Can I use Python instead of Node.js for MCP servers?

Yes. The official SDK has a Python equivalent. The protocol is language-agnostic as long as it adheres to the JSON-RPC 2.0 specification.

Why does Claude Desktop say the command was not found?

This almost always means the command path in claude_desktop_config.json is relative or incorrect. Always use absolute paths for local stdio servers.

Do I need to deploy anything to test a new tool?

No. Local stdio testing with the MCP Inspector is free and does not require any hosting; deploy only once the tool is ready for a team or production use.

getting-startedHowTo

MCP Server Quickstart Guide

Build, run, and connect your first Model Context Protocol server in Node.js and TypeScript in under five minutes.

Quick Answer / TL;DR

The fastest way to connect a local AI agent such as Claude Desktop or Cursor to a custom tool is the stdio transport in the official Model Context Protocol SDK: define a tool schema, register list and call handlers, then point the client config at the compiled server.

Key Takeaways

A minimal MCP server needs only a tool schema and two request handlers: list tools and call tool.
Validate every tool argument with a schema library such as Zod before executing it.
Test locally with the MCP Inspector before wiring the server into Claude Desktop or Cursor.

Prerequisites

Install Node.js 18 or higher, and have Claude Desktop or Cursor IDE available to test the finished server.

Basic familiarity with TypeScript and npm is enough to follow this guide end to end.

Initialize the project

Create a new directory, initialize a Node.js project, and install the official SDK along with Zod for input validation.

bash

mkdir my-first-mcp-server
cd my-first-mcp-server
npm init -y
npm install @modelcontextprotocol/sdk zod
npm install -D typescript @types/node
npx tsc --init

Define the tool server

A minimal server declares its name and capabilities, registers a list-tools handler that describes each tool's JSON Schema, and registers a call-tool handler that validates arguments with Zod before executing.

Always validate tool inputs with a schema library. The MCP SDK requires strict JSON Schema definitions for every tool to prevent malformed or malicious requests from reaching your execution logic.

typescript

import { Server } from "@modelcontextprotocol/sdk/server/index.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import { CallToolRequestSchema, ListToolsRequestSchema } from "@modelcontextprotocol/sdk/types.js";
import { z } from "zod";

const server = new Server(
  { name: "my-first-mcp-server", version: "1.0.0" },
  { capabilities: { tools: {} } }
);

const WeatherSchema = z.object({
  location: z.string().describe("The city and state, e.g., 'Mumbai, IN'"),
});

server.setRequestHandler(ListToolsRequestSchema, async () => ({
  tools: [
    {
      name: "get_current_weather",
      description: "Get the current weather for a specific location.",
      inputSchema: {
        type: "object",
        properties: { location: { type: "string", description: "The city and state" } },
        required: ["location"],
      },
    },
  ],
}));

server.setRequestHandler(CallToolRequestSchema, async (request) => {
  const { name, arguments: args } = request.params;
  if (name === "get_current_weather") {
    const parsed = WeatherSchema.parse(args);
    const mockWeather = { location: parsed.location, temperature: "28C", condition: "Partly Cloudy" };
    return { content: [{ type: "text", text: JSON.stringify(mockWeather, null, 2) }] };
  }
  throw new Error(`Tool ${name} not found`);
});

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

Compile, test, and connect to Claude Desktop

Compile the TypeScript output, then verify the server responds correctly with the MCP Inspector before wiring it into any client.

To use the server in Claude Desktop, add it to claude_desktop_config.json (in Library/Application Support/Claude on Mac, or %APPDATA%/Claude on Windows) using an absolute path to the compiled entry point, then restart Claude Desktop.

bash

npx tsc
npx @modelcontextprotocol/inspector node dist/index.js