What Is Claude Code? A Complete 2026 Guide: Install, Setup, and What You Can Do

"Claude Code comes up all the time lately, but what does it actually do?" "How is it different from Cursor?" — as interest in AI coding tools continues to grow, these are questions I hear constantly from fellow engineers.

Claude Code is a terminal-based AI coding agent developed by Anthropic. Just by giving it natural-language instructions from your terminal, the AI autonomously handles code generation, editing, debugging, refactoring, and Git operations.

This article walks through everything: what Claude Code is, how to install it, the basics of using it, what it can do, and the pricing plans — a full picture of how to get started and put it to work. I've spent 17 years in IT, and today I use Claude Code as the core tool of my agentic coding workflow (a development style where you hand primary authorship to the AI).

What Is Claude Code?

Claude Code is a terminal-based (command-line) AI coding agent that Anthropic released in February 2025.

While traditional code completion tools (like GitHub Copilot) "predict the next line," Claude Code is fundamentally different in that it autonomously carries out entire tasks. Give it a natural-language instruction — "fix this bug," "write tests," "create a PR" — and it handles reading and writing files, running commands, and Git operations, end-to-end.

Claude Code's Key Characteristics

• Agent-based: Once given an instruction, it autonomously executes the multiple steps required to complete the task
• Whole-codebase awareness: It works with an understanding of your project's file structure, dependencies, and coding conventions
• Tool execution: It selects and runs tools itself — terminal commands, file reads/writes, web browsing, and so on
• Multimodal: Beyond code, it handles screenshot analysis, log parsing, and document generation
• Git integration: Commits, branch creation, PR creation, and conflict resolution are all covered

In a sentence: Claude Code is less an "AI pair programmer" and more an "AI junior engineer." Hand it a task and it investigates, thinks, implements, and verifies — autonomously.

Pronunciation and Official Name

"Claude Code" is pronounced "Klawd Code," per Anthropic's official pronunciation.

The official name is Claude Code. Variants like "Claude Code CLI" and "Claude Code Agent" are unofficial. That said, extensions for VSCode and JetBrains IDEs and desktop apps are also available — so usage extends well beyond the terminal.

Installing Claude Code

As of April 2026, there are three main ways to install Claude Code.

Option 1: Native Installer (recommended)

This is Anthropic's most recommended option. It doesn't require Node.js and supports auto-updates.

macOS / Linux / WSL:

Windows PowerShell:

Windows CMD:

Once installed, just type claude in your terminal to launch it.

Option 2: Homebrew (macOS)

claude-code is the stable channel (about a week behind), while claude-code@latest is the bleeding-edge channel. Homebrew doesn't auto-update, so you'll need to run brew upgrade claude-code manually.

Option 3: npm (deprecated, for compatibility)

Requires Node.js 18+. As of 2026, the npm version is deprecated in favor of the native installer.

System Requirements

Initial Setup After Installation

On first launch, a browser window opens and prompts you to sign in to your Anthropic account.

Running claude doctor automatically detects environment issues (Node.js version, network config, and so on). If something isn't working, try this command first.

Desktop App

For those less comfortable with the terminal, there's also a desktop app. It's available for macOS and Windows, and lets you work with a GUI diff view. You can download it from the official site.

Basic Claude Code Usage

Launching and Exiting

Claude Code treats the current directory as the project root. Always launch it from the root directory of your project.

For commands, language settings, and other practical usage details, see Claude Code Usage Guide.

Natural-Language Instructions

Once launched, just type instructions in natural language. Both English and Japanese work.

Slash Commands

Special commands prefixed with / are also available.

Configuring Projects with CLAUDE.md

Drop a CLAUDE.md file in your project root and Claude Code will pick up project-specific rules and conventions.

At aduce, we put a CLAUDE.md in every project and share project-specific development rules with the AI. This alone dramatically changes the quality of "development assistance that understands project context."

You can also place global settings in ~/.claude/CLAUDE.md to set rules shared across all projects (response language, commit message conventions, and so on). For more, see How to Unify Your Dev Experience with a Global CLAUDE.md.

What You Can Do with Claude Code

Here are the tasks Claude Code handles, organized by category based on my own practical experience.

Code Generation and Editing

Testing

Git Operations

Documentation and Analysis

Infrastructure / DevOps

Real-World Usage

Here's a typical day at aduce using Claude Code.

Morning (9:00-10:00): PR Review

Claude Code pulls the diffs from git log and reviews them for code quality, security, and performance.

Late morning (10:00-12:00): Feature Implementation

Claude Code implements it consistently, drawing on an understanding of the project's existing code.

Early afternoon (13:00-15:00): Bug Fixing

It analyzes the log, traces the relevant code, proposes a fix, and confirms the fix with tests — all in one go.

Late afternoon (15:00-17:00): Refactoring / Docs

Claude Code handles large transformations in bulk — work that would take half a day manually finishes in 1-2 hours.

Claude Code Pricing Overview

Using Claude Code requires a paid plan. Here are the main options.

A recommended starting point: Try Pro ($20/month) for one month. If you start hitting rate limits frequently, upgrade to Max.

For detailed plan comparisons, cost-benefit analysis, and recommendations by team size, see Claude Code Pricing: A Complete Plan Comparison.

Tips for Getting the Most Out of Claude Code

1. Flesh Out CLAUDE.md

The highest-leverage thing you can do is document your project's rules in CLAUDE.md. Even just writing down coding standards, test policies, and prohibitions dramatically improves Claude Code's output quality.

2. Be Specific in Your Instructions

Not "improve the code" but "add rate limiting to the login function in src/auth.ts, capped at 5 requests per minute." The more specific the instruction, the better the result.

3. Work in Stages

Rather than throwing a huge task at it in one go, step through design → implementation → tests → review. Check Claude Code's output at each stage and course-correct — that's the trick.

4. Manage Context with /compact

Long conversations consume the context window. At natural task breaks, use /compact to summarize the conversation and reset — performance stays steadier.

5. Leverage Hooks, Skills, and MCP

Claude Code's extensions can dramatically streamline your workflow.

• Hooks: Mechanism for automatically running shell commands before or after tool execution
• Skills: Define custom slash commands to run routine tasks with a single command
• MCP: Protocol for integrating with external services and tools

For Skills in depth, see Automating Your Development Workflow with Claude Code Skills.

Summary

Claude Code is an AI coding agent that autonomously executes everything from code generation to Git operations — driven by natural-language instructions from your terminal.

Claude Code is the next step after "code completion" — an "AI agent." The biggest wins come not just from learning the tool, but from clearly separating what you hand to Claude Code from what you still do yourself. That shift in development style is where the real impact lives.

For VSCode usage, see Claude Code × VSCode Complete Guide. For external tool integration, see Claude Code × MCP Integration Guide.

For comparisons with other AI coding tools, see Claude Code vs Cursor In-Depth Comparison and Claude Code vs OpenAI Codex Comparison. For GitHub Actions integration, see Claude Code × GitHub Actions Integration Guide; for Hooks-based automation, Claude Code Hooks Complete Guide; for multi-agent development, Introduction to Claude Code Agent Teams; and for enterprise-scale security, Claude Code Security Considerations.

At aduce Inc., we provide comprehensive IT advisory support — everything from helping you adopt AI tools including Claude Code to building out development processes that take full advantage of agentic coding. If you're considering Claude Code but aren't sure how to fold it into your own development flow, please feel free to reach out via Contact.

References

• Claude Code Official Documentation
• Plans & Pricing | Claude by Anthropic
• Claude Code - npm