Chapter 20 Exercises

These exercises help you build complete MCP Apps powered by the standard SDK APIs.

AI-Guided Exercises

The following exercises are designed for AI-guided learning. Use an AI assistant with the course MCP server to get personalized guidance, hints, and feedback.

  1. Build a Widget-Enabled MCP Server (60 min)

    • Create a server with ToolInfo::with_ui() and UIResource::html_mcp_app()
    • Build a widget using the ext-apps App class with all required handlers
    • Return structuredContent from a tool and render it in the widget
    • Bundle with Vite and test with cargo pmcp preview

  2. Multi-Host Validation (30 min)

    • Add with_host_layer(HostType::ChatGpt) to your server
    • Validate metadata with mcp-tester apps http://localhost:3000
    • Run with --mode chatgpt and --mode claude-desktop to check host-specific compliance
    • Fix any warnings reported by mcp-tester apps --strict

  3. External Resource Loading (45 min)

    • Add external image loading to a widget
    • Declare CDN domains using WidgetCSP on the server side
    • Implement the fetch-blob pattern in the widget for cross-host compatibility
    • Test in cargo pmcp preview and verify images render correctly

Prerequisites

Before starting these exercises, ensure you have:

  • Completed all previous chapters
  • cargo-pmcp installed (cargo install cargo-pmcp)
  • Node.js installed (for Vite bundling)
  • Understanding of MCP resource patterns

Next Steps

Congratulations! You've completed the PMCP course. Continue your learning: