MCP Server Template

A template for creating Model Context Protocol (MCP) servers in TypeScript. This template provides a solid foundation for building MCP-compatible servers with proper tooling, type safety, and best practices.

Features

• Full TypeScript support
• Container-based dependency injection
• Service-based architecture with DataProcessor interface
• Example tool implementation with tests
• Vitest testing framework
• Type definitions
• MCP SDK integration

Getting Started

Development

1. Install dependencies:

   npm install
   

2. Start the development server with hot reload:

   npm run dev
   

3. Build the project:

   npm run build
   

4. Run tests:

   npm test
   

5. Start the production server:

   npm start
   

Project Structure

src/
├── index.ts          # Entry point
├── interfaces/       # Interface definitions
│   └── tool.ts      # DataProcessor interface
└── tools/           # Tool implementations
    └── example.ts   # Example tool

Creating Tools

1. Export your tool and handlers following the example in src/tools/example.ts:

   // In your-tool.ts
   export const YOUR_TOOLS = [
     {
       name: "your-tool-name",
       description: "Your tool description",
       parameters: {
         // Your tool parameters schema
       },
     },
   ];
   
   export const YOUR_HANDLERS = {
     "your-tool-name": async (request) => {
       // Your tool handler implementation
       return {
         toolResult: {
           content: [{ type: "text", text: "Result" }],
         },
       };
     },
   };
   

2. Register your tool in the ALL_TOOLS and ALL_HANDLERS constants in src/index.ts:

   // In src/index.ts
   import { YOUR_TOOLS, YOUR_HANDLERS } from "./tools/your-tool.js";
   
   // Combine all tools
   const ALL_TOOLS = [...EXAMPLE_TOOLS, ...YOUR_TOOLS];
   const ALL_HANDLERS = { ...EXAMPLE_HANDLERS, ...YOUR_HANDLERS };
   

The server will automatically:

• List your tool in the available tools
• Handle input validation
• Process requests to your tool
• Format responses according to the MCP protocol

Testing

The template includes a built-in TestClient for local testing and the MCP Inspector for visual debugging.

Using TestClient

The TestClient provides a simple way to test your tools:

import { TestClient } from "./utils/TestClient";

describe("YourTool", () => {
  const client = new TestClient();

  it("should process data correctly", async () => {
    await client.assertToolCall(
      "your-tool-name",
      { input: "test" },
      (result) => {
        expect(result.toolResult.content).toBeDefined();
      }
    );
  });
});

Using MCP Inspector

The template includes the MCP Inspector for visual debugging of your tools:

1. Start the inspector:

   npx @modelcontextprotocol/inspector node dist/index.js
   

2. Open the inspector UI at http://localhost:5173

The inspector provides:

• Visual interface for testing tools
• Real-time request/response monitoring
• Tool metadata inspection
• Interactive testing environment

Local Testing with Cursor

To test your MCP server locally with Cursor:

1. Build and link the package:

   npm run build
   npm run link
   

2. Verify the binary works:

   npx example-mcp-tool
   

3. Add the server to Cursor:

   • Open Cursor settings
   • Navigate to the Features tab
   • Scroll down to MCP Servers section
   • Click “Add Server”
   • Select “Command” type
   • Give it a name (e.g., “Local Example Tool”)
   • Enter the command: npx example-mcp-tool
   • Click Confirm

4. Verify the server starts correctly in Cursor by checking the MCP Servers section shows your server as running.

Note: If you make changes to your code, remember to rebuild and relink:

npm run build
npm run link

When you’re done testing, you can unlink the package:

npm run unlink

This will remove the global symlink created during development.