import { z } from "zod";
import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { makeNWSRequest, formatAlert } from "./weatherRequest.js";
import {
ForecastPeriod,
AlertsResponse,
PointsResponse,
ForecastResponse
} from "./weatherContracts.js";
export function registerWeatherTools(server: McpServer, NWS_API_BASE: string, USER_AGENT: string) {
// 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<AlertsResponse>(alertsUrl, USER_AGENT);
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.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<PointsResponse>(pointsUrl, USER_AGENT);
if (!pointsData) {
return {
content: [
{
type: "text",
text: `Failed to retrieve grid point data for coordinates: ${latitude}, ${longitude}. This location may not be supported by the NWS API (only US locations are supported).`,
},
],
};
}
const forecastUrl = pointsData.properties?.forecast;
if (!forecastUrl) {
return {
content: [
{
type: "text",
text: "Failed to get forecast URL from grid point data",
},
],
};
}
// Get forecast data
const forecastData = await makeNWSRequest<ForecastResponse>(forecastUrl, USER_AGENT);
if (!forecastData) {
return {
content: [
{
type: "text",
text: "Failed to retrieve forecast data",
},
],
};
}
const periods = forecastData.properties?.periods || [];
if (periods.length === 0) {
return {
content: [
{
type: "text",
text: "No forecast periods available",
},
],
};
}
// Format forecast periods
const formattedForecast = periods.map((period: ForecastPeriod) =>
[
`${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,
},
],
};
},
);
}
