How to build an MCP server

import { McpServer } from "@modelcontextprotocol/server";
import { serveStdio } from "@modelcontextprotocol/server/stdio";
import { z } from "zod";

function createServer() {
  const server = new McpServer({
    name: "account-lookup",
    version: "1.0.0",
  });

  server.registerTool(
    "lookup_account",
    {
      description: "Look up one account by id. Read only.",
      inputSchema: z.object({
        accountId: z.string().describe("Account id in your CRM"),
      }),
    },
    async ({ accountId }) => {
      const account = await lookupAccount(accountId);
      return {
        content: [{ type: "text", text: JSON.stringify(account) }],
      };
    },
  );

  return server;
}

await serveStdio(createServer);