Building Claude Code isn't about better prompts.

The architecture is built around five core components: * Master Agent Loop – Drives the perception → reasoning → tool execution cycle until a task is complete. * Typed Tool Registry – Safely dispatches tools like "bash", "read", "write", "grep", and "glob" using strict schemas. * Context Management – Combines skill injection, conversation compression, and persistent memory to handle long-running sessions. * Permission Governance – Enforces Always Allow, Always Deny, and User Approval policies with lifecycle hooks for every tool call. * Multi-Agent Coordination – Enables isolated sub-agents, asynchronous delegation, FSM-driven workflows, and Git worktree isolation for parallel execution. This harness is what transforms an LLM into a reliable software engineering agent. Over the coming posts, I'll break down each component and show how to build a production-grade AI coding agent from scratch. #AI #LLM #ClaudeCode #AgenticAI #SoftwareEngineering #AIEngineering #DeveloperTools #GenerativeAI #SystemDesign