Most developers stop at CLAUDE.md. That's layer 1. A production Claude Code harness needs 5 layers: memory, tools, permissions, hooks, and observability.

Here's the full setup guide. Claude Code harness has 5 layers: Memory — CLAUDE.md, MEMORY.md, .claude/commands/ Tools — MCP servers (sweet spot: 2–3) Permissions — settings.json allow/deny lists Hooks — PreToolUse/PostToolUse verification O