feat: add @aris/source-weatherkit package

Implements FeedSource for WeatherKit API. Depends on location source,
provides weather context for downstream sources, and produces weather
feed items.

Co-authored-by: Ona <no-reply@ona.com>

packages/aris-source-weatherkit/src/feed-items.ts

@@ -0,0 +1,97 @@
+import type { FeedItem } from "@aris/core"
+
+import type { Certainty, ConditionCode, PrecipitationType, Severity, Urgency } from "./weatherkit"
+
+export const WeatherFeedItemType = {
+	current: "weather-current",
+	hourly: "weather-hourly",
+	daily: "weather-daily",
+	alert: "weather-alert",
+} as const
+
+export type WeatherFeedItemType = (typeof WeatherFeedItemType)[keyof typeof WeatherFeedItemType]
+
+export type CurrentWeatherData = {
+	conditionCode: ConditionCode
+	daylight: boolean
+	humidity: number
+	precipitationIntensity: number
+	pressure: number
+	pressureTrend: "rising" | "falling" | "steady"
+	temperature: number
+	temperatureApparent: number
+	uvIndex: number
+	visibility: number
+	windDirection: number
+	windGust: number
+	windSpeed: number
+}
+
+export interface CurrentWeatherFeedItem extends FeedItem<
+	typeof WeatherFeedItemType.current,
+	CurrentWeatherData
+> {}
+
+export type HourlyWeatherData = {
+	forecastTime: Date
+	conditionCode: ConditionCode
+	daylight: boolean
+	humidity: number
+	precipitationAmount: number
+	precipitationChance: number
+	precipitationType: PrecipitationType
+	temperature: number
+	temperatureApparent: number
+	uvIndex: number
+	windDirection: number
+	windGust: number
+	windSpeed: number
+}
+
+export interface HourlyWeatherFeedItem extends FeedItem<
+	typeof WeatherFeedItemType.hourly,
+	HourlyWeatherData
+> {}
+
+export type DailyWeatherData = {
+	forecastDate: Date
+	conditionCode: ConditionCode
+	maxUvIndex: number
+	precipitationAmount: number
+	precipitationChance: number
+	precipitationType: PrecipitationType
+	snowfallAmount: number
+	sunrise: Date
+	sunset: Date
+	temperatureMax: number
+	temperatureMin: number
+}
+
+export interface DailyWeatherFeedItem extends FeedItem<
+	typeof WeatherFeedItemType.daily,
+	DailyWeatherData
+> {}
+
+export type WeatherAlertData = {
+	alertId: string
+	areaName: string
+	certainty: Certainty
+	description: string
+	detailsUrl: string
+	effectiveTime: Date
+	expireTime: Date
+	severity: Severity
+	source: string
+	urgency: Urgency
+}
+
+export interface WeatherAlertFeedItem extends FeedItem<
+	typeof WeatherFeedItemType.alert,
+	WeatherAlertData
+> {}
+
+export type WeatherFeedItem =
+	| CurrentWeatherFeedItem
+	| HourlyWeatherFeedItem
+	| DailyWeatherFeedItem
+	| WeatherAlertFeedItem

packages/aris-source-weatherkit/src/index.ts

@@ -0,0 +1,39 @@
+export { WeatherKey, type Weather } from "./weather-context"
+export {
+	WeatherSource,
+	Units,
+	type Units as UnitsType,
+	type WeatherSourceOptions,
+} from "./weather-source"
+
+export {
+	WeatherFeedItemType,
+	type WeatherFeedItemType as WeatherFeedItemTypeType,
+	type WeatherFeedItem,
+	type CurrentWeatherFeedItem,
+	type CurrentWeatherData,
+	type HourlyWeatherFeedItem,
+	type HourlyWeatherData,
+	type DailyWeatherFeedItem,
+	type DailyWeatherData,
+	type WeatherAlertFeedItem,
+	type WeatherAlertData,
+} from "./feed-items"
+
+export {
+	ConditionCode,
+	Severity,
+	Urgency,
+	Certainty,
+	PrecipitationType,
+	DefaultWeatherKitClient,
+	type ConditionCode as ConditionCodeType,
+	type Severity as SeverityType,
+	type Urgency as UrgencyType,
+	type Certainty as CertaintyType,
+	type PrecipitationType as PrecipitationTypeType,
+	type WeatherKitClient,
+	type WeatherKitCredentials,
+	type WeatherKitQueryOptions,
+	type WeatherKitResponse,
+} from "./weatherkit"

packages/aris-source-weatherkit/src/weather-context.ts

@@ -0,0 +1,27 @@
+import type { ContextKey } from "@aris/core"
+
+import { contextKey } from "@aris/core"
+
+import type { ConditionCode } from "./weatherkit"
+
+/**
+ * Simplified weather context for downstream sources.
+ */
+export interface Weather {
+	/** Current temperature */
+	temperature: number
+	/** Feels-like temperature */
+	temperatureApparent: number
+	/** Weather condition */
+	condition: ConditionCode
+	/** Relative humidity (0-1) */
+	humidity: number
+	/** UV index */
+	uvIndex: number
+	/** Wind speed */
+	windSpeed: number
+	/** Is it currently daytime */
+	daylight: boolean
+}
+
+export const WeatherKey: ContextKey<Weather> = contextKey("weather")

packages/aris-source-weatherkit/src/weather-source.test.ts

@@ -0,0 +1,182 @@
+import { contextValue, type Context } from "@aris/core"
+import { LocationKey } from "@aris/source-location"
+import { describe, expect, test } from "bun:test"
+
+import type { WeatherKitClient, WeatherKitResponse } from "./weatherkit"
+
+import fixture from "../fixtures/san-francisco.json"
+import { WeatherFeedItemType } from "./feed-items"
+import { WeatherKey } from "./weather-context"
+import { WeatherSource, Units } from "./weather-source"
+
+const mockCredentials = {
+	privateKey: "mock",
+	keyId: "mock",
+	teamId: "mock",
+	serviceId: "mock",
+}
+
+function createMockClient(response: WeatherKitResponse): WeatherKitClient {
+	return {
+		fetch: async () => response,
+	}
+}
+
+function createMockContext(location?: { lat: number; lng: number }): Context {
+	const ctx: Context = { time: new Date("2026-01-17T00:00:00Z") }
+	if (location) {
+		ctx[LocationKey] = { ...location, accuracy: 10, timestamp: new Date() }
+	}
+	return ctx
+}
+
+describe("WeatherSource", () => {
+	describe("properties", () => {
+		test("has correct id", () => {
+			const source = new WeatherSource({ credentials: mockCredentials })
+			expect(source.id).toBe("weather")
+		})
+
+		test("depends on location", () => {
+			const source = new WeatherSource({ credentials: mockCredentials })
+			expect(source.dependencies).toEqual(["location"])
+		})
+
+		test("throws error if neither client nor credentials provided", () => {
+			expect(() => new WeatherSource({} as never)).toThrow(
+				"Either client or credentials must be provided",
+			)
+		})
+	})
+
+	describe("fetchContext", () => {
+		const mockClient = createMockClient(fixture.response as WeatherKitResponse)
+
+		test("returns empty when no location", async () => {
+			const source = new WeatherSource({ client: mockClient })
+			const result = await source.fetchContext(createMockContext())
+
+			expect(result).toEqual({})
+		})
+
+		test("returns simplified weather context", async () => {
+			const source = new WeatherSource({ client: mockClient })
+			const context = createMockContext({ lat: 37.7749, lng: -122.4194 })
+
+			const result = await source.fetchContext(context)
+			const weather = contextValue(result, WeatherKey)
+
+			expect(weather).toBeDefined()
+			expect(typeof weather!.temperature).toBe("number")
+			expect(typeof weather!.temperatureApparent).toBe("number")
+			expect(typeof weather!.condition).toBe("string")
+			expect(typeof weather!.humidity).toBe("number")
+			expect(typeof weather!.uvIndex).toBe("number")
+			expect(typeof weather!.windSpeed).toBe("number")
+			expect(typeof weather!.daylight).toBe("boolean")
+		})
+
+		test("converts temperature to imperial", async () => {
+			const source = new WeatherSource({ client: mockClient, units: Units.imperial })
+			const context = createMockContext({ lat: 37.7749, lng: -122.4194 })
+
+			const result = await source.fetchContext(context)
+			const weather = contextValue(result, WeatherKey)
+
+			// Fixture has temperature around 10°C, imperial should be around 50°F
+			expect(weather!.temperature).toBeGreaterThan(40)
+		})
+	})
+
+	describe("fetchItems", () => {
+		const mockClient = createMockClient(fixture.response as WeatherKitResponse)
+
+		test("returns empty array when no location", async () => {
+			const source = new WeatherSource({ client: mockClient })
+			const items = await source.fetchItems(createMockContext())
+
+			expect(items).toEqual([])
+		})
+
+		test("returns feed items with all types", async () => {
+			const source = new WeatherSource({ client: mockClient })
+			const context = createMockContext({ lat: 37.7749, lng: -122.4194 })
+
+			const items = await source.fetchItems(context)
+
+			expect(items.length).toBeGreaterThan(0)
+			expect(items.some((i) => i.type === WeatherFeedItemType.current)).toBe(true)
+			expect(items.some((i) => i.type === WeatherFeedItemType.hourly)).toBe(true)
+			expect(items.some((i) => i.type === WeatherFeedItemType.daily)).toBe(true)
+		})
+
+		test("applies hourly and daily limits", async () => {
+			const source = new WeatherSource({
+				client: mockClient,
+				hourlyLimit: 3,
+				dailyLimit: 2,
+			})
+			const context = createMockContext({ lat: 37.7749, lng: -122.4194 })
+
+			const items = await source.fetchItems(context)
+
+			const hourlyItems = items.filter((i) => i.type === WeatherFeedItemType.hourly)
+			const dailyItems = items.filter((i) => i.type === WeatherFeedItemType.daily)
+
+			expect(hourlyItems.length).toBe(3)
+			expect(dailyItems.length).toBe(2)
+		})
+
+		test("sets timestamp from context.time", async () => {
+			const source = new WeatherSource({ client: mockClient })
+			const queryTime = new Date("2026-01-17T12:00:00Z")
+			const context = createMockContext({ lat: 37.7749, lng: -122.4194 })
+			context.time = queryTime
+
+			const items = await source.fetchItems(context)
+
+			for (const item of items) {
+				expect(item.timestamp).toEqual(queryTime)
+			}
+		})
+
+		test("assigns priority based on weather conditions", async () => {
+			const source = new WeatherSource({ client: mockClient })
+			const context = createMockContext({ lat: 37.7749, lng: -122.4194 })
+
+			const items = await source.fetchItems(context)
+
+			for (const item of items) {
+				expect(item.priority).toBeGreaterThanOrEqual(0)
+				expect(item.priority).toBeLessThanOrEqual(1)
+			}
+
+			const currentItem = items.find((i) => i.type === WeatherFeedItemType.current)
+			expect(currentItem).toBeDefined()
+			expect(currentItem!.priority).toBeGreaterThanOrEqual(0.5)
+		})
+
+		test("generates unique IDs for each item", async () => {
+			const source = new WeatherSource({ client: mockClient })
+			const context = createMockContext({ lat: 37.7749, lng: -122.4194 })
+
+			const items = await source.fetchItems(context)
+			const ids = items.map((i) => i.id)
+			const uniqueIds = new Set(ids)
+
+			expect(uniqueIds.size).toBe(ids.length)
+		})
+	})
+
+	describe("no reactive methods", () => {
+		test("does not implement onContextUpdate", () => {
+			const source = new WeatherSource({ credentials: mockCredentials })
+			expect(source.onContextUpdate).toBeUndefined()
+		})
+
+		test("does not implement onItemsUpdate", () => {
+			const source = new WeatherSource({ credentials: mockCredentials })
+			expect(source.onItemsUpdate).toBeUndefined()
+		})
+	})
+})

packages/aris-source-weatherkit/src/weather-source.ts

@@ -0,0 +1,363 @@
+import type { Context, FeedSource } from "@aris/core"
+
+import { contextValue } from "@aris/core"
+import { LocationKey } from "@aris/source-location"
+
+import { WeatherFeedItemType, type WeatherFeedItem } from "./feed-items"
+import { WeatherKey, type Weather } from "./weather-context"
+import {
+	DefaultWeatherKitClient,
+	type ConditionCode,
+	type CurrentWeather,
+	type DailyForecast,
+	type HourlyForecast,
+	type Severity,
+	type WeatherAlert,
+	type WeatherKitClient,
+	type WeatherKitCredentials,
+} from "./weatherkit"
+
+export const Units = {
+	metric: "metric",
+	imperial: "imperial",
+} as const
+
+export type Units = (typeof Units)[keyof typeof Units]
+
+export interface WeatherSourceOptions {
+	credentials?: WeatherKitCredentials
+	client?: WeatherKitClient
+	/** Number of hourly forecasts to include (default: 12) */
+	hourlyLimit?: number
+	/** Number of daily forecasts to include (default: 7) */
+	dailyLimit?: number
+	/** Units for temperature and measurements (default: metric) */
+	units?: Units
+}
+
+const DEFAULT_HOURLY_LIMIT = 12
+const DEFAULT_DAILY_LIMIT = 7
+
+const BASE_PRIORITY = {
+	current: 0.5,
+	hourly: 0.3,
+	daily: 0.2,
+	alert: 0.7,
+} as const
+
+const SEVERE_CONDITIONS = new Set<ConditionCode>([
+	"SevereThunderstorm",
+	"Hurricane",
+	"Tornado",
+	"TropicalStorm",
+	"Blizzard",
+	"FreezingRain",
+	"Hail",
+	"Frigid",
+	"Hot",
+])
+
+const MODERATE_CONDITIONS = new Set<ConditionCode>([
+	"Thunderstorm",
+	"IsolatedThunderstorms",
+	"ScatteredThunderstorms",
+	"HeavyRain",
+	"HeavySnow",
+	"FreezingDrizzle",
+	"BlowingSnow",
+])
+
+/**
+ * A FeedSource that provides weather context and feed items using Apple WeatherKit.
+ *
+ * Depends on location source for coordinates. Provides simplified weather context
+ * for downstream sources and produces weather feed items (current, hourly, daily, alerts).
+ *
+ * @example
+ * ```ts
+ * const weatherSource = new WeatherSource({
+ *   credentials: {
+ *     privateKey: process.env.WEATHERKIT_PRIVATE_KEY!,
+ *     keyId: process.env.WEATHERKIT_KEY_ID!,
+ *     teamId: process.env.WEATHERKIT_TEAM_ID!,
+ *     serviceId: process.env.WEATHERKIT_SERVICE_ID!,
+ *   },
+ *   units: Units.metric,
+ * })
+ *
+ * // Access weather context in downstream sources
+ * const weather = contextValue(context, WeatherKey)
+ * if (weather?.condition === "Rain") {
+ *   // suggest umbrella
+ * }
+ * ```
+ */
+export class WeatherSource implements FeedSource<WeatherFeedItem> {
+	readonly id = "weather"
+	readonly dependencies = ["location"]
+
+	private readonly client: WeatherKitClient
+	private readonly hourlyLimit: number
+	private readonly dailyLimit: number
+	private readonly units: Units
+
+	constructor(options: WeatherSourceOptions) {
+		if (!options.client && !options.credentials) {
+			throw new Error("Either client or credentials must be provided")
+		}
+		this.client = options.client ?? new DefaultWeatherKitClient(options.credentials!)
+		this.hourlyLimit = options.hourlyLimit ?? DEFAULT_HOURLY_LIMIT
+		this.dailyLimit = options.dailyLimit ?? DEFAULT_DAILY_LIMIT
+		this.units = options.units ?? Units.metric
+	}
+
+	async fetchContext(context: Context): Promise<Partial<Context>> {
+		const location = contextValue(context, LocationKey)
+		if (!location) {
+			return {}
+		}
+
+		const response = await this.client.fetch({
+			lat: location.lat,
+			lng: location.lng,
+		})
+
+		if (!response.currentWeather) {
+			return {}
+		}
+
+		const weather: Weather = {
+			temperature: convertTemperature(response.currentWeather.temperature, this.units),
+			temperatureApparent: convertTemperature(
+				response.currentWeather.temperatureApparent,
+				this.units,
+			),
+			condition: response.currentWeather.conditionCode,
+			humidity: response.currentWeather.humidity,
+			uvIndex: response.currentWeather.uvIndex,
+			windSpeed: convertSpeed(response.currentWeather.windSpeed, this.units),
+			daylight: response.currentWeather.daylight,
+		}
+
+		return { [WeatherKey]: weather }
+	}
+
+	async fetchItems(context: Context): Promise<WeatherFeedItem[]> {
+		const location = contextValue(context, LocationKey)
+		if (!location) {
+			return []
+		}
+
+		const timestamp = context.time
+
+		const response = await this.client.fetch({
+			lat: location.lat,
+			lng: location.lng,
+		})
+
+		const items: WeatherFeedItem[] = []
+
+		if (response.currentWeather) {
+			items.push(createCurrentWeatherFeedItem(response.currentWeather, timestamp, this.units))
+		}
+
+		if (response.forecastHourly?.hours) {
+			const hours = response.forecastHourly.hours.slice(0, this.hourlyLimit)
+			for (let i = 0; i < hours.length; i++) {
+				const hour = hours[i]
+				if (hour) {
+					items.push(createHourlyWeatherFeedItem(hour, i, timestamp, this.units))
+				}
+			}
+		}
+
+		if (response.forecastDaily?.days) {
+			const days = response.forecastDaily.days.slice(0, this.dailyLimit)
+			for (let i = 0; i < days.length; i++) {
+				const day = days[i]
+				if (day) {
+					items.push(createDailyWeatherFeedItem(day, i, timestamp, this.units))
+				}
+			}
+		}
+
+		if (response.weatherAlerts?.alerts) {
+			for (const alert of response.weatherAlerts.alerts) {
+				items.push(createWeatherAlertFeedItem(alert, timestamp))
+			}
+		}
+
+		return items
+	}
+}
+
+function adjustPriorityForCondition(basePriority: number, conditionCode: ConditionCode): number {
+	if (SEVERE_CONDITIONS.has(conditionCode)) {
+		return Math.min(1, basePriority + 0.3)
+	}
+	if (MODERATE_CONDITIONS.has(conditionCode)) {
+		return Math.min(1, basePriority + 0.15)
+	}
+	return basePriority
+}
+
+function adjustPriorityForAlertSeverity(severity: Severity): number {
+	switch (severity) {
+		case "extreme":
+			return 1
+		case "severe":
+			return 0.9
+		case "moderate":
+			return 0.75
+		case "minor":
+			return BASE_PRIORITY.alert
+	}
+}
+
+function convertTemperature(celsius: number, units: Units): number {
+	if (units === Units.imperial) {
+		return (celsius * 9) / 5 + 32
+	}
+	return celsius
+}
+
+function convertSpeed(kmh: number, units: Units): number {
+	if (units === Units.imperial) {
+		return kmh * 0.621371
+	}
+	return kmh
+}
+
+function convertDistance(km: number, units: Units): number {
+	if (units === Units.imperial) {
+		return km * 0.621371
+	}
+	return km
+}
+
+function convertPrecipitation(mm: number, units: Units): number {
+	if (units === Units.imperial) {
+		return mm * 0.0393701
+	}
+	return mm
+}
+
+function convertPressure(mb: number, units: Units): number {
+	if (units === Units.imperial) {
+		return mb * 0.02953
+	}
+	return mb
+}
+
+function createCurrentWeatherFeedItem(
+	current: CurrentWeather,
+	timestamp: Date,
+	units: Units,
+): WeatherFeedItem {
+	const priority = adjustPriorityForCondition(BASE_PRIORITY.current, current.conditionCode)
+
+	return {
+		id: `weather-current-${timestamp.getTime()}`,
+		type: WeatherFeedItemType.current,
+		priority,
+		timestamp,
+		data: {
+			conditionCode: current.conditionCode,
+			daylight: current.daylight,
+			humidity: current.humidity,
+			precipitationIntensity: convertPrecipitation(current.precipitationIntensity, units),
+			pressure: convertPressure(current.pressure, units),
+			pressureTrend: current.pressureTrend,
+			temperature: convertTemperature(current.temperature, units),
+			temperatureApparent: convertTemperature(current.temperatureApparent, units),
+			uvIndex: current.uvIndex,
+			visibility: convertDistance(current.visibility, units),
+			windDirection: current.windDirection,
+			windGust: convertSpeed(current.windGust, units),
+			windSpeed: convertSpeed(current.windSpeed, units),
+		},
+	}
+}
+
+function createHourlyWeatherFeedItem(
+	hourly: HourlyForecast,
+	index: number,
+	timestamp: Date,
+	units: Units,
+): WeatherFeedItem {
+	const priority = adjustPriorityForCondition(BASE_PRIORITY.hourly, hourly.conditionCode)
+
+	return {
+		id: `weather-hourly-${timestamp.getTime()}-${index}`,
+		type: WeatherFeedItemType.hourly,
+		priority,
+		timestamp,
+		data: {
+			forecastTime: new Date(hourly.forecastStart),
+			conditionCode: hourly.conditionCode,
+			daylight: hourly.daylight,
+			humidity: hourly.humidity,
+			precipitationAmount: convertPrecipitation(hourly.precipitationAmount, units),
+			precipitationChance: hourly.precipitationChance,
+			precipitationType: hourly.precipitationType,
+			temperature: convertTemperature(hourly.temperature, units),
+			temperatureApparent: convertTemperature(hourly.temperatureApparent, units),
+			uvIndex: hourly.uvIndex,
+			windDirection: hourly.windDirection,
+			windGust: convertSpeed(hourly.windGust, units),
+			windSpeed: convertSpeed(hourly.windSpeed, units),
+		},
+	}
+}
+
+function createDailyWeatherFeedItem(
+	daily: DailyForecast,
+	index: number,
+	timestamp: Date,
+	units: Units,
+): WeatherFeedItem {
+	const priority = adjustPriorityForCondition(BASE_PRIORITY.daily, daily.conditionCode)
+
+	return {
+		id: `weather-daily-${timestamp.getTime()}-${index}`,
+		type: WeatherFeedItemType.daily,
+		priority,
+		timestamp,
+		data: {
+			forecastDate: new Date(daily.forecastStart),
+			conditionCode: daily.conditionCode,
+			maxUvIndex: daily.maxUvIndex,
+			precipitationAmount: convertPrecipitation(daily.precipitationAmount, units),
+			precipitationChance: daily.precipitationChance,
+			precipitationType: daily.precipitationType,
+			snowfallAmount: convertPrecipitation(daily.snowfallAmount, units),
+			sunrise: new Date(daily.sunrise),
+			sunset: new Date(daily.sunset),
+			temperatureMax: convertTemperature(daily.temperatureMax, units),
+			temperatureMin: convertTemperature(daily.temperatureMin, units),
+		},
+	}
+}
+
+function createWeatherAlertFeedItem(alert: WeatherAlert, timestamp: Date): WeatherFeedItem {
+	const priority = adjustPriorityForAlertSeverity(alert.severity)
+
+	return {
+		id: `weather-alert-${alert.id}`,
+		type: WeatherFeedItemType.alert,
+		priority,
+		timestamp,
+		data: {
+			alertId: alert.id,
+			areaName: alert.areaName,
+			certainty: alert.certainty,
+			description: alert.description,
+			detailsUrl: alert.detailsUrl,
+			effectiveTime: new Date(alert.effectiveTime),
+			expireTime: new Date(alert.expireTime),
+			severity: alert.severity,
+			source: alert.source,
+			urgency: alert.urgency,
+		},
+	}
+}

packages/aris-source-weatherkit/src/weatherkit.ts

@@ -0,0 +1,367 @@
+// WeatherKit REST API client and response types
+// https://developer.apple.com/documentation/weatherkitrestapi
+
+import { type } from "arktype"
+
+export interface WeatherKitCredentials {
+	privateKey: string
+	keyId: string
+	teamId: string
+	serviceId: string
+}
+
+export interface WeatherKitQueryOptions {
+	lat: number
+	lng: number
+	language?: string
+	timezone?: string
+}
+
+export interface WeatherKitClient {
+	fetch(query: WeatherKitQueryOptions): Promise<WeatherKitResponse>
+}
+
+export class DefaultWeatherKitClient implements WeatherKitClient {
+	private readonly credentials: WeatherKitCredentials
+
+	constructor(credentials: WeatherKitCredentials) {
+		this.credentials = credentials
+	}
+
+	async fetch(query: WeatherKitQueryOptions): Promise<WeatherKitResponse> {
+		const token = await generateJwt(this.credentials)
+
+		const dataSets = ["currentWeather", "forecastHourly", "forecastDaily", "weatherAlerts"].join(
+			",",
+		)
+
+		const url = new URL(
+			`${WEATHERKIT_API_BASE}/weather/${query.language ?? "en"}/${query.lat}/${query.lng}`,
+		)
+		url.searchParams.set("dataSets", dataSets)
+		if (query.timezone) {
+			url.searchParams.set("timezone", query.timezone)
+		}
+
+		const response = await fetch(url.toString(), {
+			headers: {
+				Authorization: `Bearer ${token}`,
+			},
+		})
+
+		if (!response.ok) {
+			const body = await response.text()
+			throw new Error(`WeatherKit API error: ${response.status} ${response.statusText}: ${body}`)
+		}
+
+		const json = await response.json()
+		const result = weatherKitResponseSchema(json)
+
+		if (result instanceof type.errors) {
+			throw new Error(`WeatherKit API response validation failed: ${result.summary}`)
+		}
+
+		return result
+	}
+}
+
+export const Severity = {
+	Minor: "minor",
+	Moderate: "moderate",
+	Severe: "severe",
+	Extreme: "extreme",
+} as const
+
+export type Severity = (typeof Severity)[keyof typeof Severity]
+
+export const Urgency = {
+	Immediate: "immediate",
+	Expected: "expected",
+	Future: "future",
+	Past: "past",
+	Unknown: "unknown",
+} as const
+
+export type Urgency = (typeof Urgency)[keyof typeof Urgency]
+
+export const Certainty = {
+	Observed: "observed",
+	Likely: "likely",
+	Possible: "possible",
+	Unlikely: "unlikely",
+	Unknown: "unknown",
+} as const
+
+export type Certainty = (typeof Certainty)[keyof typeof Certainty]
+
+export const PrecipitationType = {
+	Clear: "clear",
+	Precipitation: "precipitation",
+	Rain: "rain",
+	Snow: "snow",
+	Sleet: "sleet",
+	Hail: "hail",
+	Mixed: "mixed",
+} as const
+
+export type PrecipitationType = (typeof PrecipitationType)[keyof typeof PrecipitationType]
+
+export const ConditionCode = {
+	Clear: "Clear",
+	Cloudy: "Cloudy",
+	Dust: "Dust",
+	Fog: "Fog",
+	Haze: "Haze",
+	MostlyClear: "MostlyClear",
+	MostlyCloudy: "MostlyCloudy",
+	PartlyCloudy: "PartlyCloudy",
+	ScatteredThunderstorms: "ScatteredThunderstorms",
+	Smoke: "Smoke",
+	Breezy: "Breezy",
+	Windy: "Windy",
+	Drizzle: "Drizzle",
+	HeavyRain: "HeavyRain",
+	Rain: "Rain",
+	Showers: "Showers",
+	Flurries: "Flurries",
+	HeavySnow: "HeavySnow",
+	MixedRainAndSleet: "MixedRainAndSleet",
+	MixedRainAndSnow: "MixedRainAndSnow",
+	MixedRainfall: "MixedRainfall",
+	MixedSnowAndSleet: "MixedSnowAndSleet",
+	ScatteredShowers: "ScatteredShowers",
+	ScatteredSnowShowers: "ScatteredSnowShowers",
+	Sleet: "Sleet",
+	Snow: "Snow",
+	SnowShowers: "SnowShowers",
+	Blizzard: "Blizzard",
+	BlowingSnow: "BlowingSnow",
+	FreezingDrizzle: "FreezingDrizzle",
+	FreezingRain: "FreezingRain",
+	Frigid: "Frigid",
+	Hail: "Hail",
+	Hot: "Hot",
+	Hurricane: "Hurricane",
+	IsolatedThunderstorms: "IsolatedThunderstorms",
+	SevereThunderstorm: "SevereThunderstorm",
+	Thunderstorm: "Thunderstorm",
+	Tornado: "Tornado",
+	TropicalStorm: "TropicalStorm",
+} as const
+
+export type ConditionCode = (typeof ConditionCode)[keyof typeof ConditionCode]
+
+const WEATHERKIT_API_BASE = "https://weatherkit.apple.com/api/v1"
+
+const severitySchema = type.enumerated(
+	Severity.Minor,
+	Severity.Moderate,
+	Severity.Severe,
+	Severity.Extreme,
+)
+
+const urgencySchema = type.enumerated(
+	Urgency.Immediate,
+	Urgency.Expected,
+	Urgency.Future,
+	Urgency.Past,
+	Urgency.Unknown,
+)
+
+const certaintySchema = type.enumerated(
+	Certainty.Observed,
+	Certainty.Likely,
+	Certainty.Possible,
+	Certainty.Unlikely,
+	Certainty.Unknown,
+)
+
+const precipitationTypeSchema = type.enumerated(
+	PrecipitationType.Clear,
+	PrecipitationType.Precipitation,
+	PrecipitationType.Rain,
+	PrecipitationType.Snow,
+	PrecipitationType.Sleet,
+	PrecipitationType.Hail,
+	PrecipitationType.Mixed,
+)
+
+const conditionCodeSchema = type.enumerated(...Object.values(ConditionCode))
+
+const pressureTrendSchema = type.enumerated("rising", "falling", "steady")
+
+const currentWeatherSchema = type({
+	asOf: "string",
+	conditionCode: conditionCodeSchema,
+	daylight: "boolean",
+	humidity: "number",
+	precipitationIntensity: "number",
+	pressure: "number",
+	pressureTrend: pressureTrendSchema,
+	temperature: "number",
+	temperatureApparent: "number",
+	temperatureDewPoint: "number",
+	uvIndex: "number",
+	visibility: "number",
+	windDirection: "number",
+	windGust: "number",
+	windSpeed: "number",
+})
+
+export type CurrentWeather = typeof currentWeatherSchema.infer
+
+const hourlyForecastSchema = type({
+	forecastStart: "string",
+	conditionCode: conditionCodeSchema,
+	daylight: "boolean",
+	humidity: "number",
+	precipitationAmount: "number",
+	precipitationChance: "number",
+	precipitationType: precipitationTypeSchema,
+	pressure: "number",
+	snowfallIntensity: "number",
+	temperature: "number",
+	temperatureApparent: "number",
+	temperatureDewPoint: "number",
+	uvIndex: "number",
+	visibility: "number",
+	windDirection: "number",
+	windGust: "number",
+	windSpeed: "number",
+})
+
+export type HourlyForecast = typeof hourlyForecastSchema.infer
+
+const dayWeatherConditionsSchema = type({
+	conditionCode: conditionCodeSchema,
+	humidity: "number",
+	precipitationAmount: "number",
+	precipitationChance: "number",
+	precipitationType: precipitationTypeSchema,
+	snowfallAmount: "number",
+	temperatureMax: "number",
+	temperatureMin: "number",
+	windDirection: "number",
+	"windGust?": "number",
+	windSpeed: "number",
+})
+
+export type DayWeatherConditions = typeof dayWeatherConditionsSchema.infer
+
+const dailyForecastSchema = type({
+	forecastStart: "string",
+	forecastEnd: "string",
+	conditionCode: conditionCodeSchema,
+	maxUvIndex: "number",
+	moonPhase: "string",
+	"moonrise?": "string",
+	"moonset?": "string",
+	precipitationAmount: "number",
+	precipitationChance: "number",
+	precipitationType: precipitationTypeSchema,
+	snowfallAmount: "number",
+	sunrise: "string",
+	sunriseCivil: "string",
+	sunriseNautical: "string",
+	sunriseAstronomical: "string",
+	sunset: "string",
+	sunsetCivil: "string",
+	sunsetNautical: "string",
+	sunsetAstronomical: "string",
+	temperatureMax: "number",
+	temperatureMin: "number",
+	"daytimeForecast?": dayWeatherConditionsSchema,
+	"overnightForecast?": dayWeatherConditionsSchema,
+})
+
+export type DailyForecast = typeof dailyForecastSchema.infer
+
+const weatherAlertSchema = type({
+	id: "string",
+	areaId: "string",
+	areaName: "string",
+	certainty: certaintySchema,
+	countryCode: "string",
+	description: "string",
+	detailsUrl: "string",
+	effectiveTime: "string",
+	expireTime: "string",
+	issuedTime: "string",
+	responses: "string[]",
+	severity: severitySchema,
+	source: "string",
+	urgency: urgencySchema,
+})
+
+export type WeatherAlert = typeof weatherAlertSchema.infer
+
+const weatherKitResponseSchema = type({
+	"currentWeather?": currentWeatherSchema,
+	"forecastHourly?": type({
+		hours: hourlyForecastSchema.array(),
+	}),
+	"forecastDaily?": type({
+		days: dailyForecastSchema.array(),
+	}),
+	"weatherAlerts?": type({
+		alerts: weatherAlertSchema.array(),
+	}),
+})
+
+export type WeatherKitResponse = typeof weatherKitResponseSchema.infer
+
+async function generateJwt(credentials: WeatherKitCredentials): Promise<string> {
+	const header = {
+		alg: "ES256",
+		kid: credentials.keyId,
+		id: `${credentials.teamId}.${credentials.serviceId}`,
+	}
+
+	const now = Math.floor(Date.now() / 1000)
+	const payload = {
+		iss: credentials.teamId,
+		iat: now,
+		exp: now + 3600,
+		sub: credentials.serviceId,
+	}
+
+	const encoder = new TextEncoder()
+	const headerB64 = btoa(JSON.stringify(header))
+		.replace(/\+/g, "-")
+		.replace(/\//g, "_")
+		.replace(/=+$/, "")
+	const payloadB64 = btoa(JSON.stringify(payload))
+		.replace(/\+/g, "-")
+		.replace(/\//g, "_")
+		.replace(/=+$/, "")
+
+	const signingInput = `${headerB64}.${payloadB64}`
+
+	const pemContents = credentials.privateKey
+		.replace(/-----BEGIN PRIVATE KEY-----/, "")
+		.replace(/-----END PRIVATE KEY-----/, "")
+		.replace(/\s/g, "")
+
+	const binaryKey = Uint8Array.from(atob(pemContents), (c) => c.charCodeAt(0))
+
+	const cryptoKey = await crypto.subtle.importKey(
+		"pkcs8",
+		binaryKey,
+		{ name: "ECDSA", namedCurve: "P-256" },
+		false,
+		["sign"],
+	)
+
+	const signature = await crypto.subtle.sign(
+		{ name: "ECDSA", hash: "SHA-256" },
+		cryptoKey,
+		encoder.encode(signingInput),
+	)
+
+	const signatureB64 = btoa(String.fromCharCode(...new Uint8Array(signature)))
+		.replace(/\+/g, "-")
+		.replace(/\//g, "_")
+		.replace(/=+$/, "")
+
+	return `${signingInput}.${signatureB64}`
+}