Quickstart

Let's create a simple MCP server with a basic tool. This guide will walk you through creating a weather information tool.

Prerequisites

Make sure you have mcp-framework installed globally with npm:

npm i -g mcp-framework

Create a New Project

First, create a new MCP server project:

mcp create weather-mcp-server
cd weather-mcp-server

Add a Weather Tool

Use the CLI to create a new tool:

mcp add tool weather

This creates src/tools/WeatherTool.ts Let's modify it to handle weather requests:

import { MCPTool } from "mcp-framework";
import { z } from "zod";

interface WeatherInput {
  city: string;
}

class WeatherTool extends MCPTool<WeatherInput> {
  name = "weather";
  description = "Get weather information for a city";

  schema = {
    city: {
      type: z.string(),
      description: "City name to get weather for",
    },
  };

  async execute({ city }: WeatherInput) {
    // In a real scenario, this would call a weather API
    // For now, we return this sample data
    return {
      city,
      temperature: 22,
      condition: "Sunny",
      humidity: 45,
    };
  }
}

export default WeatherTool;

Build your project

# Build the project
npm run build

Choose a Transport

MCP Framework supports several types of transports:

1. STDIO Transport (Default): Perfect for CLI tools and local integrations. This is what we'll use with Claude Desktop.
2. HTTP Stream Transport: Recommended for web applications and services implementing the MCP 2025-03-26 specification.
3. SSE Transport (Deprecated): Legacy transport for older implementations.

For this quickstart, we'll use the default STDIO transport. To learn more about transports, check out:

• Transport Overview
• STDIO Transport
• HTTP Stream Transport (Recommended for web)
• SSE Transport (Deprecated)

Use the Tool

You can test your tool using the Claude Desktop client. Add this to your Claude Desktop config:

MacOS: ~/Library/Application Support/Claude/claude_desktop_config.json Windows: %APPDATA%/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "weather-mcp-server": {
      "command": "node",
      "args": ["/absolute/path/to/weather-mcp-server/dist/index.js"]
    }
  }
}

Now you can ask Claude to use your weather tool:

Could you check the weather in London using the weather tool?

What's Next?

The example above shows a basic tool implementation. In practice, you might want to:

1. Add real API integration
2. Include error handling
3. Add more weather-related tools
4. Create resources for caching
5. Define prompts for common queries
6. Consider using HTTP Stream transport for web integration

Check out our US Treasury Data Example for a more complete implementation.

Next Steps

• Learn more about Tools
• Learn about Resources
• Understand Prompts
• Explore Transports
• Set up Debugging