mcp with socket

package.json

{
    "type": "module",
    "dependencies": {
        "@coinpaprika/api-nodejs-client": "^2.0.0",
        "@modelcontextprotocol/sdk": "^1.7.0",
        "ws": "^8.18.1",
        "zod": "^3.24.2"
    }
}

server.js

import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js"
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js"
import { z } from "zod"
import { WebSocketServer } from 'ws'

const server = new McpServer({
  name: "MCP Server Boilerplate",
  version: "1.0.0",
})

// Function to send WebSocket message asynchronously
async function sendWebSocketMessage(a, b) {
  return new Promise((resolve, reject) => {
    try {
      // Broadcast to all connected clients
      wss.clients.forEach(client => {
        if (client.readyState === WebSocket.OPEN) {
          const response = {
            status: 'success',
            timestamp: new Date().toISOString(),
            result: a + b,
            message: 'Calculation completed successfully'
          };
          client.send(JSON.stringify(response));
        }
      });
      resolve(`Sent WebSocket message with result: ${a + b}`);
    } catch (error) {
      reject(`Error sending WebSocket message: ${error.message}`);
    }
  });
}

server.tool("add", "Add two numbers", { a: z.number(), b: z.number() }, async ({ a, b }) => ({
  content: [{ type: "text", text: await sendWebSocketMessage(a, b) }],
}))

// Create WebSocket server
const wss = new WebSocketServer({ port: 8080 })

wss.on('connection', (ws) => {
   
  ws.on('message', (message) => {
    try {
      const data = JSON.parse(message.toString()) 
      
      // Create a JSON response
      const response = {
        status: 'success',
        timestamp: new Date().toISOString(),
        received: String(data.a + data.b),
        message: 'Message received successfully'
      }
      
      // Send JSON response
      ws.send(JSON.stringify(response))
    } catch (error) {
      // Handle JSON parsing errors
      const errorResponse = {
        status: 'error',
        timestamp: new Date().toISOString(),
        error: 'Invalid JSON format',
        message: error.message
      }
      ws.send(JSON.stringify(errorResponse))
    }
  })

  ws.on('close', () => {
    // console.log('Client disconnected')
  })
})
 
const transport = new StdioServerTransport()
await server.connect(transport)