Claude Code — Agentic Coding CLI by Anthropic

Claude Code — Agentic Coding CLI

Claude Code is Anthropic’s terminal-based AI coding agent. Unlike IDE plugins that add AI to your existing editor, Claude Code operates in your terminal — reading your files, running shell commands, editing code, and committing changes, all driven by natural language instructions.

How It Works

You run claude in your terminal, describe what you want, and Claude Code:

Reads relevant files in your codebase
Plans what needs to change
Makes edits across multiple files
Runs tests or build commands to verify changes
Fixes errors if tests fail
Commits and describes the changes

All while keeping you in control — you can see every action and approve or reject changes.

Installation

# Install via npm (requires Node.js 18+)
npm install -g @anthropic-ai/claude-code

# Verify installation
claude --version

# Start a session in your project directory
cd my-project
claude

Key Capabilities

Capability	Example
Read codebase	Understands your entire project structure
Write + edit files	Creates and modifies files
Run commands	Executes shell commands, tests, builds
Git operations	Stages files, creates commits, reads diffs
Web search	Looks up documentation when needed
Multi-turn context	Remembers the full conversation and file state

Common Workflows

Fix a Bug

claude "The login form is not validating the email format. Fix it and add a test."

Claude Code will:

Find the login form component
Identify the missing validation
Add the validation logic
Write a unit test for it
Run the test suite to confirm it passes

Add a Feature

claude "Add a dark mode toggle to the settings page. Persist the preference in localStorage."

Refactor Code

claude "Refactor the UserService class to use dependency injection and write tests for each method."

Understand the Codebase

claude "Explain how authentication works in this project and draw a flow diagram."

Slash Commands

Command	Description
`/help`	Show available commands
`/clear`	Clear conversation history
`/compact`	Compact the conversation to save context
`/config`	Open configuration settings
`/memory`	View or edit persistent memory
`/review`	Review recent changes

CLAUDE.md — Project Instructions

Create a CLAUDE.md file at the root of your project to give Claude Code persistent instructions:

# Project: MyApp

## Stack
- Frontend: React + TypeScript
- Backend: Node.js + Express
- Database: PostgreSQL

## Conventions
- Use functional components (no class components)
- All functions must have JSDoc comments
- Tests go in __tests__ folder next to the source file
- Run `npm test` to verify changes

## Rules
- Never commit .env files
- Always run `npm run lint` before finishing

Claude Code Cloud

Claude Code Cloud allows Claude Code to run in a secure, sandboxed cloud environment — useful for:

Running long tasks without keeping your terminal open
Executing in CI/CD pipelines
Sharing sessions with team members

Claude Code vs Cursor vs Windsurf

Feature	Claude Code	Cursor	Windsurf
Interface	Terminal	IDE (GUI)	IDE (GUI)
Multi-file edits	Yes	Yes	Yes
Runs shell commands	Yes (core feature)	Yes (agent mode)	Yes (Cascade)
Git integration	Yes (native)	Yes	Yes
Model	Claude only	Claude, GPT-4o, Gemini	Claude, GPT-4o
Works in any editor	Yes (terminal)	VS Code fork only	VS Code fork only
Learning curve	Medium	Low	Low
Best for	Autonomous tasks	Visual AI editing	Fast AI editing

Pricing

Claude Code requires a Claude Pro plan ($20/month) or API access. Usage is billed against your Anthropic API usage in API mode.