feat(core): add Slot type and slots field to FeedItem

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

.claude/skills/gpg-commit-signing/SKILL.md

@@ -0,0 +1,43 @@
+---
+name: gpg-commit-signing
+description: Sign git commits with GPG in non-interactive environments. Use when committing code and the `GPG_PRIVATE_KEY_PASSPHRASE` environment variable is available. Triggers on "commit", "sign commit", "GPG", "git commit -S", or any git operation requiring signed commits.
+---
+
+# GPG Commit Signing
+
+Sign commits in headless/non-interactive environments where `/dev/tty` is unavailable.
+
+## Workflow
+
+1. Check whether `GPG_PRIVATE_KEY_PASSPHRASE` is set:
+
+   ```bash
+   test -n "$GPG_PRIVATE_KEY_PASSPHRASE" && echo "available" || echo "not set"
+   ```
+
+   If not set, skip signing — commit without `-S`.
+
+2. Try a direct signed commit first — the environment may already have loopback pinentry configured:
+
+   ```bash
+   git commit -S -m "message"
+   ```
+
+   If this succeeds, no further steps are needed.
+
+3. If step 2 fails with a `/dev/tty` error, use `--pinentry-mode loopback` via a wrapper script:
+
+   ```bash
+   printf '#!/bin/sh\ngpg --batch --pinentry-mode loopback --passphrase "$GPG_PRIVATE_KEY_PASSPHRASE" "$@"\n' > /tmp/gpg-sign.sh
+   chmod +x /tmp/gpg-sign.sh
+   git -c gpg.program=/tmp/gpg-sign.sh commit -S -m "message"
+   rm /tmp/gpg-sign.sh
+   ```
+
+   This passes the passphrase directly to gpg on each signing invocation, bypassing the need for a configured gpg-agent.
+
+## Anti-patterns
+
+- Do not echo or log `GPG_PRIVATE_KEY_PASSPHRASE`.
+- Do not commit without `-S` when the passphrase is available — the project expects signed commits.
+- Do not leave wrapper scripts on disk after committing.

apps/aris-backend/src/feed/http.test.ts

@@ -1,4 +1,4 @@
-import type { ActionDefinition, Context, FeedItem, FeedSource } from "@aris/core"
+import type { ActionDefinition, ContextEntry, FeedItem, FeedSource } from "@aris/core"
 
 import { describe, expect, test } from "bun:test"
 import { Hono } from "hono"
@@ -27,7 +27,7 @@ function createStubSource(id: string, items: FeedItem[] = []): FeedSource {
 		async executeAction(): Promise<unknown> {
 			return undefined
 		},
-		async fetchContext(): Promise<Partial<Context> | null> {
+		async fetchContext(): Promise<readonly ContextEntry[] | null> {
 			return null
 		},
 		async fetchItems() {

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

@@ -1,4 +1,4 @@
-import type { ActionDefinition, Context, FeedSource } from "@aris/core"
+import type { ActionDefinition, ContextEntry, FeedSource } from "@aris/core"
 
 import { LocationSource } from "@aris/source-location"
 import { describe, expect, test } from "bun:test"
@@ -14,7 +14,7 @@ function createStubSource(id: string): FeedSource {
 		async executeAction(): Promise<unknown> {
 			return undefined
 		},
-		async fetchContext(): Promise<Partial<Context> | null> {
+		async fetchContext(): Promise<readonly ContextEntry[] | null> {
 			return null
 		},
 		async fetchItems() {

bun.lock

@@ -89,6 +89,17 @@
         "arktype": "^2.1.0",
       },
     },
+    "packages/aris-feed-enhancers": {
+      "name": "@aris/feed-enhancers",
+      "version": "0.0.0",
+      "dependencies": {
+        "@aris/core": "workspace:*",
+        "@aris/source-caldav": "workspace:*",
+        "@aris/source-google-calendar": "workspace:*",
+        "@aris/source-tfl": "workspace:*",
+        "@aris/source-weatherkit": "workspace:*",
+      },
+    },
     "packages/aris-source-caldav": {
       "name": "@aris/source-caldav",
       "version": "0.0.0",
@@ -144,6 +155,8 @@
 
     "@aris/data-source-weatherkit": ["@aris/data-source-weatherkit@workspace:packages/aris-data-source-weatherkit"],
 
+    "@aris/feed-enhancers": ["@aris/feed-enhancers@workspace:packages/aris-feed-enhancers"],
+
     "@aris/source-caldav": ["@aris/source-caldav@workspace:packages/aris-source-caldav"],
 
     "@aris/source-google-calendar": ["@aris/source-google-calendar@workspace:packages/aris-source-google-calendar"],

packages/aris-core/src/context-bridge.ts

@@ -1,8 +1,10 @@
-import type { Context } from "./context"
+import type { ContextEntry } from "./context"
 import type { ContextProvider } from "./context-provider"
 
+import { contextKey } from "./context"
+
 interface ContextUpdatable {
-	pushContextUpdate(update: Partial<Context>): void
+	pushContextUpdate(entries: readonly ContextEntry[]): void
 }
 
 export interface ProviderError {
@@ -54,7 +56,7 @@ export class ContextBridge {
 		this.providers.set(provider.key, provider as ContextProvider)
 
 		const cleanup = provider.onUpdate((value) => {
-			this.controller.pushContextUpdate({ [provider.key]: value })
+			this.controller.pushContextUpdate([[contextKey(provider.key), value]])
 		})
 		this.cleanups.push(cleanup)
 
@@ -67,7 +69,7 @@ export class ContextBridge {
 	 * Returns errors from providers that failed to fetch.
 	 */
 	async refresh(): Promise<RefreshResult> {
-		const updates: Partial<Context> = {}
+		const collected: ContextEntry[] = []
 		const errors: ProviderError[] = []
 
 		const entries = Array.from(this.providers.entries())
@@ -78,7 +80,7 @@ export class ContextBridge {
 		entries.forEach(([key], i) => {
 			const result = results[i]
 			if (result?.status === "fulfilled") {
-				updates[key] = result.value
+				collected.push([contextKey(key), result.value])
 			} else if (result?.status === "rejected") {
 				errors.push({
 					key,
@@ -87,7 +89,7 @@ export class ContextBridge {
 			}
 		})
 
-		this.controller.pushContextUpdate(updates)
+		this.controller.pushContextUpdate(collected)
 
 		return { errors }
 	}

packages/aris-core/src/context.test.ts

@@ -0,0 +1,184 @@
+import { describe, expect, test } from "bun:test"
+
+import type { ContextKey } from "./context"
+
+import { Context, contextKey } from "./context"
+
+interface Weather {
+	temperature: number
+}
+
+interface NextEvent {
+	title: string
+}
+
+const WeatherKey: ContextKey<Weather> = contextKey("aris.weather", "current")
+const NextEventKey: ContextKey<NextEvent> = contextKey("aris.google-calendar", "nextEvent")
+
+describe("Context", () => {
+	describe("get", () => {
+		test("returns undefined for missing key", () => {
+			const ctx = new Context()
+			expect(ctx.get(WeatherKey)).toBeUndefined()
+		})
+
+		test("returns value for exact key match", () => {
+			const ctx = new Context()
+			const weather: Weather = { temperature: 20 }
+			ctx.set([[WeatherKey, weather]])
+
+			expect(ctx.get(WeatherKey)).toEqual(weather)
+		})
+
+		test("distinguishes keys with different parts", () => {
+			const ctx = new Context()
+			ctx.set([
+				[WeatherKey, { temperature: 20 }],
+				[NextEventKey, { title: "Standup" }],
+			])
+
+			expect(ctx.get(WeatherKey)).toEqual({ temperature: 20 })
+			expect(ctx.get(NextEventKey)).toEqual({ title: "Standup" })
+		})
+
+		test("last write wins for same key", () => {
+			const ctx = new Context()
+			ctx.set([[WeatherKey, { temperature: 20 }]])
+			ctx.set([[WeatherKey, { temperature: 25 }]])
+
+			expect(ctx.get(WeatherKey)).toEqual({ temperature: 25 })
+		})
+	})
+
+	describe("find", () => {
+		test("returns empty array when no keys match", () => {
+			const ctx = new Context()
+			expect(ctx.find(WeatherKey)).toEqual([])
+		})
+
+		test("returns exact match as single result", () => {
+			const ctx = new Context()
+			ctx.set([[NextEventKey, { title: "Standup" }]])
+
+			const results = ctx.find(NextEventKey)
+			expect(results).toHaveLength(1)
+			expect(results[0]!.value).toEqual({ title: "Standup" })
+		})
+
+		test("prefix match returns multiple instances", () => {
+			const workKey = contextKey<NextEvent>("aris.google-calendar", "nextEvent", {
+				account: "work",
+			})
+			const personalKey = contextKey<NextEvent>("aris.google-calendar", "nextEvent", {
+				account: "personal",
+			})
+
+			const ctx = new Context()
+			ctx.set([
+				[workKey, { title: "Sprint Planning" }],
+				[personalKey, { title: "Dentist" }],
+			])
+
+			const prefix = contextKey<NextEvent>("aris.google-calendar", "nextEvent")
+			const results = ctx.find(prefix)
+
+			expect(results).toHaveLength(2)
+			const titles = results.map((r) => r.value.title).sort()
+			expect(titles).toEqual(["Dentist", "Sprint Planning"])
+		})
+
+		test("prefix match includes exact match and longer keys", () => {
+			const baseKey = contextKey<NextEvent>("aris.google-calendar", "nextEvent")
+			const instanceKey = contextKey<NextEvent>("aris.google-calendar", "nextEvent", {
+				account: "work",
+			})
+
+			const ctx = new Context()
+			ctx.set([
+				[baseKey, { title: "Base" }],
+				[instanceKey, { title: "Instance" }],
+			])
+
+			const results = ctx.find(baseKey)
+			expect(results).toHaveLength(2)
+		})
+
+		test("does not match keys that share a string prefix but differ at segment boundary", () => {
+			const keyA = contextKey<string>("aris.calendar", "next")
+			const keyB = contextKey<string>("aris.calendar", "nextEvent")
+
+			const ctx = new Context()
+			ctx.set([
+				[keyA, "a"],
+				[keyB, "b"],
+			])
+
+			const results = ctx.find(keyA)
+			expect(results).toHaveLength(1)
+			expect(results[0]!.value).toBe("a")
+		})
+
+		test("object key parts with different property order match", () => {
+			const key1 = contextKey<string>("source", "ctx", { b: 2, a: 1 })
+			const key2 = contextKey<string>("source", "ctx", { a: 1, b: 2 })
+
+			const ctx = new Context()
+			ctx.set([[key1, "value"]])
+
+			// Exact match via get should work regardless of property order
+			expect(ctx.get(key2)).toBe("value")
+
+			// find with the reordered key as prefix should also match
+			const prefix = contextKey<string>("source", "ctx")
+			const results = ctx.find(prefix)
+			expect(results).toHaveLength(1)
+		})
+
+		test("single-segment prefix matches all keys starting with that segment", () => {
+			const ctx = new Context()
+			ctx.set([
+				[contextKey("aris.weather", "current"), { temperature: 20 }],
+				[contextKey("aris.weather", "forecast"), { high: 25 }],
+				[contextKey("aris.calendar", "nextEvent"), { title: "Meeting" }],
+			])
+
+			const results = ctx.find(contextKey("aris.weather"))
+			expect(results).toHaveLength(2)
+		})
+
+		test("does not match shorter keys", () => {
+			const ctx = new Context()
+			ctx.set([[contextKey("aris.weather"), "short"]])
+
+			const results = ctx.find(contextKey("aris.weather", "current"))
+			expect(results).toHaveLength(0)
+		})
+
+		test("numeric key parts match correctly", () => {
+			const ctx = new Context()
+			ctx.set([
+				[contextKey("source", 1, "data"), "one"],
+				[contextKey("source", 2, "data"), "two"],
+			])
+
+			const results = ctx.find(contextKey("source", 1))
+			expect(results).toHaveLength(1)
+			expect(results[0]!.value).toBe("one")
+		})
+	})
+
+	describe("size", () => {
+		test("returns 0 for empty context", () => {
+			expect(new Context().size).toBe(0)
+		})
+
+		test("reflects number of entries", () => {
+			const ctx = new Context()
+			ctx.set([
+				[WeatherKey, { temperature: 20 }],
+				[NextEventKey, { title: "Standup" }],
+			])
+			expect(ctx.size).toBe(2)
+		})
+	})
+})

packages/aris-core/src/context.ts

@@ -1,46 +1,131 @@
 /**
- * Branded type for type-safe context keys.
+ * Tuple-keyed context system inspired by React Query's query keys.
  *
- * Each package defines its own keys with associated value types:
- * ```ts
- * const LocationKey: ContextKey<Location> = contextKey("location")
- * ```
+ * Context keys are arrays that form a hierarchy. Sources write to specific
+ * keys (e.g., ["aris.google-calendar", "nextEvent", { account: "work" }])
+ * and consumers can query by exact match or prefix match to get all values
+ * of a given type across source instances.
  */
-export type ContextKey<T> = string & { __contextValue?: T }
 
-/**
- * Creates a typed context key.
- *
- * @example
- * ```ts
- * interface Location { lat: number; lng: number; accuracy: number }
- * const LocationKey: ContextKey<Location> = contextKey("location")
- * ```
- */
-export function contextKey<T>(key: string): ContextKey<T> {
-	return key as ContextKey<T>
+// -- Key types --
+
+/** A single segment of a context key: string, number, or a record of primitives. */
+export type ContextKeyPart = string | number | Record<string, unknown>
+
+/** A context key is a readonly tuple of parts, branded with the value type. */
+export type ContextKey<T> = readonly ContextKeyPart[] & { __contextValue?: T }
+
+/** Creates a typed context key. */
+export function contextKey<T>(...parts: ContextKeyPart[]): ContextKey<T> {
+	return parts as ContextKey<T>
 }
 
-/**
- * Type-safe accessor for context values.
- *
- * @example
- * ```ts
- * const location = contextValue(context, LocationKey)
- * if (location) {
- *   console.log(location.lat, location.lng)
- * }
- * ```
- */
-export function contextValue<T>(context: Context, key: ContextKey<T>): T | undefined {
-	return context[key] as T | undefined
-}
+// -- Serialization --
 
 /**
- * Arbitrary key-value bag representing the current state.
- * Always includes `time`. Other keys are added by context providers.
+ * Deterministic serialization of a context key for use as a Map key.
+ * Object parts have their keys sorted for stable comparison.
  */
-export interface Context {
+export function serializeKey(key: readonly ContextKeyPart[]): string {
+	return JSON.stringify(key, (_key, value) => {
+		if (value !== null && typeof value === "object" && !Array.isArray(value)) {
+			const sorted: Record<string, unknown> = {}
+			for (const k of Object.keys(value).sort()) {
+				sorted[k] = value[k]
+			}
+			return sorted
+		}
+		return value
+	})
+}
+
+// -- Key matching --
+
+/** Returns true if `key` starts with all parts of `prefix`. */
+function keyStartsWith(key: readonly ContextKeyPart[], prefix: readonly ContextKeyPart[]): boolean {
+	if (key.length < prefix.length) return false
+
+	for (let i = 0; i < prefix.length; i++) {
+		if (!partsEqual(key[i]!, prefix[i]!)) return false
+	}
+
+	return true
+}
+
+/** Recursive structural equality, matching React Query's partialMatchKey approach. */
+function partsEqual(a: unknown, b: unknown): boolean {
+	if (a === b) return true
+	if (typeof a !== typeof b) return false
+	if (a && b && typeof a === "object" && typeof b === "object") {
+		const aKeys = Object.keys(a)
+		const bKeys = Object.keys(b)
+		if (aKeys.length !== bKeys.length) return false
+		return aKeys.every((key) =>
+			partsEqual(
+				(a as Record<string, unknown>)[key],
+				(b as Record<string, unknown>)[key],
+			),
+		)
+	}
+	return false
+}
+
+// -- Context store --
+
+/** A single context entry: a key-value pair. */
+export type ContextEntry<T = unknown> = readonly [ContextKey<T>, T]
+
+/**
+ * Mutable context store with tuple keys.
+ *
+ * Supports exact-match lookups and prefix-match queries.
+ * Sources write context in topological order during refresh.
+ */
+export class Context {
 	time: Date
-	[key: string]: unknown
+	private readonly store: Map<string, { key: readonly ContextKeyPart[]; value: unknown }>
+
+	constructor(time: Date = new Date()) {
+		this.time = time
+		this.store = new Map()
+	}
+
+	/** Merges entries into this context. */
+	set(entries: readonly ContextEntry[]): void {
+		for (const [key, value] of entries) {
+			this.store.set(serializeKey(key), { key, value })
+		}
+	}
+
+	/** Exact-match lookup. Returns the value for the given key, or undefined. */
+	get<T>(key: ContextKey<T>): T | undefined {
+		const entry = this.store.get(serializeKey(key))
+		return entry?.value as T | undefined
+	}
+
+	/**
+	 * Prefix-match query. Returns all entries whose key starts with the given prefix.
+	 *
+	 * @example
+	 * ```ts
+	 * // Get all "nextEvent" values across calendar source instances
+	 * const events = context.find(contextKey("nextEvent"))
+	 * ```
+	 */
+	find<T>(prefix: ContextKey<T>): Array<{ key: readonly ContextKeyPart[]; value: T }> {
+		const results: Array<{ key: readonly ContextKeyPart[]; value: T }> = []
+
+		for (const entry of this.store.values()) {
+			if (keyStartsWith(entry.key, prefix)) {
+				results.push({ key: entry.key, value: entry.value as T })
+			}
+		}
+
+		return results
+	}
+
+	/** Returns the number of entries (excluding time). */
+	get size(): number {
+		return this.store.size
+	}
 }

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

@@ -12,7 +12,7 @@ import type { FeedItem } from "./feed"
  *   readonly type = "weather"
  *
  *   async query(context: Context): Promise<WeatherItem[]> {
- *     const location = contextValue(context, LocationKey)
+ *     const location = context.get(LocationKey)
  *     if (!location) return []
  *     const data = await fetchWeather(location)
  *     return [{

packages/aris-core/src/feed-controller.ts

@@ -1,8 +1,9 @@
-import type { Context } from "./context"
+import type { ContextEntry } from "./context"
 import type { DataSource } from "./data-source"
 import type { FeedItem } from "./feed"
 import type { ReconcileResult } from "./reconciler"
 
+import { Context } from "./context"
 import { Reconciler } from "./reconciler"
 
 export interface FeedControllerConfig {
@@ -40,7 +41,7 @@ const DEFAULT_DEBOUNCE_MS = 100
  * })
  *
  * // Context update triggers debounced reconcile
- * controller.pushContextUpdate({ [LocationKey]: location })
+ * controller.pushContextUpdate([[LocationKey, location]])
  *
  * // Direct reconcile (no debounce)
  * const result = await controller.reconcile()
@@ -59,7 +60,7 @@ export class FeedController<TItems extends FeedItem = never> {
 	private stopped = false
 
 	constructor(config?: FeedControllerConfig) {
-		this.context = config?.initialContext ?? { time: new Date() }
+		this.context = config?.initialContext ?? new Context()
 		this.debounceMs = config?.debounceMs ?? DEFAULT_DEBOUNCE_MS
 		this.timeout = config?.timeout
 	}
@@ -94,9 +95,10 @@ export class FeedController<TItems extends FeedItem = never> {
 		}
 	}
 
-	/** Merges update into context and schedules a debounced reconcile. */
-	pushContextUpdate(update: Partial<Context>): void {
-		this.context = { ...this.context, ...update, time: new Date() }
+	/** Merges entries into context and schedules a debounced reconcile. */
+	pushContextUpdate(entries: readonly ContextEntry[]): void {
+		this.context.time = new Date()
+		this.context.set(entries)
 		this.scheduleReconcile()
 	}
 

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

@@ -1,9 +1,9 @@
 import { describe, expect, test } from "bun:test"
 
-import type { ActionDefinition, Context, ContextKey, FeedItem, FeedSource } from "./index"
+import type { ActionDefinition, ContextEntry, ContextKey, FeedItem, FeedSource } from "./index"
 
 import { FeedEngine } from "./feed-engine"
-import { TimeRelevance, UnknownActionError, contextKey, contextValue } from "./index"
+import { Context, TimeRelevance, UnknownActionError, contextKey } from "./index"
 
 // No-op action methods for test sources
 const noActions = {
@@ -48,7 +48,7 @@ interface SimulatedLocationSource extends FeedSource {
 }
 
 function createLocationSource(): SimulatedLocationSource {
-	let callback: ((update: Partial<Context>) => void) | null = null
+	let callback: ((entries: readonly ContextEntry[]) => void) | null = null
 	let currentLocation: Location = { lat: 0, lng: 0 }
 
 	return {
@@ -63,12 +63,12 @@ function createLocationSource(): SimulatedLocationSource {
 		},
 
 		async fetchContext() {
-			return { [LocationKey]: currentLocation }
+			return [[LocationKey, currentLocation]]
 		},
 
 		simulateUpdate(location: Location) {
 			currentLocation = location
-			callback?.({ [LocationKey]: location })
+			callback?.([[LocationKey, location]])
 		},
 	}
 }
@@ -85,15 +85,15 @@ function createWeatherSource(
 		...noActions,
 
 		async fetchContext(context) {
-			const location = contextValue(context, LocationKey)
+			const location = context.get(LocationKey)
 			if (!location) return null
 
 			const weather = await fetchWeather(location)
-			return { [WeatherKey]: weather }
+			return [[WeatherKey, weather]]
 		},
 
 		async fetchItems(context) {
-			const weather = contextValue(context, WeatherKey)
+			const weather = context.get(WeatherKey)
 			if (!weather) return []
 
 			return [
@@ -123,7 +123,7 @@ function createAlertSource(): FeedSource<AlertFeedItem> {
 		},
 
 		async fetchItems(context) {
-			const weather = contextValue(context, WeatherKey)
+			const weather = context.get(WeatherKey)
 			if (!weather) return []
 
 			if (weather.condition === "storm") {
@@ -265,7 +265,7 @@ describe("FeedEngine", () => {
 				...noActions,
 				async fetchContext() {
 					order.push("location")
-					return { [LocationKey]: { lat: 51.5, lng: -0.1 } }
+					return [[LocationKey, { lat: 51.5, lng: -0.1 }]]
 				},
 			}
 
@@ -275,9 +275,9 @@ describe("FeedEngine", () => {
 				...noActions,
 				async fetchContext(ctx) {
 					order.push("weather")
-					const loc = contextValue(ctx, LocationKey)
+					const loc = ctx.get(LocationKey)
 					expect(loc).toBeDefined()
-					return { [WeatherKey]: { temperature: 20, condition: "sunny" } }
+					return [[WeatherKey, { temperature: 20, condition: "sunny" }]]
 				},
 			}
 
@@ -298,11 +298,11 @@ describe("FeedEngine", () => {
 
 			const { context } = await engine.refresh()
 
-			expect(contextValue(context, LocationKey)).toEqual({
+			expect(context.get(LocationKey)).toEqual({
 				lat: 51.5,
 				lng: -0.1,
 			})
-			expect(contextValue(context, WeatherKey)).toEqual({
+			expect(context.get(WeatherKey)).toEqual({
 				temperature: 20,
 				condition: "sunny",
 			})
@@ -361,7 +361,7 @@ describe("FeedEngine", () => {
 
 			const { context, items } = await engine.refresh()
 
-			expect(contextValue(context, WeatherKey)).toBeUndefined()
+			expect(context.get(WeatherKey)).toBeUndefined()
 			expect(items).toHaveLength(0)
 		})
 
@@ -459,7 +459,7 @@ describe("FeedEngine", () => {
 			await engine.refresh()
 
 			const context = engine.currentContext()
-			expect(contextValue(context, LocationKey)).toEqual({
+			expect(context.get(LocationKey)).toEqual({
 				lat: 51.5,
 				lng: -0.1,
 			})
@@ -734,7 +734,7 @@ describe("FeedEngine", () => {
 		})
 
 		test("reactive item update refreshes cache", async () => {
-			let itemUpdateCallback: (() => void) | null = null
+			let itemUpdateCallback: ((items: FeedItem[]) => void) | null = null
 
 			const source: FeedSource = {
 				id: "reactive-items",
@@ -765,7 +765,7 @@ describe("FeedEngine", () => {
 			engine.start()
 
 			// Trigger item update
-			itemUpdateCallback!()
+			itemUpdateCallback!([])
 
 			// Wait for async refresh
 			await new Promise((resolve) => setTimeout(resolve, 50))
@@ -885,12 +885,12 @@ describe("FeedEngine", () => {
 				...noActions,
 				async fetchContext(ctx) {
 					fetchCount++
-					const loc = contextValue(ctx, LocationKey)
+					const loc = ctx.get(LocationKey)
 					if (!loc) return null
-					return { [WeatherKey]: { temperature: 20, condition: "sunny" } }
+					return [[WeatherKey, { temperature: 20, condition: "sunny" }]]
 				},
 				async fetchItems(ctx) {
-					const weather = contextValue(ctx, WeatherKey)
+					const weather = ctx.get(WeatherKey)
 					if (!weather) return []
 					return [
 						{

packages/aris-core/src/feed-engine.ts

@@ -1,9 +1,11 @@
 import type { ActionDefinition } from "./action"
-import type { Context } from "./context"
+import type { ContextEntry } from "./context"
 import type { FeedItem } from "./feed"
 import type { FeedPostProcessor, ItemGroup } from "./feed-post-processor"
 import type { FeedSource } from "./feed-source"
 
+import { Context } from "./context"
+
 export interface SourceError {
 	sourceId: string
 	error: Error
@@ -65,7 +67,7 @@ interface SourceGraph {
 export class FeedEngine<TItems extends FeedItem = FeedItem> {
 	private sources = new Map<string, FeedSource>()
 	private graph: SourceGraph | null = null
-	private context: Context = { time: new Date() }
+	private context: Context = new Context()
 	private subscribers = new Set<FeedSubscriber<TItems>>()
 	private cleanups: Array<() => void> = []
 	private started = false
@@ -138,14 +140,14 @@ export class FeedEngine<TItems extends FeedItem = FeedItem> {
 		const errors: SourceError[] = []
 
 		// Reset context with fresh time
-		let context: Context = { time: new Date() }
+		const context = new Context()
 
 		// Run fetchContext in topological order
 		for (const source of graph.sorted) {
 			try {
-				const update = await source.fetchContext(context)
-				if (update) {
-					context = { ...context, ...update }
+				const entries = await source.fetchContext(context)
+				if (entries) {
+					context.set(entries)
 				}
 			} catch (err) {
 				errors.push({
@@ -177,7 +179,7 @@ export class FeedEngine<TItems extends FeedItem = FeedItem> {
 			items: processedItems,
 			groupedItems,
 			errors: postProcessorErrors,
-		} = await this.applyPostProcessors(items as TItems[], errors)
+		} = await this.applyPostProcessors(items as TItems[], context, errors)
 
 		const result: FeedResult<TItems> = {
 			context,
@@ -213,8 +215,8 @@ export class FeedEngine<TItems extends FeedItem = FeedItem> {
 		for (const source of graph.sorted) {
 			if (source.onContextUpdate) {
 				const cleanup = source.onContextUpdate(
-					(update) => {
-						this.handleContextUpdate(source.id, update)
+					(entries) => {
+						this.handleContextUpdate(source.id, entries)
 					},
 					() => this.context,
 				)
@@ -294,16 +296,18 @@ export class FeedEngine<TItems extends FeedItem = FeedItem> {
 
 	private async applyPostProcessors(
 		items: TItems[],
+		context: Context,
 		errors: SourceError[],
 	): Promise<{ items: TItems[]; groupedItems: ItemGroup[]; errors: SourceError[] }> {
 		let currentItems = items
 		const allGroupedItems: ItemGroup[] = []
 		const allErrors = [...errors]
+		const boostScores = new Map<string, number>()
 
 		for (const processor of this.postProcessors) {
 			const snapshot = currentItems
 			try {
-				const enhancement = await processor(currentItems)
+				const enhancement = await processor(currentItems, context)
 
 				if (enhancement.additionalItems?.length) {
 					// Post-processors operate on FeedItem[] without knowledge of TItems.
@@ -321,6 +325,12 @@ export class FeedEngine<TItems extends FeedItem = FeedItem> {
 				if (enhancement.groupedItems?.length) {
 					allGroupedItems.push(...enhancement.groupedItems)
 				}
+
+				if (enhancement.boost) {
+					for (const [id, score] of Object.entries(enhancement.boost)) {
+						boostScores.set(id, (boostScores.get(id) ?? 0) + score)
+					}
+				}
 			} catch (err) {
 				const sourceId = processor.name || "anonymous"
 				allErrors.push({
@@ -331,6 +341,12 @@ export class FeedEngine<TItems extends FeedItem = FeedItem> {
 			}
 		}
 
+		// Apply boost reordering: positive-boost first (desc), then zero, then negative (desc).
+		// Stable sort within each tier preserves original relative order.
+		if (boostScores.size > 0) {
+			currentItems = applyBoostOrder(currentItems, boostScores)
+		}
+
 		// Remove stale item IDs from groups and drop empty groups
 		const itemIds = new Set(currentItems.map((item) => item.id))
 		const validGroups = allGroupedItems.reduce<ItemGroup[]>((acc, group) => {
@@ -351,8 +367,9 @@ export class FeedEngine<TItems extends FeedItem = FeedItem> {
 		return this.graph
 	}
 
-	private handleContextUpdate(sourceId: string, update: Partial<Context>): void {
-		this.context = { ...this.context, ...update, time: new Date() }
+	private handleContextUpdate(sourceId: string, entries: readonly ContextEntry[]): void {
+		this.context.time = new Date()
+		this.context.set(entries)
 
 		// Re-run dependents and notify
 		this.refreshDependents(sourceId)
@@ -367,9 +384,9 @@ export class FeedEngine<TItems extends FeedItem = FeedItem> {
 			const source = graph.sources.get(id)
 			if (source) {
 				try {
-					const update = await source.fetchContext(this.context)
-					if (update) {
-						this.context = { ...this.context, ...update }
+					const entries = await source.fetchContext(this.context)
+					if (entries) {
+						this.context.set(entries)
 					}
 				} catch {
 					// Errors during reactive updates are logged but don't stop propagation
@@ -399,7 +416,7 @@ export class FeedEngine<TItems extends FeedItem = FeedItem> {
 			items: processedItems,
 			groupedItems,
 			errors: postProcessorErrors,
-		} = await this.applyPostProcessors(items as TItems[], errors)
+		} = await this.applyPostProcessors(items as TItems[], this.context, errors)
 
 		const result: FeedResult<TItems> = {
 			context: this.context,
@@ -486,6 +503,47 @@ export class FeedEngine<TItems extends FeedItem = FeedItem> {
 	}
 }
 
+function clamp(value: number, min: number, max: number): number {
+	return Math.min(max, Math.max(min, value))
+}
+
+function applyBoostOrder<T extends FeedItem>(items: T[], boostScores: Map<string, number>): T[] {
+	const positive: T[] = []
+	const neutral: T[] = []
+	const negative: T[] = []
+
+	for (const item of items) {
+		const raw = boostScores.get(item.id)
+		if (raw === undefined || raw === 0) {
+			neutral.push(item)
+		} else {
+			const clamped = clamp(raw, -1, 1)
+			if (clamped > 0) {
+				positive.push(item)
+			} else if (clamped < 0) {
+				negative.push(item)
+			} else {
+				neutral.push(item)
+			}
+		}
+	}
+
+	// Sort positive descending by boost, negative descending (least negative first, most negative last)
+	positive.sort((a, b) => {
+		const aScore = clamp(boostScores.get(a.id) ?? 0, -1, 1)
+		const bScore = clamp(boostScores.get(b.id) ?? 0, -1, 1)
+		return bScore - aScore
+	})
+
+	negative.sort((a, b) => {
+		const aScore = clamp(boostScores.get(a.id) ?? 0, -1, 1)
+		const bScore = clamp(boostScores.get(b.id) ?? 0, -1, 1)
+		return bScore - aScore
+	})
+
+	return [...positive, ...neutral, ...negative]
+}
+
 function buildGraph(sources: FeedSource[]): SourceGraph {
 	const byId = new Map<string, FeedSource>()
 	for (const source of sources) {

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

@@ -1,6 +1,12 @@
 import { describe, expect, mock, test } from "bun:test"
 
-import type { ActionDefinition, FeedItem, FeedPostProcessor, FeedSource } from "./index"
+import type {
+	ActionDefinition,
+	ContextEntry,
+	FeedItem,
+	FeedPostProcessor,
+	FeedSource,
+} from "./index"
 
 import { FeedEngine } from "./feed-engine"
 import { UnknownActionError } from "./index"
@@ -209,6 +215,163 @@ describe("FeedPostProcessor", () => {
 		})
 	})
 
+	// =============================================================================
+	// BOOST
+	// =============================================================================
+
+	describe("boost", () => {
+		test("positive boost moves item before non-boosted items", async () => {
+			const engine = new FeedEngine()
+				.register(createWeatherSource([weatherItem("w1", 20), weatherItem("w2", 25)]))
+				.registerPostProcessor(async () => ({ boost: { w2: 0.8 } }))
+
+			const result = await engine.refresh()
+			expect(result.items.map((i) => i.id)).toEqual(["w2", "w1"])
+		})
+
+		test("negative boost moves item after non-boosted items", async () => {
+			const engine = new FeedEngine()
+				.register(createWeatherSource([weatherItem("w1", 20), weatherItem("w2", 25)]))
+				.registerPostProcessor(async () => ({ boost: { w1: -0.5 } }))
+
+			const result = await engine.refresh()
+			expect(result.items.map((i) => i.id)).toEqual(["w2", "w1"])
+		})
+
+		test("multiple boosted items are sorted by boost descending", async () => {
+			const engine = new FeedEngine()
+				.register(
+					createWeatherSource([
+						weatherItem("w1", 20),
+						weatherItem("w2", 25),
+						weatherItem("w3", 30),
+					]),
+				)
+				.registerPostProcessor(async () => ({
+					boost: { w3: 0.3, w1: 0.9 },
+				}))
+
+			const result = await engine.refresh()
+			// w1 (0.9) first, w3 (0.3) second, w2 (no boost) last
+			expect(result.items.map((i) => i.id)).toEqual(["w1", "w3", "w2"])
+		})
+
+		test("multiple processors accumulate boost scores", async () => {
+			const engine = new FeedEngine()
+				.register(createWeatherSource([weatherItem("w1", 20), weatherItem("w2", 25)]))
+				.registerPostProcessor(async () => ({ boost: { w1: 0.3 } }))
+				.registerPostProcessor(async () => ({ boost: { w1: 0.4 } }))
+
+			const result = await engine.refresh()
+			// w1 accumulated boost = 0.7, moves before w2
+			expect(result.items.map((i) => i.id)).toEqual(["w1", "w2"])
+		})
+
+		test("accumulated boost is clamped to [-1, 1]", async () => {
+			const engine = new FeedEngine()
+				.register(
+					createWeatherSource([
+						weatherItem("w1", 20),
+						weatherItem("w2", 25),
+						weatherItem("w3", 30),
+					]),
+				)
+				.registerPostProcessor(async () => ({ boost: { w1: 0.8, w2: 0.9 } }))
+				.registerPostProcessor(async () => ({ boost: { w1: 0.8 } }))
+
+			const result = await engine.refresh()
+			// w1 accumulated = 1.6 clamped to 1, w2 = 0.9 — w1 still first
+			expect(result.items.map((i) => i.id)).toEqual(["w1", "w2", "w3"])
+		})
+
+		test("out-of-range boost values are clamped", async () => {
+			const engine = new FeedEngine()
+				.register(createWeatherSource([weatherItem("w1", 20), weatherItem("w2", 25)]))
+				.registerPostProcessor(async () => ({ boost: { w1: 5.0 } }))
+
+			const result = await engine.refresh()
+			// Clamped to 1, still boosted to front
+			expect(result.items.map((i) => i.id)).toEqual(["w1", "w2"])
+		})
+
+		test("boosting a suppressed item is a no-op", async () => {
+			const engine = new FeedEngine()
+				.register(createWeatherSource([weatherItem("w1", 20), weatherItem("w2", 25)]))
+				.registerPostProcessor(async () => ({
+					suppress: ["w1"],
+					boost: { w1: 1.0 },
+				}))
+
+			const result = await engine.refresh()
+			expect(result.items).toHaveLength(1)
+			expect(result.items[0].id).toBe("w2")
+		})
+
+		test("boosting a nonexistent item ID is a no-op", async () => {
+			const engine = new FeedEngine()
+				.register(createWeatherSource([weatherItem("w1", 20)]))
+				.registerPostProcessor(async () => ({ boost: { nonexistent: 1.0 } }))
+
+			const result = await engine.refresh()
+			expect(result.items).toHaveLength(1)
+			expect(result.items[0].id).toBe("w1")
+		})
+
+		test("items with equal boost retain original relative order", async () => {
+			const engine = new FeedEngine()
+				.register(
+					createWeatherSource([
+						weatherItem("w1", 20),
+						weatherItem("w2", 25),
+						weatherItem("w3", 30),
+					]),
+				)
+				.registerPostProcessor(async () => ({
+					boost: { w1: 0.5, w3: 0.5 },
+				}))
+
+			const result = await engine.refresh()
+			// w1 and w3 have equal boost — original order preserved: w1 before w3
+			expect(result.items.map((i) => i.id)).toEqual(["w1", "w3", "w2"])
+		})
+
+		test("negative boosts preserve relative order among demoted items", async () => {
+			const engine = new FeedEngine()
+				.register(
+					createWeatherSource([
+						weatherItem("w1", 20),
+						weatherItem("w2", 25),
+						weatherItem("w3", 30),
+					]),
+				)
+				.registerPostProcessor(async () => ({
+					boost: { w1: -0.3, w2: -0.3 },
+				}))
+
+			const result = await engine.refresh()
+			// w3 (neutral) first, then w1 and w2 (equal negative) in original order
+			expect(result.items.map((i) => i.id)).toEqual(["w3", "w1", "w2"])
+		})
+
+		test("boost works alongside additionalItems and groupedItems", async () => {
+			const extra = calendarItem("c1", "Meeting")
+
+			const engine = new FeedEngine()
+				.register(createWeatherSource([weatherItem("w1", 20), weatherItem("w2", 25)]))
+				.registerPostProcessor(async () => ({
+					additionalItems: [extra],
+					boost: { c1: 1.0 },
+					groupedItems: [{ itemIds: ["w1", "c1"], summary: "Related" }],
+				}))
+
+			const result = await engine.refresh()
+			// c1 boosted to front
+			expect(result.items[0].id).toBe("c1")
+			expect(result.items).toHaveLength(3)
+			expect(result.groupedItems).toEqual([{ itemIds: ["w1", "c1"], summary: "Related" }])
+		})
+	})
+
 	// =============================================================================
 	// PIPELINE ORDERING
 	// =============================================================================
@@ -314,7 +477,7 @@ describe("FeedPostProcessor", () => {
 		test("post-processors run during reactive context updates", async () => {
 			let callCount = 0
 
-			let triggerUpdate: ((update: Record<string, unknown>) => void) | null = null
+			let triggerUpdate: ((entries: readonly ContextEntry[]) => void) | null = null
 
 			const source: FeedSource = {
 				id: "aris.reactive",
@@ -333,12 +496,10 @@ describe("FeedPostProcessor", () => {
 				},
 			}
 
-			const engine = new FeedEngine()
-				.register(source)
-				.registerPostProcessor(async () => {
-					callCount++
-					return {}
-				})
+			const engine = new FeedEngine().register(source).registerPostProcessor(async () => {
+				callCount++
+				return {}
+			})
 
 			engine.start()
 
@@ -347,7 +508,7 @@ describe("FeedPostProcessor", () => {
 			const countAfterStart = callCount
 
 			// Trigger a reactive context update
-			triggerUpdate!({ foo: "bar" })
+			triggerUpdate!([])
 			await new Promise((resolve) => setTimeout(resolve, 50))
 
 			expect(callCount).toBeGreaterThan(countAfterStart)
@@ -358,7 +519,7 @@ describe("FeedPostProcessor", () => {
 		test("post-processors run during reactive item updates", async () => {
 			let callCount = 0
 
-			let triggerItemsUpdate: (() => void) | null = null
+			let triggerItemsUpdate: ((items: FeedItem[]) => void) | null = null
 
 			const source: FeedSource = {
 				id: "aris.reactive",
@@ -377,12 +538,10 @@ describe("FeedPostProcessor", () => {
 				},
 			}
 
-			const engine = new FeedEngine()
-				.register(source)
-				.registerPostProcessor(async () => {
-					callCount++
-					return {}
-				})
+			const engine = new FeedEngine().register(source).registerPostProcessor(async () => {
+				callCount++
+				return {}
+			})
 
 			engine.start()
 
@@ -390,7 +549,7 @@ describe("FeedPostProcessor", () => {
 			const countAfterStart = callCount
 
 			// Trigger a reactive items update
-			triggerItemsUpdate!()
+			triggerItemsUpdate!([weatherItem("w1", 25)])
 			await new Promise((resolve) => setTimeout(resolve, 50))
 
 			expect(callCount).toBeGreaterThan(countAfterStart)

packages/aris-core/src/feed-post-processor.ts

@@ -1,3 +1,4 @@
+import type { Context } from "./context"
 import type { FeedItem } from "./feed"
 
 export interface ItemGroup {
@@ -14,10 +15,12 @@ export interface FeedEnhancement {
 	groupedItems?: ItemGroup[]
 	/** Item IDs to remove from the feed */
 	suppress?: string[]
+	/** Map of item ID to boost score (-1 to 1). Positive promotes, negative demotes. */
+	boost?: Record<string, number>
 }
 
 /**
  * A function that transforms feed items and produces enhancement directives.
  * Use named functions for meaningful error attribution.
  */
-export type FeedPostProcessor = (items: FeedItem[]) => Promise<FeedEnhancement>
+export type FeedPostProcessor = (items: FeedItem[], context: Context) => Promise<FeedEnhancement>

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

@@ -1,8 +1,8 @@
 import { describe, expect, test } from "bun:test"
 
-import type { ActionDefinition, Context, ContextKey, FeedItem, FeedSource } from "./index"
+import type { ActionDefinition, ContextEntry, ContextKey, FeedItem, FeedSource } from "./index"
 
-import { TimeRelevance, UnknownActionError, contextKey, contextValue } from "./index"
+import { Context, TimeRelevance, UnknownActionError, contextKey } from "./index"
 
 // No-op action methods for test sources
 const noActions = {
@@ -47,7 +47,7 @@ interface SimulatedLocationSource extends FeedSource {
 }
 
 function createLocationSource(): SimulatedLocationSource {
-	let callback: ((update: Partial<Context>) => void) | null = null
+	let callback: ((entries: readonly ContextEntry[]) => void) | null = null
 	let currentLocation: Location = { lat: 0, lng: 0 }
 
 	return {
@@ -62,12 +62,12 @@ function createLocationSource(): SimulatedLocationSource {
 		},
 
 		async fetchContext() {
-			return { [LocationKey]: currentLocation }
+			return [[LocationKey, currentLocation]]
 		},
 
 		simulateUpdate(location: Location) {
 			currentLocation = location
-			callback?.({ [LocationKey]: location })
+			callback?.([[LocationKey, location]])
 		},
 	}
 }
@@ -84,15 +84,15 @@ function createWeatherSource(
 		...noActions,
 
 		async fetchContext(context) {
-			const location = contextValue(context, LocationKey)
+			const location = context.get(LocationKey)
 			if (!location) return null
 
 			const weather = await fetchWeather(location)
-			return { [WeatherKey]: weather }
+			return [[WeatherKey, weather]]
 		},
 
 		async fetchItems(context) {
-			const weather = contextValue(context, WeatherKey)
+			const weather = context.get(WeatherKey)
 			if (!weather) return []
 
 			return [
@@ -122,7 +122,7 @@ function createAlertSource(): FeedSource<AlertFeedItem> {
 		},
 
 		async fetchItems(context) {
-			const weather = contextValue(context, WeatherKey)
+			const weather = context.get(WeatherKey)
 			if (!weather) return []
 
 			if (weather.condition === "storm") {
@@ -207,13 +207,13 @@ function buildGraph(sources: FeedSource[]): SourceGraph {
 }
 
 async function refreshGraph(graph: SourceGraph): Promise<{ context: Context; items: FeedItem[] }> {
-	let context: Context = { time: new Date() }
+	const context = new Context()
 
 	// Run fetchContext in topological order
 	for (const source of graph.sorted) {
-		const update = await source.fetchContext(context)
-		if (update) {
-			context = { ...context, ...update }
+		const entries = await source.fetchContext(context)
+		if (entries) {
+			context.set(entries)
 		}
 	}
 
@@ -265,7 +265,7 @@ describe("FeedSource", () => {
 
 		test("source without context returns null from fetchContext", async () => {
 			const source = createAlertSource()
-			const result = await source.fetchContext({ time: new Date() })
+			const result = await source.fetchContext(new Context())
 			expect(result).toBeNull()
 		})
 	})
@@ -369,7 +369,7 @@ describe("FeedSource", () => {
 				...noActions,
 				async fetchContext() {
 					order.push("location")
-					return { [LocationKey]: { lat: 51.5, lng: -0.1 } }
+					return [[LocationKey, { lat: 51.5, lng: -0.1 }]]
 				},
 			}
 
@@ -379,9 +379,9 @@ describe("FeedSource", () => {
 				...noActions,
 				async fetchContext(ctx) {
 					order.push("weather")
-					const loc = contextValue(ctx, LocationKey)
+					const loc = ctx.get(LocationKey)
 					expect(loc).toBeDefined()
-					return { [WeatherKey]: { temperature: 20, condition: "sunny" } }
+					return [[WeatherKey, { temperature: 20, condition: "sunny" }]]
 				},
 			}
 
@@ -400,11 +400,11 @@ describe("FeedSource", () => {
 			const graph = buildGraph([location, weather])
 			const { context } = await refreshGraph(graph)
 
-			expect(contextValue(context, LocationKey)).toEqual({
+			expect(context.get(LocationKey)).toEqual({
 				lat: 51.5,
 				lng: -0.1,
 			})
-			expect(contextValue(context, WeatherKey)).toEqual({
+			expect(context.get(WeatherKey)).toEqual({
 				temperature: 20,
 				condition: "sunny",
 			})
@@ -447,12 +447,10 @@ describe("FeedSource", () => {
 		})
 
 		test("source without location context returns empty items", async () => {
-			// Location source exists but hasn't been updated
 			const location: FeedSource = {
 				id: "location",
 				...noActions,
 				async fetchContext() {
-					// Simulate no location available
 					return null
 				},
 			}
@@ -462,7 +460,7 @@ describe("FeedSource", () => {
 			const graph = buildGraph([location, weather])
 			const { context, items } = await refreshGraph(graph)
 
-			expect(contextValue(context, WeatherKey)).toBeUndefined()
+			expect(context.get(WeatherKey)).toBeUndefined()
 			expect(items).toHaveLength(0)
 		})
 	})
@@ -476,7 +474,7 @@ describe("FeedSource", () => {
 				() => {
 					updateCount++
 				},
-				() => ({ time: new Date() }),
+				() => new Context(),
 			)
 
 			location.simulateUpdate({ lat: 1, lng: 1 })

packages/aris-core/src/feed-source.ts

@@ -1,5 +1,5 @@
 import type { ActionDefinition } from "./action"
-import type { Context } from "./context"
+import type { Context, ContextEntry } from "./context"
 import type { FeedItem } from "./feed"
 
 /**
@@ -57,7 +57,7 @@ export interface FeedSource<TItem extends FeedItem = FeedItem> {
 	 * Maps to: source/contextUpdated (notification, source → host)
 	 */
 	onContextUpdate?(
-		callback: (update: Partial<Context>) => void,
+		callback: (entries: readonly ContextEntry[]) => void,
 		getContext: () => Context,
 	): () => void
 
@@ -67,7 +67,7 @@ export interface FeedSource<TItem extends FeedItem = FeedItem> {
 	 * Return null if this source cannot provide context.
 	 * Maps to: source/fetchContext
 	 */
-	fetchContext(context: Context): Promise<Partial<Context> | null>
+	fetchContext(context: Context): Promise<readonly ContextEntry[] | null>
 
 	/**
 	 * Subscribe to reactive feed item updates.

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

@@ -0,0 +1,87 @@
+import { describe, expect, test } from "bun:test"
+
+import type { FeedItem, Slot } from "./feed"
+
+describe("FeedItem slots", () => {
+	test("FeedItem without slots is valid", () => {
+		const item: FeedItem<"test", { value: number }> = {
+			id: "test-1",
+			type: "test",
+			timestamp: new Date(),
+			data: { value: 42 },
+		}
+
+		expect(item.slots).toBeUndefined()
+	})
+
+	test("FeedItem with unfilled slots", () => {
+		const item: FeedItem<"weather", { temp: number }> = {
+			id: "weather-1",
+			type: "weather",
+			timestamp: new Date(),
+			data: { temp: 18 },
+			slots: {
+				insight: {
+					description: "A short contextual insight about the current weather",
+					content: null,
+				},
+				"cross-source": {
+					description: "Connection between weather and calendar events",
+					content: null,
+				},
+			},
+		}
+
+		expect(item.slots).toBeDefined()
+		expect(Object.keys(item.slots!)).toEqual(["insight", "cross-source"])
+		expect(item.slots!.insight!.content).toBeNull()
+		expect(item.slots!["cross-source"]!.content).toBeNull()
+	})
+
+	test("FeedItem with filled slots", () => {
+		const item: FeedItem<"weather", { temp: number }> = {
+			id: "weather-1",
+			type: "weather",
+			timestamp: new Date(),
+			data: { temp: 18 },
+			slots: {
+				insight: {
+					description: "A short contextual insight about the current weather",
+					content: "Rain after 3pm — grab a jacket before your walk",
+				},
+			},
+		}
+
+		expect(item.slots!.insight!.content).toBe("Rain after 3pm — grab a jacket before your walk")
+	})
+
+	test("Slot interface enforces required fields", () => {
+		const slot: Slot = {
+			description: "Test slot description",
+			content: null,
+		}
+
+		expect(slot.description).toBe("Test slot description")
+		expect(slot.content).toBeNull()
+
+		const filledSlot: Slot = {
+			description: "Test slot description",
+			content: "Filled content",
+		}
+
+		expect(filledSlot.content).toBe("Filled content")
+	})
+
+	test("FeedItem with empty slots record", () => {
+		const item: FeedItem<"test", { value: number }> = {
+			id: "test-1",
+			type: "test",
+			timestamp: new Date(),
+			data: { value: 1 },
+			slots: {},
+		}
+
+		expect(item.slots).toEqual({})
+		expect(Object.keys(item.slots!)).toHaveLength(0)
+	})
+})

packages/aris-core/src/feed.ts

@@ -23,6 +23,20 @@ export interface FeedItemSignals {
 	timeRelevance?: TimeRelevance
 }
 
+/**
+ * A named slot for LLM-fillable content on a feed item.
+ *
+ * Sources declare slots with a description that tells the LLM what content
+ * to generate. The enhancement harness fills `content` asynchronously;
+ * until then it remains `null`.
+ */
+export interface Slot {
+	/** Tells the LLM what this slot wants — written by the source */
+	description: string
+	/** LLM-filled text content, null until enhanced */
+	content: string | null
+}
+
 /**
  * A single item in the feed.
  *
@@ -36,6 +50,12 @@ export interface FeedItemSignals {
  *   timestamp: new Date(),
  *   data: { temp: 18, condition: "cloudy" },
  *   signals: { urgency: 0.5, timeRelevance: "ambient" },
+ *   slots: {
+ *     insight: {
+ *       description: "A short contextual insight about the current weather",
+ *       content: null,
+ *     },
+ *   },
  * }
  * ```
  */
@@ -53,4 +73,6 @@ export interface FeedItem<
 	data: TData
 	/** Source-provided hints for post-processors. Optional — omit if no signals apply. */
 	signals?: FeedItemSignals
+	/** Named slots for LLM-fillable content. Keys are slot names. */
+	slots?: Record<string, Slot>
 }

packages/aris-core/src/index.ts

@@ -1,13 +1,13 @@
 // Context
-export type { Context, ContextKey } from "./context"
-export { contextKey, contextValue } from "./context"
+export type { ContextEntry, ContextKey, ContextKeyPart } from "./context"
+export { Context, contextKey, serializeKey } from "./context"
 
 // Actions
 export type { ActionDefinition } from "./action"
 export { UnknownActionError } from "./action"
 
 // Feed
-export type { FeedItem, FeedItemSignals } from "./feed"
+export type { FeedItem, FeedItemSignals, Slot } from "./feed"
 export { TimeRelevance } from "./feed"
 
 // Feed Source

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

@@ -1,5 +1,6 @@
-import type { Context } from "@aris/core"
+import type { ContextKey } from "@aris/core"
 
+import { Context, contextKey } from "@aris/core"
 import { describe, expect, test } from "bun:test"
 
 import type { WeatherKitClient, WeatherKitResponse } from "./weatherkit"
@@ -15,14 +16,25 @@ const mockCredentials = {
 	serviceId: "mock",
 }
 
+interface LocationData {
+	lat: number
+	lng: number
+	accuracy: number
+}
+
+const LocationKey: ContextKey<LocationData> = contextKey("aris.location", "location")
+
 const createMockClient = (response: WeatherKitResponse): WeatherKitClient => ({
 	fetch: async () => response,
 })
 
-const createMockContext = (location?: { lat: number; lng: number }): Context => ({
-	time: new Date("2026-01-17T00:00:00Z"),
-	location: location ? { ...location, accuracy: 10 } : undefined,
-})
+function createMockContext(location?: { lat: number; lng: number }): Context {
+	const ctx = new Context(new Date("2026-01-17T00:00:00Z"))
+	if (location) {
+		ctx.set([[LocationKey, { ...location, accuracy: 10 }]])
+	}
+	return ctx
+}
 
 describe("WeatherKitDataSource", () => {
 	test("returns empty array when location is missing", async () => {
@@ -39,7 +51,7 @@ describe("WeatherKitDataSource", () => {
 			credentials: mockCredentials,
 		})
 
-		expect(dataSource.type).toBe(WeatherFeedItemType.current)
+		expect(dataSource.type).toBe(WeatherFeedItemType.Current)
 	})
 
 	test("throws error if neither client nor credentials provided", () => {
@@ -130,9 +142,9 @@ describe("query() with mocked client", () => {
 		const items = await dataSource.query(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)
+		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 () => {
@@ -145,8 +157,8 @@ describe("query() with mocked client", () => {
 
 		const items = await dataSource.query(context)
 
-		const hourlyItems = items.filter((i) => i.type === WeatherFeedItemType.hourly)
-		const dailyItems = items.filter((i) => i.type === WeatherFeedItemType.daily)
+		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)
@@ -176,8 +188,8 @@ describe("query() with mocked client", () => {
 			units: Units.imperial,
 		})
 
-		const metricCurrent = metricItems.find((i) => i.type === WeatherFeedItemType.current)
-		const imperialCurrent = imperialItems.find((i) => i.type === WeatherFeedItemType.current)
+		const metricCurrent = metricItems.find((i) => i.type === WeatherFeedItemType.Current)
+		const imperialCurrent = imperialItems.find((i) => i.type === WeatherFeedItemType.Current)
 
 		expect(metricCurrent).toBeDefined()
 		expect(imperialCurrent).toBeDefined()
@@ -203,7 +215,7 @@ describe("query() with mocked client", () => {
 			expect(item.signals!.timeRelevance).toBeDefined()
 		}
 
-		const currentItem = items.find((i) => i.type === WeatherFeedItemType.current)
+		const currentItem = items.find((i) => i.type === WeatherFeedItemType.Current)
 		expect(currentItem).toBeDefined()
 		expect(currentItem!.signals!.urgency).toBeGreaterThanOrEqual(0.5)
 	})

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

@@ -1,6 +1,6 @@
-import type { Context, DataSource, FeedItemSignals } from "@aris/core"
+import type { Context, ContextKey, DataSource, FeedItemSignals } from "@aris/core"
 
-import { TimeRelevance } from "@aris/core"
+import { TimeRelevance, contextKey } from "@aris/core"
 
 import {
 	WeatherFeedItemType,
@@ -40,11 +40,18 @@ export interface WeatherKitQueryConfig {
 	units?: Units
 }
 
+interface LocationData {
+	lat: number
+	lng: number
+}
+
+const LocationKey: ContextKey<LocationData> = contextKey("aris.location", "location")
+
 export class WeatherKitDataSource implements DataSource<WeatherFeedItem, WeatherKitQueryConfig> {
 	private readonly DEFAULT_HOURLY_LIMIT = 12
 	private readonly DEFAULT_DAILY_LIMIT = 7
 
-	readonly type = WeatherFeedItemType.current
+	readonly type = WeatherFeedItemType.Current
 	private readonly client: WeatherKitClient
 	private readonly hourlyLimit: number
 	private readonly dailyLimit: number
@@ -59,7 +66,8 @@ export class WeatherKitDataSource implements DataSource<WeatherFeedItem, Weather
 	}
 
 	async query(context: Context, config: WeatherKitQueryConfig = {}): Promise<WeatherFeedItem[]> {
-		if (!context.location) {
+		const location = context.get(LocationKey)
+		if (!location) {
 			return []
 		}
 
@@ -67,8 +75,8 @@ export class WeatherKitDataSource implements DataSource<WeatherFeedItem, Weather
 		const timestamp = context.time
 
 		const response = await this.client.fetch({
-			lat: context.location.lat,
-			lng: context.location.lng,
+			lat: location.lat,
+			lng: location.lng,
 		})
 
 		const items: WeatherFeedItem[] = []
@@ -228,7 +236,7 @@ function createCurrentWeatherFeedItem(
 
 	return {
 		id: `weather-current-${timestamp.getTime()}`,
-		type: WeatherFeedItemType.current,
+		type: WeatherFeedItemType.Current,
 		timestamp,
 		data: {
 			conditionCode: current.conditionCode,
@@ -262,7 +270,7 @@ function createHourlyWeatherFeedItem(
 
 	return {
 		id: `weather-hourly-${timestamp.getTime()}-${index}`,
-		type: WeatherFeedItemType.hourly,
+		type: WeatherFeedItemType.Hourly,
 		timestamp,
 		data: {
 			forecastTime: new Date(hourly.forecastStart),
@@ -296,7 +304,7 @@ function createDailyWeatherFeedItem(
 
 	return {
 		id: `weather-daily-${timestamp.getTime()}-${index}`,
-		type: WeatherFeedItemType.daily,
+		type: WeatherFeedItemType.Daily,
 		timestamp,
 		data: {
 			forecastDate: new Date(daily.forecastStart),
@@ -323,7 +331,7 @@ function createWeatherAlertFeedItem(alert: WeatherAlert, timestamp: Date): Weath
 
 	return {
 		id: `weather-alert-${alert.id}`,
-		type: WeatherFeedItemType.alert,
+		type: WeatherFeedItemType.Alert,
 		timestamp,
 		data: {
 			alertId: alert.id,

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

@@ -3,10 +3,10 @@ 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",
+	Current: "weather-current",
+	Hourly: "weather-hourly",
+	Daily: "weather-daily",
+	Alert: "weather-alert",
 } as const
 
 export type WeatherFeedItemType = (typeof WeatherFeedItemType)[keyof typeof WeatherFeedItemType]
@@ -28,7 +28,7 @@ export type CurrentWeatherData = {
 }
 
 export interface CurrentWeatherFeedItem extends FeedItem<
-	typeof WeatherFeedItemType.current,
+	typeof WeatherFeedItemType.Current,
 	CurrentWeatherData
 > {}
 
@@ -49,7 +49,7 @@ export type HourlyWeatherData = {
 }
 
 export interface HourlyWeatherFeedItem extends FeedItem<
-	typeof WeatherFeedItemType.hourly,
+	typeof WeatherFeedItemType.Hourly,
 	HourlyWeatherData
 > {}
 
@@ -68,7 +68,7 @@ export type DailyWeatherData = {
 }
 
 export interface DailyWeatherFeedItem extends FeedItem<
-	typeof WeatherFeedItemType.daily,
+	typeof WeatherFeedItemType.Daily,
 	DailyWeatherData
 > {}
 
@@ -86,7 +86,7 @@ export type WeatherAlertData = {
 }
 
 export interface WeatherAlertFeedItem extends FeedItem<
-	typeof WeatherFeedItemType.alert,
+	typeof WeatherFeedItemType.Alert,
 	WeatherAlertData
 > {}
 

packages/aris-feed-enhancers/package.json

@@ -0,0 +1,17 @@
+{
+	"name": "@aris/feed-enhancers",
+	"version": "0.0.0",
+	"type": "module",
+	"main": "src/index.ts",
+	"types": "src/index.ts",
+	"scripts": {
+		"test": "bun test src/"
+	},
+	"dependencies": {
+		"@aris/core": "workspace:*",
+		"@aris/source-caldav": "workspace:*",
+		"@aris/source-google-calendar": "workspace:*",
+		"@aris/source-tfl": "workspace:*",
+		"@aris/source-weatherkit": "workspace:*"
+	}
+}

packages/aris-feed-enhancers/src/index.ts

@@ -0,0 +1 @@
+export { createTimeOfDayEnhancer, type TimeOfDayEnhancerOptions } from "./time-of-day-enhancer.ts"

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

@@ -0,0 +1,704 @@
+import type { FeedItem, FeedItemSignals } from "@aris/core"
+
+import { Context, TimeRelevance } from "@aris/core"
+import { CalDavFeedItemType } from "@aris/source-caldav"
+import { CalendarFeedItemType } from "@aris/source-google-calendar"
+import { TflFeedItemType } from "@aris/source-tfl"
+import { WeatherFeedItemType } from "@aris/source-weatherkit"
+import { describe, expect, test } from "bun:test"
+
+import {
+	createTimeOfDayEnhancer,
+	getTimePeriod,
+	getDayType,
+	TimePeriod,
+	DayType,
+} from "./time-of-day-enhancer"
+
+// =============================================================================
+// Helpers
+// =============================================================================
+
+function makeContext(date: Date): Context {
+	return new Context(date)
+}
+
+function makeDate(year: number, month: number, day: number, hour: number, minute = 0): Date {
+	return new Date(year, month - 1, day, hour, minute, 0, 0)
+}
+
+/** Tuesday 2025-07-08 at given hour:minute */
+function tuesday(hour: number, minute = 0): Date {
+	return makeDate(2025, 7, 8, hour, minute)
+}
+
+/** Saturday 2025-07-12 at given hour:minute */
+function saturday(hour: number, minute = 0): Date {
+	return makeDate(2025, 7, 12, hour, minute)
+}
+
+function weatherCurrent(id = "w-current"): FeedItem {
+	return {
+		id,
+		type: WeatherFeedItemType.Current,
+		timestamp: new Date(),
+		data: { temperature: 18, precipitationIntensity: 0 },
+	}
+}
+
+function weatherCurrentRainy(id = "w-current-rain"): FeedItem {
+	return {
+		id,
+		type: WeatherFeedItemType.Current,
+		timestamp: new Date(),
+		data: { temperature: 12, precipitationIntensity: 2.5 },
+	}
+}
+
+function weatherCurrentExtreme(id = "w-current-extreme"): FeedItem {
+	return {
+		id,
+		type: WeatherFeedItemType.Current,
+		timestamp: new Date(),
+		data: { temperature: -5, precipitationIntensity: 0 },
+	}
+}
+
+function weatherHourly(id = "w-hourly"): FeedItem {
+	return {
+		id,
+		type: WeatherFeedItemType.Hourly,
+		timestamp: new Date(),
+		data: { forecastTime: new Date(), temperature: 20 },
+	}
+}
+
+function weatherDaily(id = "w-daily"): FeedItem {
+	return {
+		id,
+		type: WeatherFeedItemType.Daily,
+		timestamp: new Date(),
+		data: { forecastDate: new Date() },
+	}
+}
+
+function weatherAlert(id = "w-alert", urgency = 0.9): FeedItem {
+	return {
+		id,
+		type: WeatherFeedItemType.Alert,
+		timestamp: new Date(),
+		data: { severity: "extreme" },
+		signals: { urgency, timeRelevance: TimeRelevance.Imminent },
+	}
+}
+
+function calendarEvent(
+	id: string,
+	startTime: Date,
+	options: { location?: string; signals?: FeedItemSignals } = {},
+): FeedItem {
+	return {
+		id,
+		type: CalendarFeedItemType.Event,
+		timestamp: new Date(),
+		data: {
+			eventId: id,
+			calendarId: "primary",
+			title: `Event ${id}`,
+			description: null,
+			location: options.location ?? null,
+			startTime,
+			endTime: new Date(startTime.getTime() + 3_600_000),
+			isAllDay: false,
+			status: "confirmed",
+			htmlLink: "",
+		},
+		signals: options.signals,
+	}
+}
+
+function calendarAllDay(id: string): FeedItem {
+	return {
+		id,
+		type: CalendarFeedItemType.AllDay,
+		timestamp: new Date(),
+		data: {
+			eventId: id,
+			calendarId: "primary",
+			title: `All Day ${id}`,
+			description: null,
+			location: null,
+			startTime: new Date(),
+			endTime: new Date(),
+			isAllDay: true,
+			status: "confirmed",
+			htmlLink: "",
+		},
+		signals: { timeRelevance: TimeRelevance.Ambient },
+	}
+}
+
+function caldavEvent(
+	id: string,
+	startDate: Date,
+	options: { location?: string; signals?: FeedItemSignals } = {},
+): FeedItem {
+	return {
+		id,
+		type: CalDavFeedItemType.Event,
+		timestamp: new Date(),
+		data: {
+			uid: id,
+			title: `CalDAV ${id}`,
+			startDate,
+			endDate: new Date(startDate.getTime() + 3_600_000),
+			isAllDay: false,
+			location: options.location ?? null,
+			description: null,
+			calendarName: null,
+			status: "confirmed",
+			url: null,
+			organizer: null,
+			attendees: [],
+			alarms: [],
+			recurrenceId: null,
+		},
+		signals: options.signals,
+	}
+}
+
+function tflAlert(id = "tfl-1", urgency = 0.8): FeedItem {
+	return {
+		id,
+		type: TflFeedItemType.Alert,
+		timestamp: new Date(),
+		data: {
+			line: "northern",
+			lineName: "Northern",
+			severity: "major-delays",
+			description: "Delays",
+		},
+		signals: { urgency, timeRelevance: TimeRelevance.Imminent },
+	}
+}
+
+function unknownItem(id = "unknown-1"): FeedItem {
+	return {
+		id,
+		type: "some-future-type",
+		timestamp: new Date(),
+		data: { foo: "bar" },
+	}
+}
+
+// =============================================================================
+// Period detection
+// =============================================================================
+
+describe("getTimePeriod", () => {
+	test("morning: 06:00–11:59", () => {
+		expect(getTimePeriod(tuesday(6))).toBe(TimePeriod.Morning)
+		expect(getTimePeriod(tuesday(8))).toBe(TimePeriod.Morning)
+		expect(getTimePeriod(tuesday(11, 59))).toBe(TimePeriod.Morning)
+	})
+
+	test("afternoon: 12:00–16:59", () => {
+		expect(getTimePeriod(tuesday(12))).toBe(TimePeriod.Afternoon)
+		expect(getTimePeriod(tuesday(14))).toBe(TimePeriod.Afternoon)
+		expect(getTimePeriod(tuesday(16, 59))).toBe(TimePeriod.Afternoon)
+	})
+
+	test("evening: 17:00–21:59", () => {
+		expect(getTimePeriod(tuesday(17))).toBe(TimePeriod.Evening)
+		expect(getTimePeriod(tuesday(19))).toBe(TimePeriod.Evening)
+		expect(getTimePeriod(tuesday(21, 59))).toBe(TimePeriod.Evening)
+	})
+
+	test("night: 22:00–05:59", () => {
+		expect(getTimePeriod(tuesday(22))).toBe(TimePeriod.Night)
+		expect(getTimePeriod(tuesday(0))).toBe(TimePeriod.Night)
+		expect(getTimePeriod(tuesday(3))).toBe(TimePeriod.Night)
+		expect(getTimePeriod(tuesday(5, 59))).toBe(TimePeriod.Night)
+	})
+})
+
+describe("getDayType", () => {
+	test("weekday: Monday–Friday", () => {
+		// 2025-07-07 is Monday, 2025-07-08 is Tuesday, 2025-07-11 is Friday
+		expect(getDayType(makeDate(2025, 7, 7, 10))).toBe(DayType.Weekday)
+		expect(getDayType(tuesday(10))).toBe(DayType.Weekday)
+		expect(getDayType(makeDate(2025, 7, 11, 10))).toBe(DayType.Weekday)
+	})
+
+	test("weekend: Saturday–Sunday", () => {
+		expect(getDayType(saturday(10))).toBe(DayType.Weekend)
+		expect(getDayType(makeDate(2025, 7, 13, 10))).toBe(DayType.Weekend) // Sunday
+	})
+})
+
+// =============================================================================
+// Morning
+// =============================================================================
+
+describe("morning weekday", () => {
+	const now = tuesday(8)
+	const ctx = makeContext(now)
+
+	test("boosts weather-current and weather-alert, demotes weather-hourly", async () => {
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const items = [weatherCurrent(), weatherHourly(), weatherAlert()]
+		const result = await enhancer(items, ctx)
+
+		expect(result.boost!["w-current"]).toBeGreaterThan(0)
+		expect(result.boost!["w-alert"]).toBeGreaterThan(0)
+		expect(result.boost!["w-hourly"]).toBeLessThan(0)
+	})
+
+	test("boosts first calendar event of the day", async () => {
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const event1 = calendarEvent("c1", tuesday(9))
+		const event2 = calendarEvent("c2", tuesday(14))
+		const result = await enhancer([event1, event2], ctx)
+
+		expect(result.boost!["c1"]).toBeGreaterThan(0)
+		// Second event should not get the first-event boost
+		expect(result.boost?.["c2"] ?? 0).toBeLessThanOrEqual(0)
+	})
+
+	test("boosts TfL alerts", async () => {
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const result = await enhancer([tflAlert()], ctx)
+
+		expect(result.boost!["tfl-1"]).toBeGreaterThan(0)
+	})
+})
+
+describe("morning weekend", () => {
+	const now = saturday(9)
+	const ctx = makeContext(now)
+
+	test("boosts weather-current and weather-daily", async () => {
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const items = [weatherCurrent(), weatherDaily()]
+		const result = await enhancer(items, ctx)
+
+		expect(result.boost!["w-current"]).toBeGreaterThan(0)
+		expect(result.boost!["w-daily"]).toBeGreaterThan(0)
+	})
+
+	test("demotes calendar events and TfL alerts", async () => {
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const event = calendarEvent("c1", saturday(10))
+		const items = [event, tflAlert()]
+		const result = await enhancer(items, ctx)
+
+		expect(result.boost!["c1"]).toBeLessThan(0)
+		expect(result.boost!["tfl-1"]).toBeLessThan(0)
+	})
+})
+
+// =============================================================================
+// Afternoon
+// =============================================================================
+
+describe("afternoon weekday", () => {
+	const now = tuesday(14)
+	const ctx = makeContext(now)
+
+	test("boosts imminent calendar events", async () => {
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const event = calendarEvent("c1", tuesday(14, 10), {
+			signals: { timeRelevance: TimeRelevance.Imminent },
+		})
+		const result = await enhancer([event], ctx)
+
+		expect(result.boost!["c1"]).toBeGreaterThan(0)
+	})
+
+	test("demotes weather-current and weather-hourly", async () => {
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const items = [weatherCurrent(), weatherHourly()]
+		const result = await enhancer(items, ctx)
+
+		expect(result.boost!["w-current"]).toBeLessThan(0)
+		expect(result.boost!["w-hourly"]).toBeLessThan(0)
+	})
+})
+
+describe("afternoon weekend", () => {
+	const now = saturday(14)
+	const ctx = makeContext(now)
+
+	test("boosts weather-current, demotes calendar events", async () => {
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const event = calendarEvent("c1", saturday(15))
+		const items = [weatherCurrent(), event]
+		const result = await enhancer(items, ctx)
+
+		expect(result.boost!["w-current"]).toBeGreaterThan(0)
+		expect(result.boost!["c1"]).toBeLessThan(0)
+	})
+})
+
+// =============================================================================
+// Evening
+// =============================================================================
+
+describe("evening weekday", () => {
+	const now = tuesday(19)
+	const ctx = makeContext(now)
+
+	test("suppresses ambient work calendar events", async () => {
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const event = calendarEvent("c1", tuesday(9), {
+			signals: { timeRelevance: TimeRelevance.Ambient },
+		})
+		const result = await enhancer([event], ctx)
+
+		expect(result.suppress).toContain("c1")
+	})
+
+	test("demotes TfL alerts", async () => {
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const result = await enhancer([tflAlert()], ctx)
+
+		expect(result.boost!["tfl-1"]).toBeLessThan(0)
+	})
+
+	test("boosts weather-daily and all-day calendar events", async () => {
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const items = [weatherDaily(), calendarAllDay("ad1")]
+		const result = await enhancer(items, ctx)
+
+		expect(result.boost!["w-daily"]).toBeGreaterThan(0)
+		expect(result.boost!["ad1"]).toBeGreaterThan(0)
+	})
+})
+
+describe("evening weekend", () => {
+	const now = saturday(19)
+	const ctx = makeContext(now)
+
+	test("boosts weather-current, suppresses ambient calendar events", async () => {
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const event = calendarEvent("c1", saturday(9), {
+			signals: { timeRelevance: TimeRelevance.Ambient },
+		})
+		const items = [weatherCurrent(), event]
+		const result = await enhancer(items, ctx)
+
+		expect(result.boost!["w-current"]).toBeGreaterThan(0)
+		expect(result.suppress).toContain("c1")
+	})
+
+	test("demotes TfL alerts more aggressively", async () => {
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const result = await enhancer([tflAlert()], ctx)
+
+		expect(result.boost!["tfl-1"]).toBeLessThan(-0.3)
+	})
+})
+
+// =============================================================================
+// Night
+// =============================================================================
+
+describe("night", () => {
+	const now = tuesday(23)
+	const ctx = makeContext(now)
+
+	test("suppresses ambient items", async () => {
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const event = calendarEvent("c1", tuesday(9), {
+			signals: { timeRelevance: TimeRelevance.Ambient },
+		})
+		const result = await enhancer([event], ctx)
+
+		expect(result.suppress).toContain("c1")
+	})
+
+	test("demotes calendar events and weather-current", async () => {
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const event = calendarEvent("c1", makeDate(2025, 7, 9, 9)) // tomorrow
+		const items = [event, weatherCurrent()]
+		const result = await enhancer(items, ctx)
+
+		expect(result.boost!["c1"]).toBeLessThan(0)
+		expect(result.boost!["w-current"]).toBeLessThan(0)
+	})
+
+	test("high-urgency alerts survive unboosted", async () => {
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const alert = weatherAlert("w-alert", 0.9)
+		const result = await enhancer([alert], ctx)
+
+		// Should not be demoted — either no boost entry or >= 0
+		const alertBoost = result.boost?.["w-alert"] ?? 0
+		expect(alertBoost).toBeGreaterThanOrEqual(0)
+	})
+})
+
+// =============================================================================
+// Pre-meeting window
+// =============================================================================
+
+describe("pre-meeting window", () => {
+	test("boosts upcoming meeting to +0.9", async () => {
+		const now = tuesday(9, 45)
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const meeting = calendarEvent("c1", tuesday(10))
+		const result = await enhancer([meeting], makeContext(now))
+
+		expect(result.boost!["c1"]).toBe(0.9)
+	})
+
+	test("suppresses low-urgency items during pre-meeting", async () => {
+		const now = tuesday(9, 45)
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const meeting = calendarEvent("c1", tuesday(10))
+		const lowPriority = weatherHourly()
+		lowPriority.signals = { urgency: 0.1 }
+		const result = await enhancer([meeting, lowPriority], makeContext(now))
+
+		expect(result.suppress).toContain("w-hourly")
+	})
+
+	test("does not suppress items without signals during pre-meeting", async () => {
+		const now = tuesday(9, 45)
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const meeting = calendarEvent("c1", tuesday(10))
+		const noSignals = weatherDaily()
+		const result = await enhancer([meeting, noSignals], makeContext(now))
+
+		expect(result.suppress ?? []).not.toContain("w-daily")
+	})
+
+	test("boosts TfL alerts during pre-meeting", async () => {
+		const now = tuesday(9, 45)
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const meeting = calendarEvent("c1", tuesday(10))
+		const result = await enhancer([meeting, tflAlert()], makeContext(now))
+
+		expect(result.boost!["tfl-1"]).toBeGreaterThan(0)
+	})
+
+	test("boosts weather-current if meeting has a location", async () => {
+		const now = tuesday(9, 45)
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const meeting = calendarEvent("c1", tuesday(10), { location: "Office, London" })
+		const result = await enhancer([meeting, weatherCurrent()], makeContext(now))
+
+		expect(result.boost!["w-current"]).toBeGreaterThan(0)
+	})
+
+	test("works with CalDAV events", async () => {
+		const now = tuesday(9, 45)
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const meeting = caldavEvent("cd1", tuesday(10))
+		const result = await enhancer([meeting], makeContext(now))
+
+		expect(result.boost!["cd1"]).toBe(0.9)
+	})
+
+	test("does not trigger for events more than 30 minutes away", async () => {
+		const now = tuesday(9)
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const meeting = calendarEvent("c1", tuesday(10))
+		const result = await enhancer([meeting], makeContext(now))
+
+		// Should not get the +0.9 pre-meeting boost
+		expect(result.boost?.["c1"] ?? 0).not.toBe(0.9)
+	})
+})
+
+// =============================================================================
+// Wind-down gradient
+// =============================================================================
+
+describe("wind-down gradient", () => {
+	test("20:00 weekday: additional -0.1 on work items", async () => {
+		const now = tuesday(20)
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		// Non-ambient calendar event — evening rules don't boost or suppress it,
+		// so the only demotion comes from wind-down at 20:00 (-0.1).
+		const event = calendarEvent("c1", makeDate(2025, 7, 9, 9))
+		const result = await enhancer([event], makeContext(now))
+
+		expect(result.boost!["c1"]).toBe(-0.1)
+	})
+
+	test("21:00 weekday: additional -0.2 on work items", async () => {
+		const now = tuesday(21)
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const alert = tflAlert("tfl-1", 0.5)
+		const result = await enhancer([alert], makeContext(now))
+
+		// Evening demotes TfL by -0.4, wind-down adds -0.2 = -0.6
+		expect(result.boost!["tfl-1"]).toBeLessThanOrEqual(-0.6)
+	})
+
+	test("21:30 weekday: additional -0.3 on work items", async () => {
+		const now = tuesday(21, 30)
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const alert = tflAlert("tfl-1", 0.5)
+		const result = await enhancer([alert], makeContext(now))
+
+		// Evening demotes TfL by -0.4, wind-down adds -0.3 = -0.7
+		expect(result.boost!["tfl-1"]).toBeLessThanOrEqual(-0.7)
+	})
+
+	test("does not apply on weekends", async () => {
+		const now = saturday(21)
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const alert = tflAlert("tfl-1", 0.5)
+		const result = await enhancer([alert], makeContext(now))
+
+		// Weekend evening demotes TfL by -0.5, but no wind-down
+		expect(result.boost!["tfl-1"]).toBe(-0.5)
+	})
+})
+
+// =============================================================================
+// Transition lookahead
+// =============================================================================
+
+describe("transition lookahead", () => {
+	test("Saturday 11:40 boosts afternoon-relevant weather-current", async () => {
+		const now = saturday(11, 40)
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const items = [weatherCurrent()]
+		const result = await enhancer(items, makeContext(now))
+
+		// Weekend morning boosts weather-current by +0.5.
+		// Transition to afternoon adds +0.2 (weekend afternoon boosts weather-current).
+		expect(result.boost!["w-current"]).toBe(0.7)
+	})
+
+	test("16:40 weekday boosts evening-relevant items (weather-daily)", async () => {
+		const now = tuesday(16, 40)
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const items = [weatherDaily()]
+		const result = await enhancer(items, makeContext(now))
+
+		// Afternoon weekday doesn't boost weather-daily, but transition to evening does (+0.2)
+		expect(result.boost!["w-daily"]).toBeGreaterThan(0)
+	})
+
+	test("does not apply when far from boundary", async () => {
+		const now = tuesday(14)
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const items = [weatherDaily()]
+		const result = await enhancer(items, makeContext(now))
+
+		// Afternoon weekday doesn't boost or demote weather-daily, and no transition
+		expect(result.boost?.["w-daily"]).toBeUndefined()
+	})
+})
+
+// =============================================================================
+// Weather-time correlation
+// =============================================================================
+
+describe("weather-time correlation", () => {
+	test("morning weekday: extra boost for precipitation", async () => {
+		const now = tuesday(8)
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const rainy = weatherCurrentRainy()
+		const dry = weatherCurrent("w-dry")
+		const result = await enhancer([rainy, dry], makeContext(now))
+
+		// Both get morning boost, but rainy gets extra +0.1
+		expect(result.boost!["w-current-rain"]).toBeGreaterThan(result.boost!["w-dry"] ?? 0)
+	})
+
+	test("morning weekday: extra boost for extreme temperature", async () => {
+		const now = tuesday(8)
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const extreme = weatherCurrentExtreme()
+		const normal = weatherCurrent("w-normal")
+		const result = await enhancer([extreme, normal], makeContext(now))
+
+		expect(result.boost!["w-current-extreme"]).toBeGreaterThan(result.boost!["w-normal"] ?? 0)
+	})
+
+	test("evening with location event: extra boost for weather-current", async () => {
+		const now = tuesday(19)
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const event = calendarEvent("c1", tuesday(19, 30), { location: "The Ivy, London" })
+		const items = [weatherCurrent(), event]
+		const result = await enhancer(items, makeContext(now))
+
+		// Weather-current gets evening weather-time correlation boost (+0.2)
+		// Note: evening weekday doesn't normally boost weather-current
+		expect(result.boost!["w-current"]).toBeGreaterThan(0)
+	})
+
+	test("weather-alert always gets at least +0.5", async () => {
+		const now = tuesday(14) // afternoon — no special weather boost
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const alert = weatherAlert("w-alert", 0.5)
+		const result = await enhancer([alert], makeContext(now))
+
+		expect(result.boost!["w-alert"]).toBeGreaterThanOrEqual(0.5)
+	})
+})
+
+// =============================================================================
+// Edge cases
+// =============================================================================
+
+describe("edge cases", () => {
+	test("empty items returns empty enhancement", async () => {
+		const enhancer = createTimeOfDayEnhancer({ clock: () => tuesday(8) })
+		const result = await enhancer([], makeContext(tuesday(8)))
+
+		expect(result).toEqual({})
+	})
+
+	test("unknown item types get no boost", async () => {
+		const enhancer = createTimeOfDayEnhancer({ clock: () => tuesday(8) })
+		const result = await enhancer([unknownItem()], makeContext(tuesday(8)))
+
+		expect(result.boost?.["unknown-1"]).toBeUndefined()
+		expect(result.suppress).toBeUndefined()
+	})
+
+	test("uses context.time when no clock provided", async () => {
+		const enhancer = createTimeOfDayEnhancer()
+		const morningCtx = makeContext(tuesday(8))
+		const items = [weatherCurrent()]
+		const result = await enhancer(items, morningCtx)
+
+		// Should apply morning rules — weather-current boosted
+		expect(result.boost!["w-current"]).toBeGreaterThan(0)
+	})
+
+	test("boost values are clamped to [-1, 1]", async () => {
+		// Morning weekday: TfL alert gets +0.6 from period rules.
+		// Pre-meeting adds +0.5. Total would be +1.1 without clamping.
+		const now = tuesday(8, 45)
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const meeting = calendarEvent("c1", tuesday(9))
+		const alert = tflAlert("tfl-1", 0.8)
+		const result = await enhancer([meeting, alert], makeContext(now))
+
+		expect(result.boost!["tfl-1"]).toBeLessThanOrEqual(1)
+		expect(result.boost!["tfl-1"]).toBeGreaterThanOrEqual(-1)
+	})
+
+	test("suppress list is deduplicated", async () => {
+		// An item that would be suppressed by both evening rules and pre-meeting low-urgency
+		const now = tuesday(19, 45)
+		const enhancer = createTimeOfDayEnhancer({ clock: () => now })
+		const meeting = calendarEvent("c1", tuesday(20))
+		const ambientEvent = calendarEvent("c2", tuesday(9), {
+			signals: { urgency: 0.1, timeRelevance: TimeRelevance.Ambient },
+		})
+		const result = await enhancer([meeting, ambientEvent], makeContext(now))
+
+		if (result.suppress) {
+			const c2Count = result.suppress.filter((id) => id === "c2").length
+			expect(c2Count).toBeLessThanOrEqual(1)
+		}
+	})
+})

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

@@ -0,0 +1,595 @@
+import type { Context, FeedEnhancement, FeedItem, FeedPostProcessor } from "@aris/core"
+
+import { TimeRelevance } from "@aris/core"
+
+import type { CalDavEventData } from "@aris/source-caldav"
+import type { CalendarEventData } from "@aris/source-google-calendar"
+import type { CurrentWeatherData } from "@aris/source-weatherkit"
+
+import { CalDavFeedItemType } from "@aris/source-caldav"
+import { CalendarFeedItemType } from "@aris/source-google-calendar"
+import { TflFeedItemType } from "@aris/source-tfl"
+import { WeatherFeedItemType } from "@aris/source-weatherkit"
+
+
+export const TimePeriod = {
+	Morning: "morning",
+	Afternoon: "afternoon",
+	Evening: "evening",
+	Night: "night",
+} as const
+
+export type TimePeriod = (typeof TimePeriod)[keyof typeof TimePeriod]
+
+export const DayType = {
+	Weekday: "weekday",
+	Weekend: "weekend",
+} as const
+
+export type DayType = (typeof DayType)[keyof typeof DayType]
+
+
+const PRE_MEETING_WINDOW_MS = 30 * 60 * 1000
+const TRANSITION_WINDOW_MS = 30 * 60 * 1000
+
+const PERIOD_BOUNDARIES = [
+	{ hour: 6, period: TimePeriod.Morning },
+	{ hour: 12, period: TimePeriod.Afternoon },
+	{ hour: 17, period: TimePeriod.Evening },
+	{ hour: 22, period: TimePeriod.Night },
+] as const
+
+/** All calendar event types across sources */
+const CALENDAR_EVENT_TYPES: ReadonlySet<string> = new Set([
+	CalendarFeedItemType.Event,
+	CalDavFeedItemType.Event,
+])
+
+/**
+ * Creates a post-processor that reranks feed items based on time of day.
+ *
+ * Prioritizes items that matter right now and pushes down items that don't:
+ *
+ * - Morning: weather and first meeting rise, hourly forecasts sink.
+ *   Weekends flip — weather stays up but work calendar and commute alerts drop.
+ * - Afternoon: imminent meetings rise. Stale weather sinks.
+ * - Evening: work calendar is suppressed, tomorrow's forecast and personal
+ *   events rise. Weekends suppress work more aggressively.
+ * - Night: almost everything sinks except high-urgency alerts.
+ * - Pre-meeting (30 min before any event): that meeting dominates, low-urgency
+ *   noise is suppressed, commute/weather context rises if the meeting has a location.
+ * - Wind-down (weekday 20–22h): work items progressively sink as night approaches.
+ * - Transition lookahead (30 min before a period boundary): items relevant to
+ *   the next period get a head start.
+ * - Weather-time correlation: precipitation boosts morning weather, evening
+ *   events with locations boost current weather, alerts always stay high.
+ */
+export interface TimeOfDayEnhancerOptions {
+	/** Override clock for testing. Defaults to reading context.time. */
+	clock?: () => Date
+}
+
+export function createTimeOfDayEnhancer(options?: TimeOfDayEnhancerOptions): FeedPostProcessor {
+	const clock = options?.clock
+
+	function timeOfDayEnhancer(items: FeedItem[], context: Context): Promise<FeedEnhancement> {
+		if (items.length === 0) return Promise.resolve({})
+
+		const now = clock ? clock() : context.time
+		const period = getTimePeriod(now)
+		const dayType = getDayType(now)
+		const boost: Record<string, number> = {}
+		const suppress: string[] = []
+
+		// 1. Apply period-based rules
+		const firstEventId = findFirstEventOfDay(items, now)
+
+		switch (period) {
+			case TimePeriod.Morning:
+				if (dayType === DayType.Weekday) {
+					applyMorningWeekday(items, boost, firstEventId)
+				} else {
+					applyMorningWeekend(items, boost)
+				}
+				break
+			case TimePeriod.Afternoon:
+				if (dayType === DayType.Weekday) {
+					applyAfternoonWeekday(items, boost)
+				} else {
+					applyAfternoonWeekend(items, boost)
+				}
+				break
+			case TimePeriod.Evening:
+				if (dayType === DayType.Weekday) {
+					applyEveningWeekday(items, boost, suppress)
+				} else {
+					applyEveningWeekend(items, boost, suppress)
+				}
+				break
+			case TimePeriod.Night:
+				applyNight(items, boost, suppress)
+				break
+		}
+
+		// 2. Pre-meeting overrides (can override period rules)
+		const preMeeting = detectPreMeetingItems(items, now)
+		applyPreMeetingOverrides(items, preMeeting, boost, suppress)
+
+		// 3. Wind-down gradient
+		applyWindDown(items, now, dayType, boost)
+
+		// 4. Transition lookahead
+		applyTransitionLookahead(items, now, period, dayType, boost)
+
+		// 5. Weather-time correlation
+		const eveningLocation = hasEveningCalendarEventWithLocation(items, now)
+		applyWeatherTimeCorrelation(items, period, dayType, eveningLocation, boost)
+
+		// Clamp boost values to [-1, 1] — additive layers can exceed the range
+		for (const id in boost) {
+			boost[id] = Math.max(-1, Math.min(1, boost[id]!))
+		}
+
+		const result: FeedEnhancement = {}
+		if (Object.keys(boost).length > 0) {
+			result.boost = boost
+		}
+		const uniqueSuppress = [...new Set(suppress)]
+		if (uniqueSuppress.length > 0) {
+			result.suppress = uniqueSuppress
+		}
+		return Promise.resolve(result)
+	}
+
+	return timeOfDayEnhancer
+}
+
+
+export function getTimePeriod(date: Date): TimePeriod {
+	const hour = date.getHours()
+	if (hour >= 22 || hour < 6) return TimePeriod.Night
+	if (hour >= 17) return TimePeriod.Evening
+	if (hour >= 12) return TimePeriod.Afternoon
+	return TimePeriod.Morning
+}
+
+export function getDayType(date: Date): DayType {
+	const day = date.getDay()
+	return day === 0 || day === 6 ? DayType.Weekend : DayType.Weekday
+}
+
+/**
+ * Returns the next period boundary as { hour, period } and the ms until it.
+ */
+function getNextPeriodBoundary(date: Date): { period: TimePeriod; msUntil: number } {
+	const hour = date.getHours()
+	const minuteMs = date.getMinutes() * 60_000 + date.getSeconds() * 1000 + date.getMilliseconds()
+
+	for (const boundary of PERIOD_BOUNDARIES) {
+		if (hour < boundary.hour) {
+			const msUntil = (boundary.hour - hour) * 3_600_000 - minuteMs
+			return { period: boundary.period, msUntil }
+		}
+	}
+
+	// Past 22:00 — next boundary is morning at 06:00
+	const hoursUntil6 = (24 - hour + 6) * 3_600_000 - minuteMs
+	return { period: TimePeriod.Morning, msUntil: hoursUntil6 }
+}
+
+/**
+ * Extract start time from calendar event data.
+ * Google Calendar uses `startTime`, CalDAV uses `startDate`.
+ */
+function getEventStartTime(data: CalendarEventData | CalDavEventData): Date {
+	return "startTime" in data ? (data as CalendarEventData).startTime : (data as CalDavEventData).startDate
+}
+
+/**
+ * Check if a current weather item indicates precipitation or extreme conditions.
+ * Only meaningful for weather-current items.
+ */
+function hasPrecipitationOrExtreme(item: FeedItem): boolean {
+	const data = item.data as CurrentWeatherData
+	if (data.precipitationIntensity > 0) return true
+	if (data.temperature < 0 || data.temperature > 35) return true
+	return false
+}
+
+
+interface PreMeetingInfo {
+	/** IDs of calendar items starting within the pre-meeting window */
+	upcomingMeetingIds: Set<string>
+	/** Whether any upcoming meeting has a location */
+	hasLocationMeeting: boolean
+}
+
+function detectPreMeetingItems(items: FeedItem[], now: Date): PreMeetingInfo {
+	const nowMs = now.getTime()
+	const upcomingMeetingIds = new Set<string>()
+	let hasLocationMeeting = false
+
+	for (const item of items) {
+		if (!CALENDAR_EVENT_TYPES.has(item.type)) continue
+
+		const data = item.data as CalendarEventData | CalDavEventData
+		const msUntil = getEventStartTime(data).getTime() - nowMs
+		if (msUntil > 0 && msUntil <= PRE_MEETING_WINDOW_MS) {
+			upcomingMeetingIds.add(item.id)
+			if (data.location) {
+				hasLocationMeeting = true
+			}
+		}
+	}
+
+	return { upcomingMeetingIds, hasLocationMeeting }
+}
+
+
+function findFirstEventOfDay(items: FeedItem[], now: Date): string | null {
+	let earliest: { id: string; time: number } | null = null
+
+	for (const item of items) {
+		if (!CALENDAR_EVENT_TYPES.has(item.type)) continue
+
+		const data = item.data as CalendarEventData | CalDavEventData
+		const startTime = getEventStartTime(data)
+		const startMs = startTime.getTime()
+
+		// Must be today and in the future
+		const sameDay =
+			startTime.getFullYear() === now.getFullYear() &&
+			startTime.getMonth() === now.getMonth() &&
+			startTime.getDate() === now.getDate()
+		if (!sameDay) continue
+		if (startMs <= now.getTime()) continue
+
+		if (!earliest || startMs < earliest.time) {
+			earliest = { id: item.id, time: startMs }
+		}
+	}
+
+	return earliest?.id ?? null
+}
+
+
+function applyMorningWeekday(
+	items: FeedItem[],
+	boost: Record<string, number>,
+	firstEventId: string | null,
+): void {
+	for (const item of items) {
+		switch (item.type) {
+			case WeatherFeedItemType.Current:
+				boost[item.id] = (boost[item.id] ?? 0) + 0.7
+				break
+			case WeatherFeedItemType.Alert:
+				boost[item.id] = (boost[item.id] ?? 0) + 0.8
+				break
+			case WeatherFeedItemType.Hourly:
+			case WeatherFeedItemType.Daily:
+				boost[item.id] = (boost[item.id] ?? 0) - 0.3
+				break
+			case TflFeedItemType.Alert:
+				boost[item.id] = (boost[item.id] ?? 0) + 0.6
+				break
+		}
+	}
+
+	if (firstEventId) {
+		boost[firstEventId] = (boost[firstEventId] ?? 0) + 0.6
+	}
+}
+
+function applyMorningWeekend(items: FeedItem[], boost: Record<string, number>): void {
+	for (const item of items) {
+		switch (item.type) {
+			case WeatherFeedItemType.Current:
+				boost[item.id] = (boost[item.id] ?? 0) + 0.5
+				break
+			case WeatherFeedItemType.Daily:
+				boost[item.id] = (boost[item.id] ?? 0) + 0.4
+				break
+			case CalendarFeedItemType.Event:
+			case CalDavFeedItemType.Event:
+				boost[item.id] = (boost[item.id] ?? 0) - 0.4
+				break
+			case TflFeedItemType.Alert:
+				boost[item.id] = (boost[item.id] ?? 0) - 0.3
+				break
+		}
+	}
+}
+
+function applyAfternoonWeekday(items: FeedItem[], boost: Record<string, number>): void {
+	for (const item of items) {
+		switch (item.type) {
+			case CalendarFeedItemType.Event:
+			case CalDavFeedItemType.Event:
+				if (item.signals?.timeRelevance === TimeRelevance.Imminent) {
+					boost[item.id] = (boost[item.id] ?? 0) + 0.5
+				}
+				break
+			case WeatherFeedItemType.Current:
+			case WeatherFeedItemType.Hourly:
+				boost[item.id] = (boost[item.id] ?? 0) - 0.2
+				break
+		}
+	}
+}
+
+function applyAfternoonWeekend(items: FeedItem[], boost: Record<string, number>): void {
+	for (const item of items) {
+		switch (item.type) {
+			case WeatherFeedItemType.Current:
+				boost[item.id] = (boost[item.id] ?? 0) + 0.3
+				break
+			case CalendarFeedItemType.Event:
+			case CalDavFeedItemType.Event:
+				boost[item.id] = (boost[item.id] ?? 0) - 0.5
+				break
+			case TflFeedItemType.Alert:
+				boost[item.id] = (boost[item.id] ?? 0) - 0.2
+				break
+		}
+	}
+}
+
+function applyEveningWeekday(
+	items: FeedItem[],
+	boost: Record<string, number>,
+	suppress: string[],
+): void {
+	for (const item of items) {
+		switch (item.type) {
+			case CalendarFeedItemType.Event:
+			case CalDavFeedItemType.Event:
+				if (item.signals?.timeRelevance === TimeRelevance.Ambient) {
+					suppress.push(item.id)
+				}
+				break
+			case TflFeedItemType.Alert:
+				boost[item.id] = (boost[item.id] ?? 0) - 0.4
+				break
+			case WeatherFeedItemType.Daily:
+				boost[item.id] = (boost[item.id] ?? 0) + 0.3
+				break
+			case CalendarFeedItemType.AllDay:
+				boost[item.id] = (boost[item.id] ?? 0) + 0.3
+				break
+		}
+	}
+}
+
+function applyEveningWeekend(
+	items: FeedItem[],
+	boost: Record<string, number>,
+	suppress: string[],
+): void {
+	for (const item of items) {
+		switch (item.type) {
+			case WeatherFeedItemType.Current:
+				boost[item.id] = (boost[item.id] ?? 0) + 0.3
+				break
+			case CalendarFeedItemType.Event:
+			case CalDavFeedItemType.Event:
+				if (item.signals?.timeRelevance === TimeRelevance.Ambient) {
+					suppress.push(item.id)
+				}
+				break
+			case TflFeedItemType.Alert:
+				boost[item.id] = (boost[item.id] ?? 0) - 0.5
+				break
+		}
+	}
+}
+
+function applyNight(items: FeedItem[], boost: Record<string, number>, suppress: string[]): void {
+	for (const item of items) {
+		// Suppress all ambient items
+		if (item.signals?.timeRelevance === TimeRelevance.Ambient) {
+			suppress.push(item.id)
+			continue
+		}
+
+		// High-urgency alerts survive unboosted
+		if (
+			(item.type === WeatherFeedItemType.Alert || item.type === TflFeedItemType.Alert) &&
+			(item.signals?.urgency ?? 0) >= 0.8
+		) {
+			continue
+		}
+
+		// Demote everything else
+		switch (item.type) {
+			case CalendarFeedItemType.Event:
+			case CalendarFeedItemType.AllDay:
+			case CalDavFeedItemType.Event:
+				boost[item.id] = (boost[item.id] ?? 0) - 0.6
+				break
+			case WeatherFeedItemType.Current:
+			case WeatherFeedItemType.Hourly:
+				boost[item.id] = (boost[item.id] ?? 0) - 0.5
+				break
+		}
+	}
+}
+
+
+function applyPreMeetingOverrides(
+	items: FeedItem[],
+	preMeeting: PreMeetingInfo,
+	boost: Record<string, number>,
+	suppress: string[],
+): void {
+	if (preMeeting.upcomingMeetingIds.size === 0) return
+
+	// Intentional override, not additive — the upcoming meeting should dominate
+	// regardless of what period rules assigned. Don't reorder this before period rules.
+	for (const meetingId of preMeeting.upcomingMeetingIds) {
+		boost[meetingId] = 0.9
+	}
+
+	for (const item of items) {
+		if (preMeeting.upcomingMeetingIds.has(item.id)) continue
+
+		switch (item.type) {
+			case TflFeedItemType.Alert:
+				boost[item.id] = (boost[item.id] ?? 0) + 0.5
+				break
+			case WeatherFeedItemType.Current:
+				if (preMeeting.hasLocationMeeting) {
+					boost[item.id] = (boost[item.id] ?? 0) + 0.4
+				}
+				break
+		}
+
+		// Suppress items that explicitly declare low urgency.
+		// Items without signals are left alone — absence of urgency is not low urgency.
+		if (item.signals && item.signals.urgency !== undefined && item.signals.urgency < 0.3) {
+			suppress.push(item.id)
+		}
+	}
+}
+
+function applyWindDown(
+	items: FeedItem[],
+	now: Date,
+	dayType: DayType,
+	boost: Record<string, number>,
+): void {
+	if (dayType !== DayType.Weekday) return
+
+	const hour = now.getHours()
+	const minutes = now.getMinutes()
+
+	if (hour < 20 || hour >= 22) return
+
+	// Gradient: 20:00 → -0.1, 21:00 → -0.2, 21:30+ → -0.3
+	let additionalDemotion: number
+	if (hour === 20) {
+		additionalDemotion = -0.1
+	} else if (hour === 21 && minutes < 30) {
+		additionalDemotion = -0.2
+	} else {
+		additionalDemotion = -0.3
+	}
+
+	for (const item of items) {
+		switch (item.type) {
+			case CalendarFeedItemType.Event:
+			case CalendarFeedItemType.AllDay:
+			case CalDavFeedItemType.Event:
+			case TflFeedItemType.Alert:
+				boost[item.id] = (boost[item.id] ?? 0) + additionalDemotion
+				break
+		}
+	}
+}
+
+
+function applyTransitionLookahead(
+	items: FeedItem[],
+	now: Date,
+	currentPeriod: TimePeriod,
+	dayType: DayType,
+	boost: Record<string, number>,
+): void {
+	const next = getNextPeriodBoundary(now)
+	if (next.msUntil > TRANSITION_WINDOW_MS) return
+
+	// Apply a +0.2 secondary boost to items that would be boosted in the next period
+	const nextPeriodBoost = getNextPeriodBoostTargets(next.period, dayType)
+
+	for (const item of items) {
+		if (nextPeriodBoost.has(item.type)) {
+			boost[item.id] = (boost[item.id] ?? 0) + 0.2
+		}
+	}
+}
+
+/**
+ * Returns the set of item types that get boosted in a given period+dayType.
+ */
+function getNextPeriodBoostTargets(period: TimePeriod, dayType: DayType): ReadonlySet<string> {
+	const targets = new Set<string>()
+
+	switch (period) {
+		case TimePeriod.Morning:
+			targets.add(WeatherFeedItemType.Current)
+			if (dayType === DayType.Weekday) {
+				targets.add(WeatherFeedItemType.Alert)
+				targets.add(TflFeedItemType.Alert)
+			} else {
+				targets.add(WeatherFeedItemType.Daily)
+			}
+			break
+		case TimePeriod.Afternoon:
+			if (dayType === DayType.Weekend) {
+				targets.add(WeatherFeedItemType.Current)
+			}
+			break
+		case TimePeriod.Evening:
+			targets.add(WeatherFeedItemType.Daily)
+			if (dayType === DayType.Weekend) {
+				targets.add(WeatherFeedItemType.Current)
+			}
+			break
+		case TimePeriod.Night:
+			// Night doesn't boost much — transition toward night means demoting,
+			// which is handled by wind-down. No positive targets here.
+			break
+	}
+
+	return targets
+}
+
+
+function applyWeatherTimeCorrelation(
+	items: FeedItem[],
+	period: TimePeriod,
+	dayType: DayType,
+	hasEveningEventWithLocation: boolean,
+	boost: Record<string, number>,
+): void {
+	for (const item of items) {
+		switch (item.type) {
+			case WeatherFeedItemType.Alert: {
+				const current = boost[item.id] ?? 0
+				if (current < 0.5) {
+					boost[item.id] = 0.5
+				}
+				break
+			}
+			case WeatherFeedItemType.Current:
+				if (period === TimePeriod.Morning && dayType === DayType.Weekday && hasPrecipitationOrExtreme(item)) {
+					boost[item.id] = (boost[item.id] ?? 0) + 0.1
+				}
+				if (period === TimePeriod.Evening && hasEveningEventWithLocation) {
+					boost[item.id] = (boost[item.id] ?? 0) + 0.2
+				}
+				break
+		}
+	}
+}
+
+function hasEveningCalendarEventWithLocation(items: FeedItem[], now: Date): boolean {
+	const todayEvening17 = new Date(now)
+	todayEvening17.setHours(17, 0, 0, 0)
+	const todayNight22 = new Date(now)
+	todayNight22.setHours(22, 0, 0, 0)
+
+	for (const item of items) {
+		if (!CALENDAR_EVENT_TYPES.has(item.type)) continue
+
+		const data = item.data as CalendarEventData | CalDavEventData
+		const startMs = getEventStartTime(data).getTime()
+		if (startMs >= todayEvening17.getTime() && startMs < todayNight22.getTime()) {
+			if (data.location) return true
+		}
+	}
+
+	return false
+}
+
+

packages/aris-source-caldav/scripts/test-live.ts

@@ -5,6 +5,8 @@
  *   bun run test-live.ts
  */
 
+import { Context } from "@aris/core"
+
 import { CalDavSource } from "../src/index.ts"
 
 const serverUrl = prompt("CalDAV server URL:")
@@ -27,7 +29,7 @@ const source = new CalDavSource({
 	lookAheadDays,
 })
 
-const context = { time: new Date() }
+const context = new Context()
 
 console.log(`\nFetching from ${serverUrl} as ${username} (lookAheadDays=${lookAheadDays})...\n`)
 

packages/aris-source-caldav/src/caldav-source.test.ts

@@ -1,6 +1,6 @@
-import type { Context } from "@aris/core"
+import type { ContextEntry } from "@aris/core"
 
-import { TimeRelevance, contextValue } from "@aris/core"
+import { Context, TimeRelevance } from "@aris/core"
 import { describe, expect, test } from "bun:test"
 import { readFileSync } from "node:fs"
 import { join } from "node:path"
@@ -13,14 +13,21 @@ import type {
 } from "./types.ts"
 
 import { CalDavSource, computeSignals } from "./caldav-source.ts"
-import { CalDavCalendarKey } from "./calendar-context.ts"
+import { CalDavCalendarKey, type CalendarContext } from "./calendar-context.ts"
 
 function loadFixture(name: string): string {
 	return readFileSync(join(import.meta.dir, "..", "fixtures", name), "utf-8")
 }
 
 function createContext(time: Date): Context {
-	return { time }
+	return new Context(time)
+}
+
+/** Extract the CalendarContext value from fetchContext entries. */
+function extractCalendar(entries: readonly ContextEntry[] | null): CalendarContext | undefined {
+	if (!entries) return undefined
+	const entry = entries.find(([key]) => key === CalDavCalendarKey)
+	return entry?.[1] as CalendarContext | undefined
 }
 
 class MockDAVClient implements CalDavDAVClient {
@@ -302,8 +309,8 @@ describe("CalDavSource.fetchContext", () => {
 	test("returns empty context when no calendars exist", async () => {
 		const client = new MockDAVClient([], {})
 		const source = createSource(client)
-		const ctx = await source.fetchContext(createContext(new Date("2026-01-15T12:00:00Z")))
-		const calendar = contextValue(ctx as Context, CalDavCalendarKey)
+		const entries = await source.fetchContext(createContext(new Date("2026-01-15T12:00:00Z")))
+		const calendar = extractCalendar(entries)
 
 		expect(calendar).toBeDefined()
 		expect(calendar!.inProgress).toEqual([])
@@ -320,8 +327,8 @@ describe("CalDavSource.fetchContext", () => {
 		const source = createSource(client)
 
 		// 14:30 is during the 14:00-15:00 event
-		const ctx = await source.fetchContext(createContext(new Date("2026-01-15T14:30:00Z")))
-		const calendar = contextValue(ctx as Context, CalDavCalendarKey)
+		const entries = await source.fetchContext(createContext(new Date("2026-01-15T14:30:00Z")))
+		const calendar = extractCalendar(entries)
 
 		expect(calendar!.inProgress).toHaveLength(1)
 		expect(calendar!.inProgress[0]!.title).toBe("Team Standup")
@@ -335,8 +342,8 @@ describe("CalDavSource.fetchContext", () => {
 		const source = createSource(client)
 
 		// 12:00 is before the 14:00 event
-		const ctx = await source.fetchContext(createContext(new Date("2026-01-15T12:00:00Z")))
-		const calendar = contextValue(ctx as Context, CalDavCalendarKey)
+		const entries = await source.fetchContext(createContext(new Date("2026-01-15T12:00:00Z")))
+		const calendar = extractCalendar(entries)
 
 		expect(calendar!.inProgress).toHaveLength(0)
 		expect(calendar!.nextEvent).not.toBeNull()
@@ -350,8 +357,8 @@ describe("CalDavSource.fetchContext", () => {
 		const client = new MockDAVClient([{ url: "/cal/work", displayName: "Work" }], objects)
 		const source = createSource(client)
 
-		const ctx = await source.fetchContext(createContext(new Date("2026-01-15T12:00:00Z")))
-		const calendar = contextValue(ctx as Context, CalDavCalendarKey)
+		const entries = await source.fetchContext(createContext(new Date("2026-01-15T12:00:00Z")))
+		const calendar = extractCalendar(entries)
 
 		expect(calendar!.inProgress).toHaveLength(0)
 		expect(calendar!.nextEvent).toBeNull()
@@ -369,8 +376,8 @@ describe("CalDavSource.fetchContext", () => {
 		const client = new MockDAVClient([{ url: "/cal/work", displayName: "Work" }], objects)
 		const source = createSource(client)
 
-		const ctx = await source.fetchContext(createContext(new Date("2026-01-15T12:00:00Z")))
-		const calendar = contextValue(ctx as Context, CalDavCalendarKey)
+		const entries = await source.fetchContext(createContext(new Date("2026-01-15T12:00:00Z")))
+		const calendar = extractCalendar(entries)
 
 		expect(calendar!.todayEventCount).toBe(2)
 		expect(calendar!.hasTodayEvents).toBe(true)

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

@@ -1,13 +1,13 @@
-import type { ActionDefinition, Context, FeedItemSignals, FeedSource } from "@aris/core"
+import type { ActionDefinition, ContextEntry, FeedItemSignals, FeedSource } from "@aris/core"
 
-import { TimeRelevance, UnknownActionError } from "@aris/core"
+import { Context, TimeRelevance, UnknownActionError } from "@aris/core"
 import { DAVClient } from "tsdav"
 
 import type { CalDavDAVClient, CalDavEventData, CalDavFeedItem } from "./types.ts"
-import { CalDavEventStatus } from "./types.ts"
 
 import { CalDavCalendarKey, type CalendarContext } from "./calendar-context.ts"
 import { parseICalEvents } from "./ical-parser.ts"
+import { CalDavEventStatus, CalDavFeedItemType } from "./types.ts"
 
 // -- Source options --
 
@@ -93,17 +93,20 @@ export class CalDavSource implements FeedSource<CalDavFeedItem> {
 		throw new UnknownActionError(actionId)
 	}
 
-	async fetchContext(context: Context): Promise<Partial<Context> | null> {
+	async fetchContext(context: Context): Promise<readonly ContextEntry[] | null> {
 		const events = await this.fetchEvents(context)
 		if (events.length === 0) {
-			return {
-				[CalDavCalendarKey]: {
-					inProgress: [],
-					nextEvent: null,
-					hasTodayEvents: false,
-					todayEventCount: 0,
-				},
-			}
+			return [
+				[
+					CalDavCalendarKey,
+					{
+						inProgress: [],
+						nextEvent: null,
+						hasTodayEvents: false,
+						todayEventCount: 0,
+					},
+				],
+			]
 		}
 
 		const now = context.time
@@ -121,7 +124,7 @@ export class CalDavSource implements FeedSource<CalDavFeedItem> {
 			todayEventCount: events.length,
 		}
 
-		return { [CalDavCalendarKey]: calendarContext }
+		return [[CalDavCalendarKey, calendarContext]]
 	}
 
 	async fetchItems(context: Context): Promise<CalDavFeedItem[]> {
@@ -340,7 +343,7 @@ export function computeSignals(
 function createFeedItem(event: CalDavEventData, now: Date, timeZone?: string): CalDavFeedItem {
 	return {
 		id: `caldav-event-${event.uid}${event.recurrenceId ? `-${event.recurrenceId}` : ""}`,
-		type: "caldav-event",
+		type: CalDavFeedItemType.Event,
 		timestamp: now,
 		data: event,
 		signals: computeSignals(event, now, timeZone),

packages/aris-source-caldav/src/calendar-context.ts

@@ -21,4 +21,4 @@ export interface CalendarContext {
 	todayEventCount: number
 }
 
-export const CalDavCalendarKey: ContextKey<CalendarContext> = contextKey("caldavCalendar")
+export const CalDavCalendarKey: ContextKey<CalendarContext> = contextKey("aris.caldav", "calendar")

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

@@ -5,6 +5,7 @@ export {
 	AttendeeRole,
 	AttendeeStatus,
 	CalDavEventStatus,
+	CalDavFeedItemType,
 	type CalDavAlarm,
 	type CalDavAttendee,
 	type CalDavDAVCalendar,

packages/aris-source-caldav/src/types.ts

@@ -64,9 +64,17 @@ export interface CalDavEventData extends Record<string, unknown> {
 	recurrenceId: string | null
 }
 
+// -- Feed item type --
+
+export const CalDavFeedItemType = {
+	Event: "caldav-event",
+} as const
+
+export type CalDavFeedItemType = (typeof CalDavFeedItemType)[keyof typeof CalDavFeedItemType]
+
 // -- Feed item --
 
-export type CalDavFeedItem = FeedItem<"caldav-event", CalDavEventData>
+export type CalDavFeedItem = FeedItem<typeof CalDavFeedItemType.Event, CalDavEventData>
 
 // -- DAV client interface --
 

packages/aris-source-google-calendar/src/calendar-context.ts

@@ -10,4 +10,4 @@ export interface NextEvent {
 	location: string | null
 }
 
-export const NextEventKey: ContextKey<NextEvent> = contextKey("nextEvent")
+export const NextEventKey: ContextKey<NextEvent> = contextKey("aris.google-calendar", "nextEvent")

packages/aris-source-google-calendar/src/feed-items.ts

@@ -3,19 +3,19 @@ import type { FeedItem } from "@aris/core"
 import type { CalendarEventData } from "./types"
 
 export const CalendarFeedItemType = {
-	event: "calendar-event",
-	allDay: "calendar-all-day",
+	Event: "calendar-event",
+	AllDay: "calendar-all-day",
 } as const
 
 export type CalendarFeedItemType = (typeof CalendarFeedItemType)[keyof typeof CalendarFeedItemType]
 
 export interface CalendarEventFeedItem extends FeedItem<
-	typeof CalendarFeedItemType.event,
+	typeof CalendarFeedItemType.Event,
 	CalendarEventData
 > {}
 
 export interface CalendarAllDayFeedItem extends FeedItem<
-	typeof CalendarFeedItemType.allDay,
+	typeof CalendarFeedItemType.AllDay,
 	CalendarEventData
 > {}
 

packages/aris-source-google-calendar/src/google-calendar-source.test.ts

@@ -1,10 +1,10 @@
-import { TimeRelevance, contextValue, type Context } from "@aris/core"
+import { Context, TimeRelevance } from "@aris/core"
 import { describe, expect, test } from "bun:test"
 
 import type { ApiCalendarEvent, GoogleCalendarClient, ListEventsOptions } from "./types"
 
 import fixture from "../fixtures/events.json"
-import { NextEventKey } from "./calendar-context"
+import { NextEventKey, type NextEvent } from "./calendar-context"
 import { CalendarFeedItemType } from "./feed-items"
 import { GoogleCalendarSource } from "./google-calendar-source"
 
@@ -38,7 +38,7 @@ function defaultMockClient(): GoogleCalendarClient {
 }
 
 function createContext(time?: Date): Context {
-	return { time: time ?? NOW }
+	return new Context(time ?? NOW)
 }
 
 describe("GoogleCalendarSource", () => {
@@ -69,7 +69,7 @@ describe("GoogleCalendarSource", () => {
 			const source = new GoogleCalendarSource({ client: defaultMockClient() })
 			const items = await source.fetchItems(createContext())
 
-			const timedItems = items.filter((i) => i.type === CalendarFeedItemType.event)
+			const timedItems = items.filter((i) => i.type === CalendarFeedItemType.Event)
 			expect(timedItems.length).toBe(4)
 		})
 
@@ -77,7 +77,7 @@ describe("GoogleCalendarSource", () => {
 			const source = new GoogleCalendarSource({ client: defaultMockClient() })
 			const items = await source.fetchItems(createContext())
 
-			const allDayItems = items.filter((i) => i.type === CalendarFeedItemType.allDay)
+			const allDayItems = items.filter((i) => i.type === CalendarFeedItemType.AllDay)
 			expect(allDayItems.length).toBe(1)
 		})
 
@@ -229,15 +229,16 @@ describe("GoogleCalendarSource", () => {
 
 		test("returns next upcoming timed event (not ongoing)", async () => {
 			const source = new GoogleCalendarSource({ client: defaultMockClient() })
-			const result = await source.fetchContext(createContext())
+			const entries = await source.fetchContext(createContext())
 
-			expect(result).not.toBeNull()
-			const nextEvent = contextValue(result! as Context, NextEventKey)
-			expect(nextEvent).toBeDefined()
+			expect(entries).not.toBeNull()
+			expect(entries).toHaveLength(1)
+			const [key, nextEvent] = entries![0]! as [typeof NextEventKey, NextEvent]
+			expect(key).toEqual(NextEventKey)
 			// evt-soon starts at 10:10, which is the nearest future timed event
-			expect(nextEvent!.title).toBe("1:1 with Manager")
-			expect(nextEvent!.minutesUntilStart).toBe(10)
-			expect(nextEvent!.location).toBeNull()
+			expect(nextEvent.title).toBe("1:1 with Manager")
+			expect(nextEvent.minutesUntilStart).toBe(10)
+			expect(nextEvent.location).toBeNull()
 		})
 
 		test("includes location when available", async () => {
@@ -255,12 +256,11 @@ describe("GoogleCalendarSource", () => {
 			const source = new GoogleCalendarSource({
 				client: createMockClient({ primary: events }),
 			})
-			const result = await source.fetchContext(createContext())
+			const entries = await source.fetchContext(createContext())
 
-			expect(result).not.toBeNull()
-			const nextEvent = contextValue(result! as Context, NextEventKey)
-			expect(nextEvent).toBeDefined()
-			expect(nextEvent!.location).toBe("123 Main St")
+			expect(entries).not.toBeNull()
+			const [, nextEvent] = entries![0]! as [typeof NextEventKey, NextEvent]
+			expect(nextEvent.location).toBe("123 Main St")
 		})
 
 		test("skips ongoing events for next-event context", async () => {

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

@@ -1,6 +1,6 @@
-import type { ActionDefinition, Context, FeedItemSignals, FeedSource } from "@aris/core"
+import type { ActionDefinition, ContextEntry, FeedItemSignals, FeedSource } from "@aris/core"
 
-import { TimeRelevance, UnknownActionError } from "@aris/core"
+import { Context, TimeRelevance, UnknownActionError } from "@aris/core"
 
 import type {
 	ApiCalendarEvent,
@@ -58,7 +58,7 @@ const URGENCY_ALL_DAY = 0.4
  *   .register(calendarSource)
  *
  * // Access next-event context in downstream sources
- * const next = contextValue(context, NextEventKey)
+ * const next = context.get(NextEventKey)
  * if (next && next.minutesUntilStart < 15) {
  *   // remind user
  * }
@@ -85,7 +85,7 @@ export class GoogleCalendarSource implements FeedSource<CalendarFeedItem> {
 		throw new UnknownActionError(actionId)
 	}
 
-	async fetchContext(context: Context): Promise<Partial<Context> | null> {
+	async fetchContext(context: Context): Promise<readonly ContextEntry[] | null> {
 		const events = await this.fetchAllEvents(context.time)
 
 		const now = context.time.getTime()
@@ -105,7 +105,7 @@ export class GoogleCalendarSource implements FeedSource<CalendarFeedItem> {
 			location: nextTimedEvent.location,
 		}
 
-		return { [NextEventKey]: nextEvent }
+		return [[NextEventKey, nextEvent]]
 	}
 
 	async fetchItems(context: Context): Promise<CalendarFeedItem[]> {
@@ -209,7 +209,7 @@ function createFeedItem(
 	nowMs: number,
 	lookaheadMs: number,
 ): CalendarFeedItem {
-	const itemType = event.isAllDay ? CalendarFeedItemType.allDay : CalendarFeedItemType.event
+	const itemType = event.isAllDay ? CalendarFeedItemType.AllDay : CalendarFeedItemType.Event
 
 	return {
 		id: `calendar-${event.calendarId}-${event.eventId}`,

packages/aris-source-google-calendar/src/index.ts

@@ -1,7 +1,6 @@
 export { NextEventKey, type NextEvent } from "./calendar-context"
 export {
 	CalendarFeedItemType,
-	type CalendarFeedItemType as CalendarFeedItemTypeType,
 	type CalendarAllDayFeedItem,
 	type CalendarEventFeedItem,
 	type CalendarFeedItem,
@@ -10,7 +9,6 @@ export { DefaultGoogleCalendarClient } from "./google-calendar-api"
 export { GoogleCalendarSource, type GoogleCalendarSourceOptions } from "./google-calendar-source"
 export {
 	EventStatus,
-	type EventStatus as EventStatusType,
 	type ApiCalendarEvent,
 	type ApiEventDateTime,
 	type CalendarEventData,

packages/aris-source-location/src/location-source.test.ts

@@ -1,6 +1,8 @@
 import { describe, expect, mock, test } from "bun:test"
 
-import { LocationKey, LocationSource, type Location } from "./location-source.ts"
+import type { Location } from "./types.ts"
+
+import { LocationKey, LocationSource } from "./location-source.ts"
 
 function createLocation(overrides: Partial<Location> = {}): Location {
 	return {
@@ -39,8 +41,8 @@ describe("LocationSource", () => {
 			const location = createLocation()
 			source.pushLocation(location)
 
-			const context = await source.fetchContext()
-			expect(context).toEqual({ [LocationKey]: location })
+			const entries = await source.fetchContext()
+			expect(entries).toEqual([[LocationKey, location]])
 		})
 	})
 
@@ -65,7 +67,7 @@ describe("LocationSource", () => {
 			source.pushLocation(location)
 
 			expect(listener).toHaveBeenCalledTimes(1)
-			expect(listener).toHaveBeenCalledWith({ [LocationKey]: location })
+			expect(listener).toHaveBeenCalledWith([[LocationKey, location]])
 		})
 	})
 

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

@@ -1,11 +1,11 @@
-import type { ActionDefinition, Context, FeedSource } from "@aris/core"
+import type { ActionDefinition, ContextEntry, FeedSource } from "@aris/core"
 
-import { UnknownActionError, contextKey, type ContextKey } from "@aris/core"
+import { Context, UnknownActionError, contextKey, type ContextKey } from "@aris/core"
 import { type } from "arktype"
 
 import { Location, type LocationSourceOptions } from "./types.ts"
 
-export const LocationKey: ContextKey<Location> = contextKey("location")
+export const LocationKey: ContextKey<Location> = contextKey("aris.location", "location")
 
 /**
  * A FeedSource that provides location context.
@@ -20,7 +20,7 @@ export class LocationSource implements FeedSource {
 
 	private readonly historySize: number
 	private locations: Location[] = []
-	private listeners = new Set<(update: Partial<Context>) => void>()
+	private listeners = new Set<(entries: readonly ContextEntry[]) => void>()
 
 	constructor(options: LocationSourceOptions = {}) {
 		this.historySize = options.historySize ?? 1
@@ -59,8 +59,9 @@ export class LocationSource implements FeedSource {
 		if (this.locations.length > this.historySize) {
 			this.locations.shift()
 		}
+		const entries: readonly ContextEntry[] = [[LocationKey, location]]
 		this.listeners.forEach((listener) => {
-			listener({ [LocationKey]: location })
+			listener(entries)
 		})
 	}
 
@@ -78,16 +79,16 @@ export class LocationSource implements FeedSource {
 		return this.locations
 	}
 
-	onContextUpdate(callback: (update: Partial<Context>) => void): () => void {
+	onContextUpdate(callback: (entries: readonly ContextEntry[]) => void): () => void {
 		this.listeners.add(callback)
 		return () => {
 			this.listeners.delete(callback)
 		}
 	}
 
-	async fetchContext(): Promise<Partial<Context> | null> {
+	async fetchContext(): Promise<readonly ContextEntry[] | null> {
 		if (this.lastLocation) {
-			return { [LocationKey]: this.lastLocation }
+			return [[LocationKey, this.lastLocation]]
 		}
 		return null
 	}

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

@@ -1,12 +1,13 @@
 export { TflSource } from "./tfl-source.ts"
 export { TflApi } from "./tfl-api.ts"
 export type { TflLineId } from "./tfl-api.ts"
-export type {
-	ITflApi,
-	StationLocation,
-	TflAlertData,
-	TflAlertFeedItem,
-	TflAlertSeverity,
-	TflLineStatus,
-	TflSourceOptions,
+export {
+	TflFeedItemType,
+	type ITflApi,
+	type StationLocation,
+	type TflAlertData,
+	type TflAlertFeedItem,
+	type TflAlertSeverity,
+	type TflLineStatus,
+	type TflSourceOptions,
 } from "./types.ts"

packages/aris-source-tfl/src/tfl-source.test.ts

@@ -1,5 +1,4 @@
-import type { Context } from "@aris/core"
-
+import { Context } from "@aris/core"
 import { LocationKey, type Location } from "@aris/source-location"
 import { describe, expect, test } from "bun:test"
 
@@ -81,9 +80,9 @@ class FixtureTflApi implements ITflApi {
 }
 
 function createContext(location?: Location): Context {
-	const ctx: Context = { time: new Date("2026-01-15T12:00:00Z") }
+	const ctx = new Context(new Date("2026-01-15T12:00:00Z"))
 	if (location) {
-		ctx[LocationKey] = location
+		ctx.set([[LocationKey, location]])
 	}
 	return ctx
 }

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

@@ -1,6 +1,6 @@
-import type { ActionDefinition, Context, FeedItemSignals, FeedSource } from "@aris/core"
+import type { ActionDefinition, ContextEntry, FeedItemSignals, FeedSource } from "@aris/core"
 
-import { TimeRelevance, UnknownActionError, contextValue } from "@aris/core"
+import { Context, TimeRelevance, UnknownActionError } from "@aris/core"
 import { LocationKey } from "@aris/source-location"
 import { type } from "arktype"
 
@@ -15,6 +15,7 @@ import type {
 } from "./types.ts"
 
 import { TflApi, lineId } from "./tfl-api.ts"
+import { TflFeedItemType } from "./types.ts"
 
 const setLinesInput = lineId.array()
 
@@ -111,7 +112,7 @@ export class TflSource implements FeedSource<TflAlertFeedItem> {
 		}
 	}
 
-	async fetchContext(): Promise<null> {
+	async fetchContext(): Promise<readonly ContextEntry[] | null> {
 		return null
 	}
 
@@ -128,7 +129,7 @@ export class TflSource implements FeedSource<TflAlertFeedItem> {
 			this.client.fetchStations(),
 		])
 
-		const location = contextValue(context, LocationKey)
+		const location = context.get(LocationKey)
 
 		const items: TflAlertFeedItem[] = statuses.map((status) => {
 			const closestStationDistance = location
@@ -150,7 +151,7 @@ export class TflSource implements FeedSource<TflAlertFeedItem> {
 
 			return {
 				id: `tfl-alert-${status.lineId}-${status.severity}`,
-				type: "tfl-alert",
+				type: TflFeedItemType.Alert,
 				timestamp: context.time,
 				data,
 				signals,

packages/aris-source-tfl/src/types.ts

@@ -20,7 +20,13 @@ export interface TflAlertData extends Record<string, unknown> {
 	closestStationDistance: number | null
 }
 
-export type TflAlertFeedItem = FeedItem<"tfl-alert", TflAlertData>
+export const TflFeedItemType = {
+	Alert: "tfl-alert",
+} as const
+
+export type TflFeedItemType = (typeof TflFeedItemType)[keyof typeof TflFeedItemType]
+
+export type TflAlertFeedItem = FeedItem<typeof TflFeedItemType.Alert, TflAlertData>
 
 export interface TflSourceOptions {
 	apiKey?: string

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

@@ -3,10 +3,10 @@ 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",
+	Current: "weather-current",
+	Hourly: "weather-hourly",
+	Daily: "weather-daily",
+	Alert: "weather-alert",
 } as const
 
 export type WeatherFeedItemType = (typeof WeatherFeedItemType)[keyof typeof WeatherFeedItemType]
@@ -28,7 +28,7 @@ export type CurrentWeatherData = {
 }
 
 export interface CurrentWeatherFeedItem extends FeedItem<
-	typeof WeatherFeedItemType.current,
+	typeof WeatherFeedItemType.Current,
 	CurrentWeatherData
 > {}
 
@@ -49,7 +49,7 @@ export type HourlyWeatherData = {
 }
 
 export interface HourlyWeatherFeedItem extends FeedItem<
-	typeof WeatherFeedItemType.hourly,
+	typeof WeatherFeedItemType.Hourly,
 	HourlyWeatherData
 > {}
 
@@ -68,7 +68,7 @@ export type DailyWeatherData = {
 }
 
 export interface DailyWeatherFeedItem extends FeedItem<
-	typeof WeatherFeedItemType.daily,
+	typeof WeatherFeedItemType.Daily,
 	DailyWeatherData
 > {}
 
@@ -86,7 +86,7 @@ export type WeatherAlertData = {
 }
 
 export interface WeatherAlertFeedItem extends FeedItem<
-	typeof WeatherFeedItemType.alert,
+	typeof WeatherFeedItemType.Alert,
 	WeatherAlertData
 > {}
 

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

@@ -1,14 +1,8 @@
 export { WeatherKey, type Weather } from "./weather-context"
-export {
-	WeatherSource,
-	Units,
-	type Units as UnitsType,
-	type WeatherSourceOptions,
-} from "./weather-source"
+export { WeatherSource, Units, type WeatherSourceOptions } from "./weather-source"
 
 export {
 	WeatherFeedItemType,
-	type WeatherFeedItemType as WeatherFeedItemTypeType,
 	type WeatherFeedItem,
 	type CurrentWeatherFeedItem,
 	type CurrentWeatherData,
@@ -27,11 +21,6 @@ export {
 	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,

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

@@ -24,4 +24,4 @@ export interface Weather {
 	daylight: boolean
 }
 
-export const WeatherKey: ContextKey<Weather> = contextKey("weather")
+export const WeatherKey: ContextKey<Weather> = contextKey("aris.weather", "weather")

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

@@ -1,4 +1,6 @@
-import { contextValue, type Context } from "@aris/core"
+import type { FeedSource } from "@aris/core"
+
+import { Context } from "@aris/core"
 import { LocationKey } from "@aris/source-location"
 import { describe, expect, test } from "bun:test"
 
@@ -6,7 +8,7 @@ import type { WeatherKitClient, WeatherKitResponse } from "./weatherkit"
 
 import fixture from "../fixtures/san-francisco.json"
 import { WeatherFeedItemType } from "./feed-items"
-import { WeatherKey } from "./weather-context"
+import { WeatherKey, type Weather } from "./weather-context"
 import { WeatherSource, Units } from "./weather-source"
 
 const mockCredentials = {
@@ -23,9 +25,9 @@ function createMockClient(response: WeatherKitResponse): WeatherKitClient {
 }
 
 function createMockContext(location?: { lat: number; lng: number }): Context {
-	const ctx: Context = { time: new Date("2026-01-17T00:00:00Z") }
+	const ctx = new Context(new Date("2026-01-17T00:00:00Z"))
 	if (location) {
-		ctx[LocationKey] = { ...location, accuracy: 10, timestamp: new Date() }
+		ctx.set([[LocationKey, { ...location, accuracy: 10, timestamp: new Date() }]])
 	}
 	return ctx
 }
@@ -63,18 +65,19 @@ describe("WeatherSource", () => {
 			const source = new WeatherSource({ client: mockClient })
 			const context = createMockContext({ lat: 37.7749, lng: -122.4194 })
 
-			const result = await source.fetchContext(context)
-			expect(result).not.toBeNull()
-			const weather = contextValue(result! as Context, WeatherKey)
+			const entries = await source.fetchContext(context)
+			expect(entries).not.toBeNull()
+			expect(entries).toHaveLength(1)
 
-			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")
+			const [key, weather] = entries![0]! as [typeof WeatherKey, Weather]
+			expect(key).toEqual(WeatherKey)
+			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 () => {
@@ -84,12 +87,12 @@ describe("WeatherSource", () => {
 			})
 			const context = createMockContext({ lat: 37.7749, lng: -122.4194 })
 
-			const result = await source.fetchContext(context)
-			expect(result).not.toBeNull()
-			const weather = contextValue(result! as Context, WeatherKey)
+			const entries = await source.fetchContext(context)
+			expect(entries).not.toBeNull()
 
+			const [, weather] = entries![0]! as [typeof WeatherKey, Weather]
 			// Fixture has temperature around 10°C, imperial should be around 50°F
-			expect(weather!.temperature).toBeGreaterThan(40)
+			expect(weather.temperature).toBeGreaterThan(40)
 		})
 	})
 
@@ -110,9 +113,9 @@ describe("WeatherSource", () => {
 			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)
+			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 () => {
@@ -125,8 +128,8 @@ describe("WeatherSource", () => {
 
 			const items = await source.fetchItems(context)
 
-			const hourlyItems = items.filter((i) => i.type === WeatherFeedItemType.hourly)
-			const dailyItems = items.filter((i) => i.type === WeatherFeedItemType.daily)
+			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)
@@ -158,7 +161,7 @@ describe("WeatherSource", () => {
 				expect(item.signals!.timeRelevance).toBeDefined()
 			}
 
-			const currentItem = items.find((i) => i.type === WeatherFeedItemType.current)
+			const currentItem = items.find((i) => i.type === WeatherFeedItemType.Current)
 			expect(currentItem).toBeDefined()
 			expect(currentItem!.signals!.urgency).toBeGreaterThanOrEqual(0.5)
 		})
@@ -177,12 +180,12 @@ describe("WeatherSource", () => {
 
 	describe("no reactive methods", () => {
 		test("does not implement onContextUpdate", () => {
-			const source = new WeatherSource({ credentials: mockCredentials })
+			const source: FeedSource = new WeatherSource({ credentials: mockCredentials })
 			expect(source.onContextUpdate).toBeUndefined()
 		})
 
 		test("does not implement onItemsUpdate", () => {
-			const source = new WeatherSource({ credentials: mockCredentials })
+			const source: FeedSource = new WeatherSource({ credentials: mockCredentials })
 			expect(source.onItemsUpdate).toBeUndefined()
 		})
 	})

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

@@ -1,6 +1,6 @@
-import type { ActionDefinition, Context, FeedItemSignals, FeedSource } from "@aris/core"
+import type { ActionDefinition, ContextEntry, FeedItemSignals, FeedSource } from "@aris/core"
 
-import { TimeRelevance, UnknownActionError, contextValue } from "@aris/core"
+import { Context, TimeRelevance, UnknownActionError } from "@aris/core"
 import { LocationKey } from "@aris/source-location"
 
 import { WeatherFeedItemType, type WeatherFeedItem } from "./feed-items"
@@ -86,7 +86,7 @@ const MODERATE_CONDITIONS = new Set<ConditionCode>([
  * })
  *
  * // Access weather context in downstream sources
- * const weather = contextValue(context, WeatherKey)
+ * const weather = context.get(WeatherKey)
  * if (weather?.condition === "Rain") {
  *   // suggest umbrella
  * }
@@ -119,8 +119,8 @@ export class WeatherSource implements FeedSource<WeatherFeedItem> {
 		throw new UnknownActionError(actionId)
 	}
 
-	async fetchContext(context: Context): Promise<Partial<Context> | null> {
-		const location = contextValue(context, LocationKey)
+	async fetchContext(context: Context): Promise<readonly ContextEntry[] | null> {
+		const location = context.get(LocationKey)
 		if (!location) {
 			return null
 		}
@@ -147,11 +147,11 @@ export class WeatherSource implements FeedSource<WeatherFeedItem> {
 			daylight: response.currentWeather.daylight,
 		}
 
-		return { [WeatherKey]: weather }
+		return [[WeatherKey, weather]]
 	}
 
 	async fetchItems(context: Context): Promise<WeatherFeedItem[]> {
-		const location = contextValue(context, LocationKey)
+		const location = context.get(LocationKey)
 		if (!location) {
 			return []
 		}
@@ -291,7 +291,7 @@ function createCurrentWeatherFeedItem(
 
 	return {
 		id: `weather-current-${timestamp.getTime()}`,
-		type: WeatherFeedItemType.current,
+		type: WeatherFeedItemType.Current,
 		timestamp,
 		data: {
 			conditionCode: current.conditionCode,
@@ -325,7 +325,7 @@ function createHourlyWeatherFeedItem(
 
 	return {
 		id: `weather-hourly-${timestamp.getTime()}-${index}`,
-		type: WeatherFeedItemType.hourly,
+		type: WeatherFeedItemType.Hourly,
 		timestamp,
 		data: {
 			forecastTime: new Date(hourly.forecastStart),
@@ -359,7 +359,7 @@ function createDailyWeatherFeedItem(
 
 	return {
 		id: `weather-daily-${timestamp.getTime()}-${index}`,
-		type: WeatherFeedItemType.daily,
+		type: WeatherFeedItemType.Daily,
 		timestamp,
 		data: {
 			forecastDate: new Date(daily.forecastStart),
@@ -386,7 +386,7 @@ function createWeatherAlertFeedItem(alert: WeatherAlert, timestamp: Date): Weath
 
 	return {
 		id: `weather-alert-${alert.id}`,
-		type: WeatherFeedItemType.alert,
+		type: WeatherFeedItemType.Alert,
 		timestamp,
 		data: {
 			alertId: alert.id,