MCP & Copilot Studio Learning Project

# Weather Server Example This is an implementation of the weather server from the MCP quickstart guide, adapted for learning purposes. ## Implementation ```typescript import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js"; import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js"; import { z } from "zod"; const NWS_API_BASE = "https://api.weather.gov"; const USER_AGENT = "weather-app/1.0"; // Create server instance const server = new McpServer({ name: "weather", version: "1.0.0", capabilities: { resources: {}, tools: {}, }, }); // Helper function for making NWS API requests async function makeNWSRequest<T>(url: string): Promise<T | null> { const headers = { "User-Agent": USER_AGENT, Accept: "application/geo+json", }; try { const response = await fetch(url, { headers }); if (!response.ok) { throw new Error(`HTTP error! status: ${response.status}`); } return (await response.json()) as T; } catch (error) { console.error("Error making NWS request:", error); return null; } } // Register weather tools server.tool( "get-alerts", "Get weather alerts for a state", { state: z.string().length(2).describe("Two-letter state code (e.g. CA, NY)"), }, async ({ state }) => { const stateCode = state.toUpperCase(); const alertsUrl = `${NWS_API_BASE}/alerts?area=${stateCode}`; const alertsData = await makeNWSRequest<any>(alertsUrl); if (!alertsData) { return { content: [ { type: "text", text: "Failed to retrieve alerts data", }, ], }; } const features = alertsData.features || []; if (features.length === 0) { return { content: [ { type: "text", text: `No active alerts for ${stateCode}`, }, ], }; } const formattedAlerts = features.map((feature: any) => [ `Event: ${feature.properties.event || "Unknown"}`, `Area: ${feature.properties.areaDesc || "Unknown"}`, `Severity: ${feature.properties.severity || "Unknown"}`, `Status: ${feature.properties.status || "Unknown"}`, `Headline: ${feature.properties.headline || "No headline"}`, "---", ].join("\\n") ); const alertsText = `Active alerts for ${stateCode}:\\n\\n${formattedAlerts.join("\\n")}`; return { content: [ { type: "text", text: alertsText, }, ], }; }, ); server.tool( "get-forecast", "Get weather forecast for a location", { latitude: z.number().min(-90).max(90).describe("Latitude of the location"), longitude: z .number() .min(-180) .max(180) .describe("Longitude of the location"), }, async ({ latitude, longitude }) => { // Get grid point data const pointsUrl = `${NWS_API_BASE}/points/${latitude.toFixed(4)},${longitude.toFixed(4)}`; const pointsData = await makeNWSRequest<any>(pointsUrl); if (!pointsData) { return { content: [ { type: "text", text: `Failed to retrieve grid point data for coordinates: ${latitude}, ${longitude}. This location may not be supported by the NWS API (only US locations are supported).`, }, ], }; } const forecastUrl = pointsData.properties?.forecast; if (!forecastUrl) { return { content: [ { type: "text", text: "Failed to get forecast URL from grid point data", }, ], }; } // Get forecast data const forecastData = await makeNWSRequest<any>(forecastUrl); if (!forecastData) { return { content: [ { type: "text", text: "Failed to retrieve forecast data", }, ], }; } const periods = forecastData.properties?.periods || []; if (periods.length === 0) { return { content: [ { type: "text", text: "No forecast periods available", }, ], }; } // Format forecast periods const formattedForecast = periods.map((period: any) => [ `${period.name || "Unknown"}:`, `Temperature: ${period.temperature || "Unknown"}°${period.temperatureUnit || "F"}`, `Wind: ${period.windSpeed || "Unknown"} ${period.windDirection || ""}`, `${period.shortForecast || "No forecast available"}`, "---", ].join("\\n"), ); const forecastText = `Forecast for ${latitude}, ${longitude}:\\n\\n${formattedForecast.join("\\n")}`; return { content: [ { type: "text", text: forecastText, }, ], }; }, ); // Main function to run the server async function main() { const transport = new StdioServerTransport(); await server.connect(transport); console.error("Weather MCP Server running on stdio"); } main().catch((error) => { console.error("Fatal error in main():", error); process.exit(1); }); ``` ## Key Learning Points 1. **API Integration**: Shows how to integrate external APIs (National Weather Service) 2. **Error Handling**: Proper handling of API failures and edge cases 3. **Data Validation**: Using Zod for input validation 4. **Response Formatting**: Converting API responses to user-friendly text ## Usage Examples ### Get Weather Alerts ``` Tool: get-alerts Input: { "state": "CA" } ``` ### Get Weather Forecast ``` Tool: get-forecast Input: { "latitude": 37.7749, "longitude": -122.4194 } ``` ## Configuration for Claude Desktop Add to your `claude_desktop_config.json`: ```json { "mcpServers": { "weather": { "command": "node", "args": ["path/to/your/weather-server/build/index.js"] } } } ```