What Is Claude Code?

Claude Code is Anthropic's official AI coding assistant delivered as a command-line interface (CLI). Unlike IDE plugins that offer inline autocomplete, Claude Code operates as an interactive agent that reads your entire project, understands your codebase in context, and executes multi-step coding tasks — from writing new features to debugging production bugs to refactoring legacy modules.

Step 1: Install Claude Code CLI

Open your terminal and run:

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

Verify the installation and authenticate:

claude --version
claude auth login

Step 2: Open Your Project

cd /path/to/your/project
claude

Step 3: Describe Your Task in Plain English

Simply describe what you want: Add rate limiting to the /api/login endpoint — max 5 requests per minute per IP. Claude Code will read relevant files, plan the implementation, write the code, and show you a diff for review.

Step 4: Review the Proposed Changes

Claude Code never applies changes without showing a diff first. Type yes to apply, no to reject, or type a follow-up to adjust.

Step 5: Apply and Test

Run your test suite after applying. If tests fail, paste the error back into Claude Code — it will diagnose and fix in the same session.

Step 6: Slash Commands

CommandWhat It Does
/reviewAudit a file for bugs and security issues
/explainGet a plain-English explanation of code
/commitGenerate a semantic commit message
/testGenerate unit tests for a function

Advanced Tips

  • CLAUDE.md file: Add project-specific coding standards at your repo root
  • MCP servers: Connect external tools via the Model Context Protocol
  • Cost management: Use /clear to reset context between unrelated tasks

Conclusion

Claude Code is one of the most capable AI coding tools available in 2026. Start with small, well-scoped tasks, review every diff carefully, and gradually expand to larger autonomous workflows.