服务器开发

from typing import Any
import httpx
from mcp.server.fastmcp import FastMCP
 
# 初始化FastMCP服务器
mcp = FastMCP("weather")
 
# 常量
NWS_API_BASE = "https://api.weather.gov"
USER_AGENT = "weather-app/1.0"

async def make_nws_request(url: str) -> dict[str, Any] | None:
    """向NWS API发送请求并进行适当的错误处理。"""
    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:
    """将警报特征格式化为可读字符串。"""
    props = feature["properties"]
    return f"""
Event: {props.get('event', 'Unknown')}  # 事件类型
Area: {props.get('areaDesc', 'Unknown')}  # 影响区域
Severity: {props.get('severity', 'Unknown')}  # 严重程度
Description: {props.get('description', 'No description available')}  # 详细描述
Instructions: {props.get('instruction', 'No specific instructions provided')}  # 安全指南
"""

@mcp.tool()
async def get_alerts(state: str) -> str:
    """获取美国各州的天气警报。
    
    Args:
        state: 美国州的两字母代码（例如CA代表加利福尼亚州, NY代表纽约州）
    """
    url = f"{NWS_API_BASE}/alerts/active/area/{state}"
    data = await make_nws_request(url)
 
    if not data or "features" not in data:
        return "无法获取警报信息或未找到相关警报。"
 
    if not data["features"]:
        return "该州目前没有活跃的天气警报。"
 
    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:
    """获取指定位置的天气预报。
    
    Args:
        latitude: 位置的纬度
        longitude: 位置的经度
    """
    # 首先获取预报网格端点
    points_url = f"{NWS_API_BASE}/points/{latitude},{longitude}"
    points_data = await make_nws_request(points_url)
 
    if not points_data:
        return "无法为该位置获取预报数据。"
 
    # 从点响应中获取预报URL
    forecast_url = points_data["properties"]["forecast"]
    forecast_data = await make_nws_request(forecast_url)
 
    if not forecast_data:
        return "无法获取详细预报。"
 
    # 将时段格式化为可读的预报
    periods = forecast_data["properties"]["periods"]
    forecasts = []
    for period in periods[:5]:  # 只显示接下来的5个时段
        forecast = f"""
{period['name']}:  # 时段名称（如：今晚、明天）
Temperature: {period['temperature']}°{period['temperatureUnit']}  # 温度和单位
Wind: {period['windSpeed']} {period['windDirection']}  # 风速和风向
Forecast: {period['detailedForecast']}  # 详细天气情况
"""
        forecasts.append(forecast)
 
    return "\n---\n".join(forecasts)

if __name__ == "__main__":
    # 初始化并运行服务器
    mcp.run(transport='stdio')