Skip to main content

Your First MCP Server

Prerequisites​

  • Node.js installed (version 18 or higher recommended)
  • npm or yarn package manager

Create a directory​

Create a new directory called mcptooling

mkdir mcptooling

Package Depdendencies​

Install the required packages:

npm install @modelcontextprotocol/sdk zod

Execution Steps​

Save the code to a file (e.g., time-server.js)

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

const server = new McpServer({ name: "Time", version: "1.0.0" });

server.tool(
  "get-current-time",
  "Get the current time for a requested timezone",
  { 
    timezone: z.string().describe("The requested timezone in IANA format"),
  },
  async ({ timezone }) => {
    const time = new Date().toLocaleString("en-US", { timeZone: timezone });

    return {
      content: [{
        type: "text",
        text: time,
      }]
    };
  }
);

const transport = new StdioServerTransport();
await server.connect(transport);

Save the code above to a file named time-server.js in the mcptooling directory.

Run the server:​

Then, run the server using Node.js:

node time-server.js

What this server does​

This MCP server:

  • Creates a tool called "get-current-time"
  • Accepts a timezone parameter (in IANA format like "America/New_York")
  • Returns the current time in that timezone
  • Uses stdio transport (communicates via standard input/output)

Testing the server​

Since this uses stdio transport, you can test it by:

  • Running it and sending JSON-RPC messages via stdin
  • Or connecting it to an MCP client that supports stdio transport
  • Or using it with applications that integrate MCP servers (like Claude Desktop, if configured)
node time-server.js

Great! Your MCP server is now running successfully. Since there's no output shown, that means it's working correctly and waiting for MCP protocol messages on stdin.

Method 1: Test with a simple message​

You can type this JSON-RPC message (press Enter after pasting):

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

Result​

{"result":{"tools":[{"name":"get-current-time","description":"Get the current time for a requested timezone","inputSchema":{"type":"object","properties":{"timezone":{"type":"string","description":"The requested timezone in IANA format"}},"required":["timezone"],"additionalProperties":false,"$schema":"http://json-schema.org/draft-07/schema#"}}]},"jsonrpc":"2.0","id":1}

Method 2: Test the time tool​

You can test the "get-current-time" tool by sending a JSON-RPC message like this:

{"jsonrpc": "2.0", "id": 2, "method": "tools/call", "params": {"name": "get-current-time", "arguments": {"timezone": "America/New_York"}}}

You will receive a response with the current time in the specified timezone.

{"result":{"content":[{"type":"text","text":"5/31/2025, 10:29:05 PM"}]},"jsonrpc":"2.0","id":2}