BookService — protoc-gen-go-mcp Example ¶

⚠ Experimental — build-time codegen (experimental/ext/protogen), not a wire protocol.

End-to-end example demonstrating all three MCP primitives generated from proto annotations.

MCPKit Features Used ¶

Category	Feature
Core	core.ToolContext, core.ResourceContext, core.PromptContext, core.CompletionRef
Experimental	experimental/ext/protogen — protoc-gen-go-mcp code generator
MCP primitives	Tools, Resources (templates), Prompts, Completions, Sampling, Elicitation
Proto annotations	mcp_tool, mcp_resource, mcp_prompt, mcp_service, mcp_sample, mcp_elicit

What it shows ¶

Proto annotation	MCP primitive	Generated names
mcp_tool	Tool	books_search (with result summary + structured output)
mcp_resource	Resource template	book://{book_id}, author://{author_id}/books
mcp_prompt	Prompt	books_summarize, books_recommend_books
mcp_service	Namespace	All names prefixed with books_

Quick start ¶

just generate   # Generate Go code from protos
just run        # Start MCP server on :8080

Testing ¶

go test -v .    # Run e2e tests (tool calls, resource reads, prompt listing)

Prompts to try ¶

• “Search for books about Go programming” — calls books_search tool
• “Tell me about book 1” — reads book://{book_id} resource
• “What books has author 1 written?” — reads author://{author_id}/books resource
• “Summarize the book collection” — uses books_summarize prompt
• “Recommend books for someone learning distributed systems” — uses books_recommend_books prompt

Add to Claude Desktop ¶

Add this to your claude_desktop_config.json (or VS Code MCP settings):

{
  "mcpServers": {
    "bookservice": {
      "command": "go",
      "args": ["run", "."],
      "cwd": "/path/to/mcpkit/examples/protogen/bookservice",
      "transport": "streamable-http",
      "url": "http://localhost:8080/mcp"
    }
  }
}

Or if you’ve built the binary:

{
  "mcpServers": {
    "bookservice": {
      "command": "/path/to/mcpkit/examples/protogen/bookservice/bin/bookservice",
      "transport": "streamable-http",
      "url": "http://localhost:8080/mcp"
    }
  }
}

Screenshots ¶

Tools, resources, and prompts generated from proto annotations ¶

Search results for “Go programming” ¶

Add to Claude Code ¶

claude mcp add bookservice --transport streamable-http http://localhost:8080/mcp

Or in .claude/settings.json:

{
  "mcpServers": {
    "bookservice": {
      "type": "streamable-http",
      "url": "http://localhost:8080/mcp"
    }
  }
}

Next steps ¶

• Getting started
• protogen design