MCP 服务器

Example MCP Server

A Node.js/TypeScript MCP server template with sample tools (ping and system_info) that demonstrates how to build custom tools for Claude Desktop using stdio transport.

README

Example MCP Server

A simple Model Context Protocol (MCP) server implementation in Node.js with TypeScript for use with Claude Desktop.

What is MCP?

The Model Context Protocol (MCP) is an open protocol that enables AI models like Claude to interact with external tools and data sources. It allows Claude Desktop to call local or remote tools, retrieve information, and perform actions through standardized JSON-RPC messaging.

This server exposes tools that Claude can discover and invoke over a stdio (standard input/output) transport, making it perfect for local integrations.

Project Structure

.
├── src/
│   ├── mcp/
│   │   └── server.ts          # Main MCP server implementation
│   ├── tools/
│   │   ├── ping.ts            # Ping tool example
│   │   ├── system-info.ts     # System info tool example
│   │   └── registry.ts        # Tool registry & dispatcher
│   └── types/
│       └── index.ts           # TypeScript type definitions
├── dist/                      # Compiled JavaScript (generated)
├── package.json
├── tsconfig.json
├── mcp.json                   # Claude Desktop manifest
└── README.md

Features

✅ MCP-compliant JSON-RPC 2.0 server
✅ Stdio transport (works with Claude Desktop local tools)
✅ Two sample tools: ping and system_info
✅ Extensible tool registry system
✅ Proper error handling and validation
✅ TypeScript for type safety

Prerequisites

Node.js 16+ (or compatible version)
npm or yarn

Getting Started

1. Install Dependencies

npm install

2. Build TypeScript to JavaScript

npm run build

This compiles TypeScript from src/ to JavaScript in dist/.

3. Run the MCP Server

npm start

The server will start and listen for JSON-RPC requests on stdin.

Available Tools

ping

A simple test tool that returns "pong".

Request:

{"jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": {"name": "ping"}}

Response:

{"jsonrpc": "2.0", "id": 1, "result": {"content": [{"type": "text", "text": "pong"}]}}

system_info

Returns detailed system information including OS, architecture, CPU count, memory usage, and uptime.

Request:

{"jsonrpc": "2.0", "id": 2, "method": "tools/call", "params": {"name": "system_info"}}

Response:

{
  "jsonrpc": "2.0",
  "id": 2,
  "result": {
    "content": [{
      "type": "text",
      "text": "{\n  \"platform\": \"win32\",\n  \"arch\": \"x64\",\n  \"osType\": \"Windows_NT\",\n  ...\n}"
    }]
  }
}

MCP Protocol Methods

tools/list

Lists all available tools.

Request:

{"jsonrpc": "2.0", "id": 1, "method": "tools/list"}

Response:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "tools": [
      {
        "name": "ping",
        "description": "A simple ping tool...",
        "inputSchema": { "type": "object", "properties": {} }
      },
      ...
    ]
  }
}

tools/call

Calls a specific tool with optional arguments.

Request:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "tool_name",
    "arguments": { "arg1": "value1" }
  }
}

Response:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "content": [
      { "type": "text", "text": "Result here" }
    ]
  }
}

Registering with Claude Desktop

To use this MCP server with Claude Desktop:

Build the project:
```
npm run build
```
Locate your Claude Desktop configuration file:
- macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
- Windows: %APPDATA%\Claude\claude_desktop_config.json
- Linux: ~/.config/Claude/claude_desktop_config.json

Add the server to your claude_desktop_config.json:

{
  "mcpServers": {
    "example-mcp-server": {
      "command": "node",
      "args": ["/absolute/path/to/dist/mcp/server.js"],
      "env": {}
    }
  }
}

Replace /absolute/path/to with the full path to your project folder.

Restart Claude Desktop to load the new MCP server.
Claude will now be able to discover and call the tools provided by this server.

Adding New Tools

To add a new tool:

Create a new tool file in src/tools/ (e.g., src/tools/my-tool.ts):

import { Tool, ToolResult, ToolHandler } from "../types/index.js";

export const myTool: Tool = {
  name: "my_tool",
  description: "Description of what the tool does",
  inputSchema: {
    type: "object",
    properties: {
      param1: { type: "string" },
    },
    required: ["param1"],
  },
};

export const myToolHandler: ToolHandler = async (args) => {
  // Implementation
  return {
    content: [{ type: "text", text: "Result" }],
  };
};

import { myTool, myToolHandler } from "./my-tool.js";

const toolRegistry: Map<string, ToolEntry> = new Map([
  // ... existing tools
  ["my_tool", { definition: myTool, handler: myToolHandler }],
]);