feat(core): add sourceId to FeedItem

Each FeedSource implementation now sets sourceId on items
it produces, allowing consumers to trace items back to
their originating source.

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

apps/aelis-backend/src/engine/http.test.ts

@@ -64,6 +64,7 @@ describe("GET /api/feed", () => {
 		const items: FeedItem[] = [
 			{
 				id: "item-1",
+				sourceId: "test",
 				type: "test",
 				priority: 0.8,
 				timestamp: new Date("2025-01-01T00:00:00.000Z"),
@@ -96,6 +97,7 @@ describe("GET /api/feed", () => {
 		const items: FeedItem[] = [
 			{
 				id: "fresh-1",
+				sourceId: "test",
 				type: "test",
 				priority: 0.5,
 				timestamp: new Date("2025-06-01T12:00:00.000Z"),

apps/aelis-backend/src/enhancement/merge.test.ts

@@ -9,6 +9,7 @@ import { mergeEnhancement } from "./merge.ts"
 function makeItem(overrides: Partial<FeedItem> = {}): FeedItem {
 	return {
 		id: "item-1",
+		sourceId: "test",
 		type: "test",
 		timestamp: new Date("2025-01-01T00:00:00Z"),
 		data: { value: 42 },

apps/aelis-backend/src/enhancement/merge.ts

@@ -2,6 +2,8 @@ import type { FeedItem } from "@aelis/core"
 
 import type { EnhancementResult } from "./schema.ts"
 
+const ENHANCEMENT_SOURCE_ID = "aelis.enhancement"
+
 /**
  * Merges an EnhancementResult into feed items.
  *
@@ -10,7 +12,11 @@ import type { EnhancementResult } from "./schema.ts"
  * - Returns a new array (no mutation)
  * - Ignores fills for items/slots that don't exist
  */
-export function mergeEnhancement(items: FeedItem[], result: EnhancementResult, currentTime: Date): FeedItem[] {
+export function mergeEnhancement(
+	items: FeedItem[],
+	result: EnhancementResult,
+	currentTime: Date,
+): FeedItem[] {
 	const merged = items.map((item) => {
 		const fills = result.slotFills[item.id]
 		if (!fills || !item.slots) return item
@@ -31,6 +37,7 @@ export function mergeEnhancement(items: FeedItem[], result: EnhancementResult, c
 	for (const synthetic of result.syntheticItems) {
 		merged.push({
 			id: synthetic.id,
+			sourceId: ENHANCEMENT_SOURCE_ID,
 			type: synthetic.type,
 			timestamp: currentTime,
 			data: { text: synthetic.text },

apps/aelis-backend/src/enhancement/prompt-builder.test.ts

@@ -7,6 +7,7 @@ import { buildPrompt, hasUnfilledSlots } from "./prompt-builder.ts"
 function makeItem(overrides: Partial<FeedItem> = {}): FeedItem {
 	return {
 		id: "item-1",
+		sourceId: "test",
 		type: "test",
 		timestamp: new Date("2025-01-01T00:00:00Z"),
 		data: { value: 42 },
@@ -60,7 +61,9 @@ describe("buildPrompt", () => {
 
 		expect(parsed.items).toHaveLength(1)
 		expect((parsed.items as Array<Record<string, unknown>>)[0]!.id).toBe("item-1")
-		expect((parsed.items as Array<Record<string, unknown>>)[0]!.slots).toEqual({ insight: "Weather insight" })
+		expect((parsed.items as Array<Record<string, unknown>>)[0]!.slots).toEqual({
+			insight: "Weather insight",
+		})
 		expect((parsed.items as Array<Record<string, unknown>>)[0]!.type).toBeUndefined()
 		expect(parsed.context).toHaveLength(0)
 	})

apps/aelis-backend/src/session/user-session.test.ts

@@ -76,6 +76,7 @@ describe("UserSession.feed", () => {
 		const items: FeedItem[] = [
 			{
 				id: "item-1",
+				sourceId: "test",
 				type: "test",
 				timestamp: new Date("2025-01-01T00:00:00.000Z"),
 				data: { value: 42 },
@@ -93,6 +94,7 @@ describe("UserSession.feed", () => {
 		const items: FeedItem[] = [
 			{
 				id: "item-1",
+				sourceId: "test",
 				type: "test",
 				timestamp: new Date("2025-01-01T00:00:00.000Z"),
 				data: { value: 42 },
@@ -113,6 +115,7 @@ describe("UserSession.feed", () => {
 		const items: FeedItem[] = [
 			{
 				id: "item-1",
+				sourceId: "test",
 				type: "test",
 				timestamp: new Date("2025-01-01T00:00:00.000Z"),
 				data: { value: 42 },
@@ -139,6 +142,7 @@ describe("UserSession.feed", () => {
 		let currentItems: FeedItem[] = [
 			{
 				id: "item-1",
+				sourceId: "test",
 				type: "test",
 				timestamp: new Date("2025-01-01T00:00:00.000Z"),
 				data: { version: 1 },
@@ -169,6 +173,7 @@ describe("UserSession.feed", () => {
 		currentItems = [
 			{
 				id: "item-1",
+				sourceId: "test",
 				type: "test",
 				timestamp: new Date("2025-01-02T00:00:00.000Z"),
 				data: { version: 2 },
@@ -190,6 +195,7 @@ describe("UserSession.feed", () => {
 		const items: FeedItem[] = [
 			{
 				id: "item-1",
+				sourceId: "test",
 				type: "test",
 				timestamp: new Date("2025-01-01T00:00:00.000Z"),
 				data: { value: 42 },

packages/aelis-core/src/data-source.ts

@@ -17,6 +17,7 @@ import type { FeedItem } from "./feed"
  *     const data = await fetchWeather(location)
  *     return [{
  *       id: `weather-${Date.now()}`,
+ *       sourceId: "aelis.weather",
  *       type: this.type,
  *       timestamp: context.time,
  *       data: { temp: data.temperature },

packages/aelis-core/src/feed-engine.test.ts

@@ -99,6 +99,7 @@ function createWeatherSource(
 			return [
 				{
 					id: `weather-${Date.now()}`,
+					sourceId: "weather",
 					type: "weather",
 					timestamp: new Date(),
 					data: {
@@ -130,6 +131,7 @@ function createAlertSource(): FeedSource<AlertFeedItem> {
 				return [
 					{
 						id: "alert-storm",
+						sourceId: "alert",
 						type: "alert",
 						timestamp: new Date(),
 						data: { message: "Storm warning!" },
@@ -423,6 +425,7 @@ describe("FeedEngine", () => {
 					return [
 						{
 							id: "item-1",
+							sourceId: "working",
 							type: "test",
 							priority: 0.5,
 							timestamp: new Date(),
@@ -746,6 +749,7 @@ describe("FeedEngine", () => {
 					return [
 						{
 							id: "item-1",
+							sourceId: "reactive-items",
 							type: "test",
 							priority: 0.5,
 							timestamp: new Date(),
@@ -830,6 +834,7 @@ describe("FeedEngine", () => {
 					return [
 						{
 							id: `item-${fetchCount}`,
+							sourceId: "counter",
 							type: "test",
 							priority: 0.5,
 							timestamp: new Date(),
@@ -895,6 +900,7 @@ describe("FeedEngine", () => {
 					return [
 						{
 							id: `weather-${Date.now()}`,
+							sourceId: "weather",
 							type: "weather",
 							priority: 0.5,
 							timestamp: new Date(),

packages/aelis-core/src/feed-post-processor.test.ts

@@ -29,11 +29,17 @@ type WeatherItem = FeedItem<"weather", { temp: number }>
 type CalendarItem = FeedItem<"calendar", { title: string }>
 
 function weatherItem(id: string, temp: number): WeatherItem {
-	return { id, type: "weather", timestamp: new Date(), data: { temp } }
+	return { id, sourceId: "aelis.weather", type: "weather", timestamp: new Date(), data: { temp } }
 }
 
 function calendarItem(id: string, title: string): CalendarItem {
-	return { id, type: "calendar", timestamp: new Date(), data: { title } }
+	return {
+		id,
+		sourceId: "aelis.calendar",
+		type: "calendar",
+		timestamp: new Date(),
+		data: { title },
+	}
 }
 
 // =============================================================================

packages/aelis-core/src/feed-source.test.ts

@@ -98,6 +98,7 @@ function createWeatherSource(
 			return [
 				{
 					id: `weather-${Date.now()}`,
+					sourceId: "weather",
 					type: "weather",
 					timestamp: new Date(),
 					data: {
@@ -129,6 +130,7 @@ function createAlertSource(): FeedSource<AlertFeedItem> {
 				return [
 					{
 						id: "alert-storm",
+						sourceId: "alert",
 						type: "alert",
 						timestamp: new Date(),
 						data: { message: "Storm warning!" },

packages/aelis-core/src/feed.test.ts

@@ -6,6 +6,7 @@ describe("FeedItem slots", () => {
 	test("FeedItem without slots is valid", () => {
 		const item: FeedItem<"test", { value: number }> = {
 			id: "test-1",
+			sourceId: "test-source",
 			type: "test",
 			timestamp: new Date(),
 			data: { value: 42 },
@@ -17,6 +18,7 @@ describe("FeedItem slots", () => {
 	test("FeedItem with unfilled slots", () => {
 		const item: FeedItem<"weather", { temp: number }> = {
 			id: "weather-1",
+			sourceId: "aelis.weather",
 			type: "weather",
 			timestamp: new Date(),
 			data: { temp: 18 },
@@ -41,6 +43,7 @@ describe("FeedItem slots", () => {
 	test("FeedItem with filled slots", () => {
 		const item: FeedItem<"weather", { temp: number }> = {
 			id: "weather-1",
+			sourceId: "aelis.weather",
 			type: "weather",
 			timestamp: new Date(),
 			data: { temp: 18 },
@@ -75,6 +78,7 @@ describe("FeedItem slots", () => {
 	test("FeedItem with empty slots record", () => {
 		const item: FeedItem<"test", { value: number }> = {
 			id: "test-1",
+			sourceId: "test-source",
 			type: "test",
 			timestamp: new Date(),
 			data: { value: 1 },

packages/aelis-core/src/feed.ts

@@ -48,6 +48,7 @@ export interface Slot {
  *
  * const item: WeatherItem = {
  *   id: "weather-123",
+ *   sourceId: "aelis.weatherkit",
  *   type: "weather",
  *   timestamp: new Date(),
  *   data: { temp: 18, condition: "cloudy" },
@@ -67,6 +68,8 @@ export interface FeedItem<
 > {
 	/** Unique identifier */
 	id: string
+	/** ID of the FeedSource that produced this item */
+	sourceId: string
 	/** Item type, matches the data source type */
 	type: TType
 	/** When this item was generated */

packages/aelis-data-source-weatherkit/src/data-source.ts

@@ -47,6 +47,8 @@ interface LocationData {
 
 const LocationKey: ContextKey<LocationData> = contextKey("aelis.location", "location")
 
+const SOURCE_ID = "aelis.weather"
+
 export class WeatherKitDataSource implements DataSource<WeatherFeedItem, WeatherKitQueryConfig> {
 	private readonly DEFAULT_HOURLY_LIMIT = 12
 	private readonly DEFAULT_DAILY_LIMIT = 7
@@ -236,6 +238,7 @@ function createCurrentWeatherFeedItem(
 
 	return {
 		id: `weather-current-${timestamp.getTime()}`,
+		sourceId: SOURCE_ID,
 		type: WeatherFeedItemType.Current,
 		timestamp,
 		data: {
@@ -270,6 +273,7 @@ function createHourlyWeatherFeedItem(
 
 	return {
 		id: `weather-hourly-${timestamp.getTime()}-${index}`,
+		sourceId: SOURCE_ID,
 		type: WeatherFeedItemType.Hourly,
 		timestamp,
 		data: {
@@ -304,6 +308,7 @@ function createDailyWeatherFeedItem(
 
 	return {
 		id: `weather-daily-${timestamp.getTime()}-${index}`,
+		sourceId: SOURCE_ID,
 		type: WeatherFeedItemType.Daily,
 		timestamp,
 		data: {
@@ -331,6 +336,7 @@ function createWeatherAlertFeedItem(alert: WeatherAlert, timestamp: Date): Weath
 
 	return {
 		id: `weather-alert-${alert.id}`,
+		sourceId: SOURCE_ID,
 		type: WeatherFeedItemType.Alert,
 		timestamp,
 		data: {

packages/aelis-feed-enhancers/src/time-of-day-enhancer.test.ts

@@ -40,6 +40,7 @@ function saturday(hour: number, minute = 0): Date {
 function weatherCurrent(id = "w-current"): FeedItem {
 	return {
 		id,
+		sourceId: "aelis.weather",
 		type: WeatherFeedItemType.Current,
 		timestamp: new Date(),
 		data: { temperature: 18, precipitationIntensity: 0 },
@@ -49,6 +50,7 @@ function weatherCurrent(id = "w-current"): FeedItem {
 function weatherCurrentRainy(id = "w-current-rain"): FeedItem {
 	return {
 		id,
+		sourceId: "aelis.weather",
 		type: WeatherFeedItemType.Current,
 		timestamp: new Date(),
 		data: { temperature: 12, precipitationIntensity: 2.5 },
@@ -58,6 +60,7 @@ function weatherCurrentRainy(id = "w-current-rain"): FeedItem {
 function weatherCurrentExtreme(id = "w-current-extreme"): FeedItem {
 	return {
 		id,
+		sourceId: "aelis.weather",
 		type: WeatherFeedItemType.Current,
 		timestamp: new Date(),
 		data: { temperature: -5, precipitationIntensity: 0 },
@@ -67,6 +70,7 @@ function weatherCurrentExtreme(id = "w-current-extreme"): FeedItem {
 function weatherHourly(id = "w-hourly"): FeedItem {
 	return {
 		id,
+		sourceId: "aelis.weather",
 		type: WeatherFeedItemType.Hourly,
 		timestamp: new Date(),
 		data: { forecastTime: new Date(), temperature: 20 },
@@ -76,6 +80,7 @@ function weatherHourly(id = "w-hourly"): FeedItem {
 function weatherDaily(id = "w-daily"): FeedItem {
 	return {
 		id,
+		sourceId: "aelis.weather",
 		type: WeatherFeedItemType.Daily,
 		timestamp: new Date(),
 		data: { forecastDate: new Date() },
@@ -85,6 +90,7 @@ function weatherDaily(id = "w-daily"): FeedItem {
 function weatherAlert(id = "w-alert", urgency = 0.9): FeedItem {
 	return {
 		id,
+		sourceId: "aelis.weather",
 		type: WeatherFeedItemType.Alert,
 		timestamp: new Date(),
 		data: { severity: "extreme" },
@@ -99,6 +105,7 @@ function calendarEvent(
 ): FeedItem {
 	return {
 		id,
+		sourceId: "aelis.google-calendar",
 		type: CalendarFeedItemType.Event,
 		timestamp: new Date(),
 		data: {
@@ -120,6 +127,7 @@ function calendarEvent(
 function calendarAllDay(id: string): FeedItem {
 	return {
 		id,
+		sourceId: "aelis.google-calendar",
 		type: CalendarFeedItemType.AllDay,
 		timestamp: new Date(),
 		data: {
@@ -145,6 +153,7 @@ function caldavEvent(
 ): FeedItem {
 	return {
 		id,
+		sourceId: "aelis.caldav",
 		type: CalDavFeedItemType.Event,
 		timestamp: new Date(),
 		data: {
@@ -170,6 +179,7 @@ function caldavEvent(
 function tflAlert(id = "tfl-1", urgency = 0.8): FeedItem {
 	return {
 		id,
+		sourceId: "aelis.tfl",
 		type: TflFeedItemType.Alert,
 		timestamp: new Date(),
 		data: {
@@ -185,6 +195,7 @@ function tflAlert(id = "tfl-1", urgency = 0.8): FeedItem {
 function unknownItem(id = "unknown-1"): FeedItem {
 	return {
 		id,
+		sourceId: "unknown",
 		type: "some-future-type",
 		timestamp: new Date(),
 		data: { foo: "bar" },

packages/aelis-source-caldav/src/caldav-source.ts

@@ -133,7 +133,7 @@ export class CalDavSource implements FeedSource<CalDavFeedItem> {
 	async fetchItems(context: Context): Promise<CalDavFeedItem[]> {
 		const now = context.time
 		const events = await this.fetchEvents(context)
-		return events.map((event) => createFeedItem(event, now, this.timeZone))
+		return events.map((event) => createFeedItem(event, now, this.id, this.timeZone))
 	}
 
 	private fetchEvents(context: Context): Promise<CalDavEventData[]> {
@@ -351,9 +351,15 @@ function createEventSlots(): Record<string, Slot> {
 	}
 }
 
-function createFeedItem(event: CalDavEventData, now: Date, timeZone?: string): CalDavFeedItem {
+function createFeedItem(
+	event: CalDavEventData,
+	now: Date,
+	sourceId: string,
+	timeZone?: string,
+): CalDavFeedItem {
 	return {
 		id: `caldav-event-${event.uid}${event.recurrenceId ? `-${event.recurrenceId}` : ""}`,
+		sourceId,
 		type: CalDavFeedItemType.Event,
 		timestamp: now,
 		data: event,

packages/aelis-source-google-calendar/src/google-calendar-source.ts

@@ -113,7 +113,7 @@ export class GoogleCalendarSource implements FeedSource<CalendarFeedItem> {
 		const now = context.time.getTime()
 		const lookaheadMs = this.lookaheadHours * 60 * 60 * 1000
 
-		return events.map((event) => createFeedItem(event, now, lookaheadMs))
+		return events.map((event) => createFeedItem(event, now, lookaheadMs, this.id))
 	}
 
 	private async resolveCalendarIds(): Promise<string[]> {
@@ -208,11 +208,13 @@ function createFeedItem(
 	event: CalendarEventData,
 	nowMs: number,
 	lookaheadMs: number,
+	sourceId: string,
 ): CalendarFeedItem {
 	const itemType = event.isAllDay ? CalendarFeedItemType.AllDay : CalendarFeedItemType.Event
 
 	return {
 		id: `calendar-${event.calendarId}-${event.eventId}`,
+		sourceId,
 		type: itemType,
 		timestamp: new Date(nowMs),
 		data: event,

packages/aelis-source-tfl/src/tfl-source.ts

@@ -151,6 +151,7 @@ export class TflSource implements FeedSource<TflAlertFeedItem> {
 
 			return {
 				id: `tfl-alert-${status.lineId}-${status.severity}`,
+				sourceId: this.id,
 				type: TflFeedItemType.Alert,
 				timestamp: context.time,
 				data,

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

@@ -167,7 +167,9 @@ export class WeatherSource implements FeedSource<WeatherFeedItem> {
 		const items: WeatherFeedItem[] = []
 
 		if (response.currentWeather) {
-			items.push(createCurrentWeatherFeedItem(response.currentWeather, timestamp, this.units))
+			items.push(
+				createCurrentWeatherFeedItem(response.currentWeather, timestamp, this.units, this.id),
+			)
 		}
 
 		if (response.forecastHourly?.hours) {
@@ -175,7 +177,7 @@ export class WeatherSource implements FeedSource<WeatherFeedItem> {
 			for (let i = 0; i < hours.length; i++) {
 				const hour = hours[i]
 				if (hour) {
-					items.push(createHourlyWeatherFeedItem(hour, i, timestamp, this.units))
+					items.push(createHourlyWeatherFeedItem(hour, i, timestamp, this.units, this.id))
 				}
 			}
 		}
@@ -185,14 +187,14 @@ export class WeatherSource implements FeedSource<WeatherFeedItem> {
 			for (let i = 0; i < days.length; i++) {
 				const day = days[i]
 				if (day) {
-					items.push(createDailyWeatherFeedItem(day, i, timestamp, this.units))
+					items.push(createDailyWeatherFeedItem(day, i, timestamp, this.units, this.id))
 				}
 			}
 		}
 
 		if (response.weatherAlerts?.alerts) {
 			for (const alert of response.weatherAlerts.alerts) {
-				items.push(createWeatherAlertFeedItem(alert, timestamp))
+				items.push(createWeatherAlertFeedItem(alert, timestamp, this.id))
 			}
 		}
 
@@ -284,6 +286,7 @@ function createCurrentWeatherFeedItem(
 	current: CurrentWeather,
 	timestamp: Date,
 	units: Units,
+	sourceId: string,
 ): WeatherFeedItem {
 	const signals: FeedItemSignals = {
 		urgency: adjustUrgencyForCondition(BASE_URGENCY.current, current.conditionCode),
@@ -292,6 +295,7 @@ function createCurrentWeatherFeedItem(
 
 	return {
 		id: `weather-current-${timestamp.getTime()}`,
+		sourceId,
 		type: WeatherFeedItemType.Current,
 		timestamp,
 		data: {
@@ -324,6 +328,7 @@ function createHourlyWeatherFeedItem(
 	index: number,
 	timestamp: Date,
 	units: Units,
+	sourceId: string,
 ): WeatherFeedItem {
 	const signals: FeedItemSignals = {
 		urgency: adjustUrgencyForCondition(BASE_URGENCY.hourly, hourly.conditionCode),
@@ -332,6 +337,7 @@ function createHourlyWeatherFeedItem(
 
 	return {
 		id: `weather-hourly-${timestamp.getTime()}-${index}`,
+		sourceId,
 		type: WeatherFeedItemType.Hourly,
 		timestamp,
 		data: {
@@ -358,6 +364,7 @@ function createDailyWeatherFeedItem(
 	index: number,
 	timestamp: Date,
 	units: Units,
+	sourceId: string,
 ): WeatherFeedItem {
 	const signals: FeedItemSignals = {
 		urgency: adjustUrgencyForCondition(BASE_URGENCY.daily, daily.conditionCode),
@@ -366,6 +373,7 @@ function createDailyWeatherFeedItem(
 
 	return {
 		id: `weather-daily-${timestamp.getTime()}-${index}`,
+		sourceId,
 		type: WeatherFeedItemType.Daily,
 		timestamp,
 		data: {
@@ -385,7 +393,11 @@ function createDailyWeatherFeedItem(
 	}
 }
 
-function createWeatherAlertFeedItem(alert: WeatherAlert, timestamp: Date): WeatherFeedItem {
+function createWeatherAlertFeedItem(
+	alert: WeatherAlert,
+	timestamp: Date,
+	sourceId: string,
+): WeatherFeedItem {
 	const signals: FeedItemSignals = {
 		urgency: adjustUrgencyForAlertSeverity(alert.severity),
 		timeRelevance: timeRelevanceForAlertSeverity(alert.severity),
@@ -393,6 +405,7 @@ function createWeatherAlertFeedItem(alert: WeatherAlert, timestamp: Date): Weath
 
 	return {
 		id: `weather-alert-${alert.id}`,
+		sourceId,
 		type: WeatherFeedItemType.Alert,
 		timestamp,
 		data: {