You built one MCP tool in Module 9.2. Now you build a real product: TutorClaw, an AI tutor with 9 tools that teaches the rest of this book.
TutorClaw is the case study that ties Module 9 together. You design 9 tools, describe each one to Claude Code using the mcp-builder skill, steer the implementation, and verify the result. The same describe-steer-verify cycle from Module 9.2, scaled to a real product.
Everything runs locally. JSON files store learner state. Markdown files hold course content. Stripe is the one external service because monetization IS the product. No database servers, no cloud storage, no deployment infrastructure. You spend your time on product design, tool quality, context engineering, and agent identity, not SSL certificates and boto3 scripts.
By the end of this chapter, you will have built a complete 9-tool MCP server, connected it to OpenClaw, tested it end-to-end from WhatsApp, added Stripe monetization, written a full pytest suite, and given your agent a distinct identity as a tutor.
Phase 1: Blueprint (Module 9.3, Chapters 1-2) establishes the mental model: 9 tools, tier access, platform inversion. Design every tool on paper before writing a single line of code.
Phase 2: Local Build (Module 9.3, Chapters 3-8) builds all 9 tools using Claude Code and the mcp-builder skill. JSON for state, local files for content, mock auth. Each tool gets careful design time via describe-steer-verify.
Phase 3: The Harness (Module 9.3, Chapters 9-12) adds the context that makes 9 tools work together: AGENTS.md for orchestration, refined tool descriptions for accurate selection, and a pytest suite that proves everything works.
Phase 4: Monetize (Module 9.3, Chapters 13-15) adds the business layer: tier gating, Stripe checkout, and a complete free-to-paid upgrade flow. Stripe is the one external integration because monetization IS the product.
Phase 5: Identity and Polish (Module 9.3, Chapters 16-19) gives TutorClaw a personality: shim skill for offline resilience, SOUL.md and IDENTITY.md for agent identity, channel routing for scope, and hardening for production readiness.
Phase 6: Reflect and Ship (Module 9.3, Chapters 20-21) publishes to ClawHub and audits the complete system against the original design. Everything you built locally is the product. Database servers, cloud storage, and deployment are scaling challenges for later, not product challenges for now.