Claude Code CLI is Anthropic's official development toolkit integrating Claude into the software engineering workflow. It includes a VSCode extension, terminal interface, and API bindings for language-agnostic development. Claude Code can read your codebase, understand project structure, perform multi-file edits, run commands, and iterate based on feedback. Unlike monolithic IDEs (Cursor, Windsurf), Claude Code is modular—you can use it in your existing editor or run it from the terminal. It supports any Claude model (including Claude 3.5 Sonnet and Opus for long-context work) and integrates with git for transparent change tracking.