MCP can be build with many languages and for this reason many SDKs are provided. In this course we will focus on the TypeScript MCP SDK and in this first lesson we will focus on the implementation of a Ping that is a general way to know from a computer if the other counterpart (our MCP server) is still responsive and able to keep the connection alive.

But even before we are able to send the Ping request, we have to create our own server and in order to create it we have to import McpServer from @modelcontextprotocol/sdk/server/mcp.js and instantiate it.

import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";

const server = new McpServer(serverInfo, options?)

This is not the exact code you’ll write, because we don’t know (yet) what serverInfo and options are. But if you’ll dig into the TS definitions you’ll soon discover that these are two objects that McpServer accepts to instantiate your server.

serverInfo

It a mandatory object that has the following shape:

type serverInfo = {
	name: string;
	title?: string;
	version: string;
}

So name and version are mandatory while title can be specified just for UI purposes.

options

While optional, this object allow us to specify important aspects of our server:

type options = {
	instructions?: string;
	capabilities?: ServerCapabilities;
}

• instructions is a simple description about how to use the server and its features
• capabilities instead allow us to list all the capabilities that the server supports (we will dig deeper later)

Now that we know the signature of McpServer we’re ready to create our server:

import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";

const server = new McpServer({
	name: 'epicme',
	version: '1.0.0'
}, {
	instructions: 'This lets you solve math problems.',
})

With a server in place, it’s time to think about how we will communicate with our clients. MCP servers offers two transport mechanism:

• stdio useful for command line tools and direct integrations (like when you have the server running locally).
• Streamable HTTP for remote servers able to handle clients request as well as server-to-client notifications.

For now, let’s stick with a simple stdio since our MCP server will run locally. It all begins importing StdioServerTransport.

import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";

Now that we have both the server and the transportation we need to connect the two together inside the main function present in the file:

async function main() {
	// Instantiate a transport
	const transport = new StdioServerTransport();
	// Let the server know what transport to use
	await server.connect(transport);
	
	// Once we have a transport, we can show some feedback
	console.error("The connection is in place");
}

We use the console.log especially in this case because we’re in stdio kind of communication, that already uses the console.log itself and can cause some confusion.

So now we’re connected with our MCP server and lucky us, the MCP Inspector is already able to make ping requests and we’re ready to move to the next lesson.