Claude Code

Claude Code is Anthropic's agentic command-line coding tool that operates directly in your terminal, reading and understanding your entire codebase to perform complex programming tasks autonomously. Unlike editor-based AI tools, Claude Code works at the project level — planning multi-step changes, editing files, running commands, and iterating until the task is complete.

• Autonomous coding — describe a feature, bug fix, or refactor and Claude Code plans the approach, edits the right files, and verifies the result
• Codebase understanding — indexes and reasons over your entire project to make contextually accurate changes
• Terminal integration — runs tests, linters, build commands, and git operations as part of its workflow
• Multi-file editing — makes coordinated changes across many files while maintaining consistency
• Git-aware workflow — creates commits, branches, and even draft pull requests with meaningful descriptions

Senior developers and engineering teams use Claude Code for complex tasks that require understanding project-wide context: large refactors, migrating frameworks, writing comprehensive test suites, fixing subtle bugs, and implementing features that touch many files. It is particularly effective for tasks that are tedious but well-defined.

Claude Code runs entirely in your terminal with direct filesystem access — no browser, no cloud IDE, no code leaving your machine (except via the API). It works with any language, any framework, and any project structure.

1. Install Claude Code globally via npm:

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

2. Set up authentication (choose one):
   • API key: Set the ANTHROPIC_API_KEY environment variable
   • Claude Max subscription: Claude Code is included with the Max plan — authenticate via browser when prompted
3. Navigate to your project directory and run:

   claude

4. Start describing tasks in natural language. Examples:
   • “Write unit tests for the auth module”
   • “Refactor the database layer to use connection pooling”
   • “Find and fix the bug causing the 500 error on /api/users”
5. Pricing:
   • API usage: Pay-per-token via your Anthropic API key (Claude Sonnet ~$3/$15 per million input/output tokens)
   • Claude Max ($100/mo or $200/mo): Included usage with higher limits