构建 MCP 服务器

# ❌ 错误（STDIO）
print("Processing request")

# ✅ 正确（STDIO）
import logging
logging.info("Processing request")

from typing import Any

import httpx
from mcp.server.fastmcp import FastMCP

# Initialize FastMCP server
mcp = FastMCP("weather")

# Constants
NWS_API_BASE = "https://api.weather.gov"
USER_AGENT = "weather-app/1.0"

async def make_nws_request(url: str) -> dict[str, Any] | None:
    """Make a request to the NWS API with proper error handling."""
    headers = {"User-Agent": USER_AGENT, "Accept": "application/geo+json"}
    async with httpx.AsyncClient() as client:
        try:
            response = await client.get(url, headers=headers, timeout=30.0)
            response.raise_for_status()
            return response.json()
        except Exception:
            return None


def format_alert(feature: dict) -> str:
    """Format an alert feature into a readable string."""
    props = feature["properties"]
    return f"""
Event: {props.get("event", "Unknown")}
Area: {props.get("areaDesc", "Unknown")}
Severity: {props.get("severity", "Unknown")}
Description: {props.get("description", "No description available")}
Instructions: {props.get("instruction", "No specific instructions provided")}
"""

@mcp.tool()
async def get_alerts(state: str) -> str:
    """获取美国州的天气警报。

    Args:
        state: 两位数的美国州代码（例如 CA、NY）
    """
    url = f"{NWS_API_BASE}/alerts/active/area/{state}"
    data = await make_nws_request(url)

    if not data or "features" not in data:
        return "Unable to fetch alerts or no alerts found."

    if not data["features"]:
        return "No active alerts for this state."

    alerts = [format_alert(feature) for feature in data["features"]]
    return "\n---\n".join(alerts)


@mcp.tool()
async def get_forecast(latitude: float, longitude: float) -> str:
    """Get weather forecast for a location.

    Args:
        latitude: Latitude of the location
        longitude: Longitude of the location
    """
    # First get the forecast grid endpoint
    points_url = f"{NWS_API_BASE}/points/{latitude},{longitude}"
    points_data = await make_nws_request(points_url)

    if not points_data:
        return "Unable to fetch forecast data for this location."

    # Get the forecast URL from the points response
    forecast_url = points_data["properties"]["forecast"]
    forecast_data = await make_nws_request(forecast_url)

    if not forecast_data:
        return "Unable to fetch detailed forecast."

    # Format the periods into a readable forecast
    periods = forecast_data["properties"]["periods"]
    forecasts = []
    for period in periods[:5]:  # Only show next 5 periods
        forecast = f"""
{period["name"]}:
Temperature: {period["temperature"]}°{period["temperatureUnit"]}
Wind: {period["windSpeed"]} {period["windDirection"]}
Forecast: {period["detailedForecast"]}
"""
        forecasts.append(forecast)

    return "\n---\n".join(forecasts)

def main():
    # Initialize and run the server
    mcp.run(transport="stdio")


if __name__ == "__main__":
    main()

// ❌ 错误（STDIO）
console.log("Server started");

// ✅ 正确（STDIO）
console.error("Server started"); // stderr 是安全的

node --version
npm --version

{
  "type": "module",
  "bin": {
    "weather": "./build/index.js"
  },
  "scripts": {
    "build": "tsc && chmod 755 build/index.js"
  },
  "files": ["build"]
}

{
  "compilerOptions": {
    "target": "ES2022",
    "module": "Node16",
    "moduleResolution": "Node16",
    "outDir": "./build",
    "rootDir": "./src",
    "strict": true,
    "esModuleInterop": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true
  },
  "include": ["src/**/*"],
  "exclude": ["node_modules"]
}

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",
});

// 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;
  }
}

interface AlertFeature {
  properties: {
    event?: string;
    areaDesc?: string;
    severity?: string;
    status?: string;
    headline?: string;
  };
}

// Format alert data
function formatAlert(feature: AlertFeature): string {
  const props = feature.properties;
  return [
    `Event: ${props.event || "Unknown"}`,
    `Area: ${props.areaDesc || "Unknown"}`,
    `Severity: ${props.severity || "Unknown"}`,
    `Status: ${props.status || "Unknown"}`,
    `Headline: ${props.headline || "No headline"}`,
    "---",
  ].join("\n");
}

interface ForecastPeriod {
  name?: string;
  temperature?: number;
  temperatureUnit?: string;
  windSpeed?: string;
  windDirection?: string;
  shortForecast?: string;
}

interface AlertsResponse {
  features: AlertFeature[];
}

interface PointsResponse {
  properties: {
    forecast?: string;
  };
}

interface ForecastResponse {
  properties: {
    periods: ForecastPeriod[];
  };
}

// Register weather tools

server.registerTool(
  "get_alerts",
  {
    description: "获取州的天气警报",
    inputSchema: {
      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<AlertsResponse>(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(formatAlert);
    const alertsText = `Active alerts for ${stateCode}:\n\n${formattedAlerts.join("\n")}`;

    return {
      content: [
        {
          type: "text",
          text: alertsText,
        },
      ],
    };
  },
);

server.registerTool(
  "get_forecast",
  {
    description: "Get weather forecast for a location",
    inputSchema: {
      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<PointsResponse>(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<ForecastResponse>(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: ForecastPeriod) =>
      [
        `${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,
        },
      ],
    };
  },
);

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);
});

@Service
public class WeatherService {

	private final RestClient restClient;

	public WeatherService() {
		this.restClient = RestClient.builder()
			.baseUrl("https://api.weather.gov")
			.defaultHeader("Accept", "application/geo+json")
			.defaultHeader("User-Agent", "WeatherApiClient/1.0 ([email protected])")
			.build();
	}

  @Tool(description = "Get weather forecast for a specific latitude/longitude")
  public String getWeatherForecastByLocation(
      double latitude,   // Latitude coordinate
      double longitude   // Longitude coordinate
  ) {
      // Returns detailed forecast including:
      // - Temperature and unit
      // - Wind speed and direction
      // - Detailed forecast description
  }

  @Tool(description = "Get weather alerts for a US state")
  public String getAlerts(
      @ToolParam(description = "Two-letter US state code (e.g. CA, NY)") String state
  ) {
      // Returns active alerts including:
      // - Event type
      // - Affected area
      // - Severity
      // - Description
      // - Safety instructions
  }

  // ......
}

@SpringBootApplication
public class McpServerApplication {

	public static void main(String[] args) {
		SpringApplication.run(McpServerApplication.class, args);
	}

	@Bean
	public ToolCallbackProvider weatherTools(WeatherService weatherService) {
		return  MethodToolCallbackProvider.builder().toolObjects(weatherService).build();
	}
}

./mvnw clean install

var stdioParams = ServerParameters.builder("java")
  .args("-jar", "/ABSOLUTE/PATH/TO/PARENT/FOLDER/mcp-weather-stdio-server-0.0.1-SNAPSHOT.jar")
  .build();

var stdioTransport = new StdioClientTransport(stdioParams);

var mcpClient = McpClient.sync(stdioTransport).build();

mcpClient.initialize();

ListToolsResult toolsList = mcpClient.listTools();

CallToolResult weather = mcpClient.callTool(
  new CallToolRequest("getWeatherForecastByLocation",
      Map.of("latitude", "47.6062", "longitude", "-122.3321")));

CallToolResult alert = mcpClient.callTool(
  new CallToolRequest("getAlerts", Map.of("state", "NY")));

mcpClient.closeGracefully();

<dependency>
    <groupId>org.springframework.ai</groupId>
    <artifactId>spring-ai-starter-mcp-client</artifactId>
</dependency>

spring.ai.mcp.client.stdio.servers-configuration=file:PATH/TO/claude_desktop_config.json

java --version

// Main function to run the MCP server
fun `run mcp server`() {
    // Create the MCP Server instance with a basic implementation
    val server = Server(
        Implementation(
            name = "weather", // Tool name is "weather"
            version = "1.0.0" // Version of the implementation
        ),
        ServerOptions(
            capabilities = ServerCapabilities(tools = ServerCapabilities.Tools(listChanged = true))
        )
    )

    // Create a transport using standard IO for server communication
    val transport = StdioServerTransport(
        System.`in`.asInput(),
        System.out.asSink().buffered()
    )

    runBlocking {
        server.connect(transport)
        val done = Job()
        server.onClose {
            done.complete()
        }
        done.join()
    }
}

// Extension function to fetch forecast information for given latitude and longitude
suspend fun HttpClient.getForecast(latitude: Double, longitude: Double): List<String> {
    val points = this.get("/points/$latitude,$longitude").body<Points>()
    val forecast = this.get(points.properties.forecast).body<Forecast>()
    return forecast.properties.periods.map { period ->
        """
            ${period.name}:
            Temperature: ${period.temperature} ${period.temperatureUnit}
            Wind: ${period.windSpeed} ${period.windDirection}
            Forecast: ${period.detailedForecast}
        """.trimIndent()
    }
}

// Extension function to fetch weather alerts for a given state
suspend fun HttpClient.getAlerts(state: String): List<String> {
    val alerts = this.get("/alerts/active/area/$state").body<Alert>()
    return alerts.features.map { feature ->
        """
            Event: ${feature.properties.event}
            Area: ${feature.properties.areaDesc}
            Severity: ${feature.properties.severity}
            Description: ${feature.properties.description}
            Instruction: ${feature.properties.instruction}
        """.trimIndent()
    }
}

@Serializable
data class Points(
    val properties: Properties
) {
    @Serializable
    data class Properties(val forecast: String)
}

@Serializable
data class Forecast(
    val properties: Properties
) {
    @Serializable
    data class Properties(val periods: List<Period>)

    @Serializable
    data class Period(
        val number: Int, val name: String, val startTime: String, val endTime: String,
        val isDaytime: Boolean, val temperature: Int, val temperatureUnit: String,
        val temperatureTrend: String, val probabilityOfPrecipitation: JsonObject,
        val windSpeed: String, val windDirection: String,
        val shortForecast: String, val detailedForecast: String,
    )
}

@Serializable
data class Alert(
    val features: List<Feature>
) {
    @Serializable
    data class Feature(
        val properties: Properties
    )

    @Serializable
    data class Properties(
        val event: String, val areaDesc: String, val severity: String,
        val description: String, val instruction: String?,
    )
}

// Create an HTTP client with a default request configuration and JSON content negotiation
val httpClient = HttpClient {
    defaultRequest {
        url("https://api.weather.gov")
        headers {
            append("Accept", "application/geo+json")
            append("User-Agent", "WeatherApiClient/1.0")
        }
        contentType(ContentType.Application.Json)
    }
    // Install content negotiation plugin for JSON serialization/deserialization
    install(ContentNegotiation) { json(Json { ignoreUnknownKeys = true }) }
}

// Register a tool to fetch weather alerts by state
server.addTool(
    name = "get_alerts",
    description = """
        Get weather alerts for a US state. Input is Two-letter US state code (e.g. CA, NY)
    """.trimIndent(),
    inputSchema = Tool.Input(
        properties = buildJsonObject {
            putJsonObject("state") {
                put("type", "string")
                put("description", "Two-letter US state code (e.g. CA, NY)")
            }
        },
        required = listOf("state")
    )
) { request ->
    val state = request.arguments["state"]?.jsonPrimitive?.content
    if (state == null) {
        return@addTool CallToolResult(
            content = listOf(TextContent("The 'state' parameter is required."))
        )
    }

    val alerts = httpClient.getAlerts(state)

    CallToolResult(content = alerts.map { TextContent(it) })
}

// Register a tool to fetch weather forecast by latitude and longitude
server.addTool(
    name = "get_forecast",
    description = """
        Get weather forecast for a specific latitude/longitude
    """.trimIndent(),
    inputSchema = Tool.Input(
        properties = buildJsonObject {
            putJsonObject("latitude") { put("type", "number") }
            putJsonObject("longitude") { put("type", "number") }
        },
        required = listOf("latitude", "longitude")
    )
) { request ->
    val latitude = request.arguments["latitude"]?.jsonPrimitive?.doubleOrNull
    val longitude = request.arguments["longitude"]?.jsonPrimitive?.doubleOrNull
    if (latitude == null || longitude == null) {
        return@addTool CallToolResult(
            content = listOf(TextContent("The 'latitude' and 'longitude' parameters are required."))
        )
    }

    val forecast = httpClient.getForecast(latitude, longitude)

    CallToolResult(content = forecast.map { TextContent(it) })
}

fun main() = `run mcp server`()

dotnet --version

# Add the Model Context Protocol SDK NuGet package
dotnet add package ModelContextProtocol --prerelease
# Add the .NET Hosting NuGet package
dotnet add package Microsoft.Extensions.Hosting

using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using ModelContextProtocol;
using System.Net.Http.Headers;

var builder = Host.CreateEmptyApplicationBuilder(settings: null);

builder.Services.AddMcpServer()
    .WithStdioServerTransport()
    .WithToolsFromAssembly();

builder.Services.AddSingleton(_ =>
{
    var client = new HttpClient() { BaseAddress = new Uri("https://api.weather.gov") };
    client.DefaultRequestHeaders.UserAgent.Add(new ProductInfoHeaderValue("weather-tool", "1.0"));
    return client;
});

var app = builder.Build();

await app.RunAsync();

using System.Text.Json;

internal static class HttpClientExt
{
    public static async Task<JsonDocument> ReadJsonDocumentAsync(this HttpClient client, string requestUri)
    {
        using var response = await client.GetAsync(requestUri);
        response.EnsureSuccessStatusCode();
        return await JsonDocument.ParseAsync(await response.Content.ReadAsStreamAsync());
    }
}

using ModelContextProtocol.Server;
using System.ComponentModel;
using System.Globalization;
using System.Text.Json;

namespace QuickstartWeatherServer.Tools;

[McpServerToolType]
public static class WeatherTools
{
    [McpServerTool, Description("Get weather alerts for a US state code.")]
    public static async Task<string> GetAlerts(
        HttpClient client,
        [Description("The US state code to get alerts for.")] string state)
    {
        using var jsonDocument = await client.ReadJsonDocumentAsync($"/alerts/active/area/{state}");
        var jsonElement = jsonDocument.RootElement;
        var alerts = jsonElement.GetProperty("features").EnumerateArray();

        if (!alerts.Any())
        {
            return "No active alerts for this state.";
        }

        return string.Join("\n--\n", alerts.Select(alert =>
        {
            JsonElement properties = alert.GetProperty("properties");
            return $"""
                    Event: {properties.GetProperty("event").GetString()}
                    Area: {properties.GetProperty("areaDesc").GetString()}
                    Severity: {properties.GetProperty("severity").GetString()}
                    Description: {properties.GetProperty("description").GetString()}
                    Instruction: {properties.GetProperty("instruction").GetString()}
                    """;
        }));
    }

    [McpServerTool, Description("Get weather forecast for a location.")]
    public static async Task<string> GetForecast(
        HttpClient client,
        [Description("Latitude of the location.")] double latitude,
        [Description("Longitude of the location.")] double longitude)
    {
        var pointUrl = string.Create(CultureInfo.InvariantCulture, $"/points/{latitude},{longitude}");
        using var jsonDocument = await client.ReadJsonDocumentAsync(pointUrl);
        var forecastUrl = jsonDocument.RootElement.GetProperty("properties").GetProperty("forecast").GetString()
            ?? throw new Exception($"No forecast URL provided by {client.BaseAddress}points/{latitude},{longitude}");

        using var forecastDocument = await client.ReadJsonDocumentAsync(forecastUrl);
        var periods = forecastDocument.RootElement.GetProperty("properties").GetProperty("periods").EnumerateArray();

        return string.Join("\n---\n", periods.Select(period => $"""
                {period.GetProperty("name").GetString()}
                Temperature: {period.GetProperty("temperature").GetInt32()}°F
                Wind: {period.GetProperty("windSpeed").GetString()} {period.GetProperty("windDirection").GetString()}
                Forecast: {period.GetProperty("detailedForecast").GetString()}
                """));
    }
}

dotnet run

// ❌ 错误（STDIO）
println!("Processing request");

// ✅ 正确（STDIO）
use tracing::info;
info!("Processing request"); // 写入 stderr

rustc --version
cargo --version

[package]
name = "weather"
version = "0.1.0"
edition = "2024"

[dependencies]
rmcp = { version = "0.3", features = ["server", "macros", "transport-io"] }
tokio = { version = "1.46", features = ["full"] }
reqwest = { version = "0.12", features = ["json"] }
serde = { version = "1.0", features = ["derive"] }
serde_json = "1.0"
anyhow = "1.0"
tracing = "0.1"
tracing-subscriber = { version = "0.3", features = ["env-filter", "std", "fmt"] }

use anyhow::Result;
use rmcp::{
    ServerHandler, ServiceExt,
    handler::server::{router::tool::ToolRouter, tool::Parameters},
    model::*,
    schemars, tool, tool_handler, tool_router,
};
use serde::Deserialize;
use serde::de::DeserializeOwned;

const NWS_API_BASE: &str = "https://api.weather.gov";
const USER_AGENT: &str = "weather-app/1.0";

#[derive(Debug, Deserialize)]
struct AlertsResponse {
    features: Vec<AlertFeature>,
}

#[derive(Debug, Deserialize)]
struct AlertFeature {
    properties: AlertProperties,
}

#[derive(Debug, Deserialize)]
struct AlertProperties {
    event: Option<String>,
    #[serde(rename = "areaDesc")]
    area_desc: Option<String>,
    severity: Option<String>,
    description: Option<String>,
    instruction: Option<String>,
}

#[derive(Debug, Deserialize)]
struct PointsResponse {
    properties: PointsProperties,
}

#[derive(Debug, Deserialize)]
struct PointsProperties {
    forecast: String,
}

#[derive(Debug, Deserialize)]
struct ForecastResponse {
    properties: ForecastProperties,
}

#[derive(Debug, Deserialize)]
struct ForecastProperties {
    periods: Vec<ForecastPeriod>,
}

#[derive(Debug, Deserialize)]
struct ForecastPeriod {
    name: String,
    temperature: i32,
    #[serde(rename = "temperatureUnit")]
    temperature_unit: String,
    #[serde(rename = "windSpeed")]
    wind_speed: String,
    #[serde(rename = "windDirection")]
    wind_direction: String,
    #[serde(rename = "detailedForecast")]
    detailed_forecast: String,
}

#[derive(serde::Deserialize, schemars::JsonSchema)]
pub struct MCPForecastRequest {
    latitude: f32,
    longitude: f32,
}

#[derive(serde::Deserialize, schemars::JsonSchema)]
pub struct MCPAlertRequest {
    state: String,
}

async fn make_nws_request<T: DeserializeOwned>(url: &str) -> Result<T> {
    let client = reqwest::Client::new();
    let rsp = client
        .get(url)
        .header(reqwest::header::USER_AGENT, USER_AGENT)
        .header(reqwest::header::ACCEPT, "application/geo+json")
        .send()
        .await?
        .error_for_status()?;
    Ok(rsp.json::<T>().await?)
}

fn format_alert(feature: &AlertFeature) -> String {
    let props = &feature.properties;
    format!(
        "Event: {}\nArea: {}\nSeverity: {}\nDescription: {}\nInstructions: {}",
        props.event.as_deref().unwrap_or("Unknown"),
        props.area_desc.as_deref().unwrap_or("Unknown"),
        props.severity.as_deref().unwrap_or("Unknown"),
        props
            .description
            .as_deref()
            .unwrap_or("No description available"),
        props
            .instruction
            .as_deref()
            .unwrap_or("No specific instructions provided")
    )
}

fn format_period(period: &ForecastPeriod) -> String {
    format!(
        "{}:\nTemperature: {}°{}\nWind: {} {}\nForecast: {}",
        period.name,
        period.temperature,
        period.temperature_unit,
        period.wind_speed,
        period.wind_direction,
        period.detailed_forecast
    )
}

pub struct Weather {
    tool_router: ToolRouter<Weather>,
}

#[tool_router]
impl Weather {
    fn new() -> Self {
        Self {
            tool_router: Self::tool_router(),
        }
    }

    #[tool(description = "Get weather alerts for a US state.")]
    async fn get_alerts(
        &self,
        Parameters(MCPAlertRequest { state }): Parameters<MCPAlertRequest>,
    ) -> String {
        let url = format!(
            "{}/alerts/active/area/{}",
            NWS_API_BASE,
            state.to_uppercase()
        );

        match make_nws_request::<AlertsResponse>(&url).await {
            Ok(data) => {
                if data.features.is_empty() {
                    "No active alerts for this state.".to_string()
                } else {
                    data.features
                        .iter()
                        .map(format_alert)
                        .collect::<Vec<_>>()
                        .join("\n---\n")
                }
            }
            Err(_) => "Unable to fetch alerts or no alerts found.".to_string(),
        }
    }

    #[tool(description = "Get weather forecast for a location.")]
    async fn get_forecast(
        &self,
        Parameters(MCPForecastRequest {
            latitude,
            longitude,
        }): Parameters<MCPForecastRequest>,
    ) -> String {
        let points_url = format!("{NWS_API_BASE}/points/{latitude},{longitude}");
        let Ok(points_data) = make_nws_request::<PointsResponse>(&points_url).await else {
            return "Unable to fetch forecast data for this location.".to_string();
        };

        let forecast_url = points_data.properties.forecast;

        let Ok(forecast_data) = make_nws_request::<ForecastResponse>(&forecast_url).await else {
            return "Unable to fetch forecast data for this location.".to_string();
        };

        let periods = &forecast_data.properties.periods;
        let forecast_summary: String = periods
            .iter()
            .take(5) // Next 5 periods only
            .map(format_period)
            .collect::<Vec<String>>()
            .join("\n---\n");
        forecast_summary
    }
}