This repository provides the source code for Anthropic's Claude Code CLI, an AI programming assistant. It is intended for learning, research, and analysis of the tool's architecture and implementation, enabling users to understand how complex AI-powered command-line tools are built.

How It Works

The project leverages TypeScript/TSX with the Bun runtime and package manager. Its terminal UI is rendered using React with the Ink framework, managed by Commander.js for CLI parsing. Core components include a modular tool system (Bash, file operations, web search) with JSON Schema validation, a command system supporting prompt, local, and dialog types, and an API communication layer for interacting with Anthropic's backend. It implements the Model Context Protocol (MCP) for AI tool interoperability and features a skill system and multi-agent collaboration capabilities.

Quick Start & Requirements

This repository contains only source code for learning and analysis; it does not include complete build configurations or dependencies for running the CLI. The primary runtime and package manager is Bun. Setup for direct use is not supported by this repository.

Highlighted Details

• Modular Tool System: Each tool is an independent module with input validation (JSON Schema), execution logic, permission control, and output formatting.
• Command System: Supports diverse command types including prompt-based, local execution, and dialog interactions.
• MCP Protocol: A full implementation of the Model Context Protocol facilitates AI tool interoperability via Stdio, SSE, resource management, and tool invocation.
• Extensible Skills & Agents: Features a skill framework for built-in, plugin, and custom skills, alongside a multi-agent system for task delegation and parallel execution.
• React-based CLI UI: Utilizes Ink and React for a dynamic and interactive terminal user interface.

Maintenance & Community

The project was last updated on March 31, 2026. No specific community links (Discord, Slack) or details on contributors, sponsorships, or partnerships are provided in the README.

Licensing & Compatibility

Source code copyright is held by Anthropic, PBC. This project is strictly for educational purposes only. Consequently, commercial use or integration into closed-source projects is not permitted.

Limitations & Caveats

This repository is solely for educational and research purposes, offering source code without complete build configurations or dependencies. It is not a deployable product, and its restrictive licensing prohibits any use beyond non-commercial educational study.