About this project

Yuyu: Decoding Agent Harness (御舆：解码 Agent Harness) is a technical book compiled and authored by linthsinghua that offers an in-depth analysis of the Claude Code architecture, totaling 420,000 Chinese characters. The book is organized into four parts comprising fifteen chapters, plus four appendices. Part One, Foundations, builds a mental model of the agent programming paradigm, covering three core mechanisms: the conversation loop, the tool system, and the permission pipeline. Part Two, Core Systems, dives into four major subsystems: configuration management, the memory system, context management, and the hooks system. Part Three, Advanced Patterns, explores subagents and Fork mode, orchestrator-based multi-agent orchestration, the skills system and plugin architecture, and MCP integration with external protocols. Part Four, Engineering Practice, explains streaming architecture and performance optimization, Plan mode and structured workflows, and a six-step roadmap for building your own Agent Harness. The appendices provide a source code navigation map, a complete tool inventory, a feature flag quick reference, and a glossary. The book is licensed under CC BY-NC-SA 4.0, and its technical analysis is independent of Anthropic official sources.