What is Claude Code? A Complete Guide to Pricing, Features, and Security

Chronist Team Chronist Team

Among constantly emerging developer support tools, Claude Code released by Anthropic stands out. Rather than mere code completion, it functions as an “autonomous agent” supporting everything from design to editing, testing, and version control—a potential reliable development partner.

This article clearly explains Claude Code’s basic features, differences from other tools, and concrete usage scenarios.

Table of Contents

What is Claude Code?

Anthropic’s “Agentic (autonomous) coding CLI” is a development support tool that behaves like a human assistant. Rather than just completing code fragments, it can survey entire projects, autonomously considering “where and how to fix” and “how changes affect other areas” before executing tasks—that’s its defining characteristic.

Specifically, it operates in terminals or VS Code, handling complete development workflows including modifying code across multiple files, running tests, committing, and creating pull requests. To ensure even first-time users can safely delegate tasks, it’s designed to confirm “Is this change acceptable?” before each action.

Claude Code combines both usability and execution capability, unlike other AI coding support tools. The following table compares differences with representative tools.

Feature Comparison with Other Representative Tools

ItemClaude CodeGitHub Copilot ChatCursor
Codebase RecognitionAutonomous exploration of entire projectsCentered on opened filesSame
Execution EnvironmentLocal CLI (no cloud required)VS Code / JetBrains extensionsDedicated IDE
Action ScopeEdit, test, Git operations, PRPrimarily editing supportEdit + partial execution
ModelClaude Opus 4/ Sonnet 4, etc.GPT-4 seriesClaude / GPT-4

Thus Claude Code isn’t merely a “code completion tool” but fulfills an “agentic” role covering execution and version control, capable of handling complex projects.

Claude Code Usage Examples and Practical Effects

Claude Code goes beyond simple code generation or completion, offering features that automate and streamline diverse tasks directly connected to actual operations. Below we introduce five particularly practical representative use cases.

  • Codebase Q&A

For questions like “Where’s authentication processing?” it explores the entire codebase, identifies relevant locations, and responds with summaries. Enables rapid overall project comprehension.

  • Bug Fixing & Test Automation

Communicating errors discovered via npm test or CI in natural language prompts correction candidates and specific content. Automatic retesting after corrections enables efficient bug response with minimal rework.

  • Refactoring & Large-Scale Modifications

ESLint, type definition errors, library version updates, and other multi-file changes are appropriately rewritten after understanding impact scope. Maintains consistency even across broad modifications.

  • Issue to PR Completion

Reads issues registered in GitHub or GitLab, implements necessary changes as code. Can execute from Git commits to pull request creation in one batch. Enables significant time savings for teams wanting detailed work management.

  • CLAUDE.md Memory

Using the /init command, project characteristics, design policies, and cautions can be organized in Markdown format. This serves as “memory” for you and your team, useful as handover material or explanatory documentation for new project members.

Initial Setup (Complete in 5 Minutes)

Claude Code is a CLI tool installed and used in local environments, requiring no cloud integration or complex configuration for setup. Here we introduce basic implementation procedures for developers to start using it quickly. With minimal special dependencies, setup is possible via identical steps in any OS environment as long as Node.js is installed.

  1. Prepare Node.js 18+ and execute:

npm install -g @anthropic-ai/claude-code

  1. Navigate to project directory:

cd your-project-directory

  1. Launch CLI:

claude

  1. Authentication:

OAuth integration via Anthropic Console or Claude Max plan. Enterprise use can also connect to Bedrock / Vertex AI.

  • Supports macOS / Linux / WSL2 (Windows), 4 GB+ RAM recommended.

Frequently Used Commands & Shortcuts

Since Claude Code is primarily terminal-based, understanding several key commands and shortcuts is important for daily use. Here we list particularly high-frequency, practically useful commands. While intuitive syntax familiar to CLI users is central, flexibly switching between interactive and one-line modes enables more versatile task handling.

CommandPurpose
claudeLaunch interactive mode
claude -p "query"Single-line execution (non-interactive)
claude --continueResume recent session
claude commit / create a prAutomate Git operations
/initGenerate CLAUDE.md
/configChange settings (model switching, etc.)
  • Shift+Enter for line breaks, immediate memory addition with # prefix, Vi keybindings also possible via /vim.

  • One-liner execution accepts pipe input like cat error.log | claude -p "explain the cause".

Practical TIPS

Here we introduce practical refinements and usage know-how for naturally incorporating Claude Code into daily operations. Covering hints for integrating as part of development flows and operation examples for effective use in specific use cases, this content deepens practical understanding.

  • Onboarding

Confirm project overview with > summarize this project and create CLAUDE.md via /init for use as simple internal documentation.

  • Rapid Debugging

Simply paste error logs and ask “How do I fix this error?” for correction code and verification methods.

  • Parallel Development

Use claude --resume to switch work content, progressing without confusion.

  • Large-Scale Refactoring

Consult on major change strategies using > think longer about, then smoothly review entire codebase via /review.

Learning Skills Systematically with Anthropic’s Official Course “Claude Code in Action”

Beyond daily usage TIPS, Anthropic’s official learning course “Claude Code in Action” enables systematic learning from basics to applications. Through exercise formats using practical challenges, you can acquire and organize skills directly connected to real work.

Learning Content Structure

CategoryMain Learning ContentLearning Points
Essential Skills- Understanding AI architecture- Context management via CLAUDE.md- Distinguishing Planning/Thinking mode usageGrasp project overview, achieving efficient interactions
Applied Skills- Custom command design- Automation via Hooks (type checking, formatting, etc.)- MCP server integration- GitHub PR review supportApply complex changes and automation at production level, improving development efficiency

Practical Exercise Examples

  • Preventing Type Change Propagation Omissions: Run tsc --noEmit with PostToolUse for immediate detection of modification oversights

  • Preventing DB Query Duplication: Automate existing function verification, promoting reuse

  • Protecting Confidential Files: Block .env access with PreToolUse

  • Improving UI Generation Accuracy: Verify display results with Playwright MCP, refining prompts

Prerequisites for Course Participation

  • Basic CLI operation

  • Git usage experience

  • Node.js and npm environment setup skills

  • (Optional) AWS Bedrock or Google Vertex AI connection configuration

With official procedures in place, learning can begin quickly with foundational skills.


For those thinking “I’ve become comfortable using Claude Code practically, but want more systematic learning,” this course offers opportunities to comprehensively acquire production-ready skills.

※Details here: Claude Code in Action (Anthropic Official)

You may also want to read

Claude Code Official Tips Collection: Practical Techniques to Boost Productivity

Security Design and Safe Operation

The most important aspect of using Claude Code is visualizing “what scope generative AI can operate within” and minimizing risks. This section organizes Claude Code’s safety design philosophy and operational precautions.

First, Claude Code has sufficient security considerations for confident use in development settings.

All processing executes in local environments, with communication directly interfacing Anthropic’s API, without intermediary third-party servers. This minimizes leakage risks when handling confidential codebases.

Furthermore, safe design always requesting user confirmation before operations eliminates concerns about “unauthorized changes” even with automated processing.

For streamlining development and verification, the --dangerously-skip-permissions option can skip confirmations, but this is not recommended in production environments.

Cost Design and Usage Limit Understanding

Claude Code employs two primary billing structures—“subscription (Pro/Max)” and “API pay-as-you-go”—designed to support individual users to enterprise teams broadly. Flexible selection according to usage purpose is characteristic.

Billing StructureUse CasesPricing (Estimate)
Subscription (Pro/Max)Daily use / Using Claude Code in both web and terminalPro: $17/month (annual) or $20/month, Max: $100 or $200/month (5×/20× usage)
API Pay-as-you-go (Anthropic API)Charge per use. For PoC or automation with fine-grained controlDepends on usage (unit prices by model)

No standalone Claude Code subscription exists. Included in Pro/Max (individual) or Team Premium seats, or used as API pay-as-you-go.

About Rate Limits

From August 2025, Anthropic introduced new weekly usage limits to maintain overall service stability. Primarily for controlling heavy users, understanding the mechanism helps prevent operational troubles. Below are key limits and response points.

  • Session System + Weekly Limits

Paid plans have 5-hour session limits plus weekly limits (check remaining at Settings → Usage).

  • Shared Counting

Claude main and Claude Code usage counts toward common limits.

  • on the web Handling

Operates as cloud sessions, sharing limits with other Claude Code usage.

  • Team Weekly Guidelines (Premium Seats)

Sonnet 4: 50–95 hours/week, Opus 4/4.1: 3–7 hours/week as limit guidelines. After reaching limits, continue via Extra usage (when enabled) switching to standard API rates.

  • Individual (Pro/Max) Additional Usage

Even after reaching limits, continuation possible via enabling Extra usage (paid) or switching to Console API credits (optional).

Summary

Claude Code is essentially “a full-stack AI engineer resident in your terminal”. Setup is just one line: npm install. Natural language enables completing “think → write → test → PR,” making it

An immediate solution to workplace challenges like:

“Code reviews bottleneck and halt development”

“Explaining codebases to newcomers creates heavy burden”

First try the /initclaude commit flow in small projects to experience its potential.