How Claude Code Works is a technical documentation project that analyzes the architecture and internals of Claude Code, an AI coding agent system.
The project addresses the challenge of understanding a large production-grade AI agent codebase by providing structured analysis of how Claude Code handles real-world complexity. Rather than treating the codebase as a monolithic whole, the documentation breaks down key architectural decisions and design patterns, covering areas such as context management for conversations spanning millions of tokens, coordination of multiple built-in tools, latency optimization through pipelining, and safety mechanisms for preventing dangerous command execution. The approach combines reverse engineering with documentation, using Claude Code itself as a tool to help extract and explain the underlying design principles from the source code.
This project suits developers who want to build their own AI agents or gain deeper understanding of production-grade agentic systems. It is particularly valuable for those working on systems that must handle scale and complexity beyond typical demo implementations. The documentation covers sixteen topic areas spanning from core agent loops to security safeguards. A companion project provides a clean-room educational implementation in TypeScript and Python, allowing developers to learn by building a similar system from scratch.
The project maintains active documentation updates in response to Claude Code's evolving feature set, including recent additions like loop engineering and dynamic workflow capabilities. Analysis focuses on reverse-engineered understanding rather than official specifications, with the maintainers explicitly noting this represents independent research and inference rather than Anthropic's actual internal design. The project is structured as an ongoing learning effort, with the maintainers committing to continuous updates as new features are released and analyzed.