Weather Tool MCP Server

This is a Spring Boot application acting as a Model Context Protocol (MCP) server that provides weather information using the WeatherAPI.

Example code from Book What you need to know about MCP servers - with Java and spring-boot examples By Peter Isberg URL: TODO

Features

• Weather Tool: Exposes a weather-tool that fetches current weather for a specified city.
• MCP Support: Implements the Model Context Protocol over SSE (Server-Sent Events) and HTTP.
• Endpoints:
  • GET /sse: SSE endpoint for MCP connection.
  • POST /sse: Endpoint for Streamable HTTP clients.
  • POST /message: Endpoint for handling JSON-RPC messages.

Prerequisites

• Java 21 or later
• Maven 3.6 or later
• A WeatherAPI API Key

Build Instructions

To build the application, run the following command in the project root:

mvn clean package

This will create an executable JAR file in the target/ directory (e.g., target/weather-tool-0.0.1-SNAPSHOT.jar).

Run Instructions

You can run the application using the Maven plugin:

mvn spring-boot:run

Or by running the built JAR file directly:

java -jar target/weather-tool-0.0.1-SNAPSHOT.jar

The server will start on port 8080 by default.

Usage

Tool Input Schema

The weather-tool accepts the following parameters:

• q (string, required): City name (e.g., "London").
• key (string, required): Your WeatherAPI key.

Example JSON-RPC Request

You can test the tool using a POST request to http://localhost:8080/message:

{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "name": "weather-tool",
    "arguments": {
      "q": "London",
      "key": "YOUR_API_KEY"
    }
  },
  "id": 1
}