What is Claude Code?

Claude Code is Anthropic's agentic coding tool — it reads and writes your repo and runs commands.

Claude Code is Anthropic's agentic coding tool. Unlike a chat window where you copy and paste, Claude Code works directly inside your project: it reads your files, edits them, runs commands, and checks the results.

What it can do

  • Scaffold new features and pages across multiple files.
  • Refactor and rename across a codebase.
  • Run your dev server, tests, and linters, then fix what breaks.
  • Work with git — create branches and commits.

Where it runs

Claude Code runs as a command-line tool, and also inside IDEs, the desktop app, and the web. It works where you already work.

Claude Code reads a task and edits files in your repositoryYour task"Add a dark mode toggle"Claude Coderead - edit - runYour repoindex.htmlstyles.cssapp.js
Claude Code turns a plain-English task into real edits in your repository.

Example

Example · bash
# In your project directory, start Claude Code and give it a task:
claude

# Then type a natural-language instruction, for example:
#   "Add a dark mode toggle to the header and persist the choice in localStorage."
# Claude Code will edit the relevant files and show you the diff.

When to use it

  • Use Claude Code to add a new API route across multiple files without manually tracking every import and export.
  • Let Claude Code run your test suite after making changes and fix failing tests autonomously in your CI pre-check.
  • Give Claude Code a bug description and have it trace the issue through your codebase and commit the fix.

More examples

Install Claude Code globally

Installs the Claude Code CLI that can then be run from any project directory.

Example · bash
npm install -g @anthropic-ai/claude-code
claude --version

Launch Claude Code in a project

Opens Claude Code inside a project so it has access to read and edit the repo's files.

Example · bash
cd /path/to/my-web-app
# Start an interactive session
claude
# Or run a one-off task inline
claude "Add an /api/health endpoint that returns {status:'ok'}"

Claude Code vs. a chat window

Highlights the key difference: Claude Code writes directly to disk instead of returning text to copy.

Example · bash
# Chat window: you copy the code manually
# Claude Code: it edits the file directly
claude "Rename the Button component to PrimaryButton in all files"
# Claude Code will grep, edit, and confirm each change

Related

claude cc tasksclaude cc vs chat

Discussion

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