI pipelines, and automated checks for tasks like code analysis, documentation, and refactoring.
What is the best way to start learning Claude Code CLI?
Start with small projects, experiment with different prompts and commands, and explore the official documentation to understand how the tool fits into your workflow.
Ready to Supercharge Your Development?
Claude Code CLI is a powerful addition to any developer's toolkit. Start with small projects, experiment with commands, and gradually integrate it into your automation workflows.