feat: add exa web search source (#124)

packages/freya-source-web-search/package.json

@@ -0,0 +1,14 @@
+{
+	"name": "@freya/source-web-search",
+	"version": "0.0.0",
+	"type": "module",
+	"main": "src/index.ts",
+	"types": "src/index.ts",
+	"scripts": {
+		"test": "bun test ."
+	},
+	"dependencies": {
+		"@freya/core": "workspace:*",
+		"arktype": "^2.1.0"
+	}
+}

packages/freya-source-web-search/src/exa-client.test.ts

@@ -0,0 +1,97 @@
+import { describe, expect, test } from "bun:test"
+
+import { ExaSearchClient } from "./exa-client.ts"
+
+describe("ExaSearchClient", () => {
+	test("maps request and response", async () => {
+		const originalFetch = globalThis.fetch
+		let requestUrl = ""
+		let requestHeaders: Headers
+		let requestBody: unknown
+
+		globalThis.fetch = (async (
+			input: Parameters<typeof fetch>[0],
+			init?: Parameters<typeof fetch>[1],
+		) => {
+			requestUrl = String(input)
+			requestHeaders = new Headers(init?.headers)
+			requestBody = JSON.parse(String(init?.body))
+
+			return new Response(
+				JSON.stringify({
+					requestId: "exa-request-1",
+					results: [
+						{
+							id: "result-1",
+							url: "https://example.com",
+							title: "Example",
+							publishedDate: "2026-01-01T00:00:00.000Z",
+							author: "Author",
+							image: "https://example.com/image.png",
+							favicon: "https://example.com/favicon.ico",
+							highlights: ["A useful passage"],
+							highlightScores: [0.7],
+							summary: "Summary",
+						},
+					],
+				}),
+				{ status: 200 },
+			)
+		}) as unknown as typeof fetch
+
+		try {
+			const client = new ExaSearchClient("api-key", "https://api.example.test")
+			const result = await client.search({
+				query: "test query",
+				numResults: 3,
+				includeDomains: ["example.com"],
+				highlights: false,
+			})
+
+			expect(requestUrl).toBe("https://api.example.test/search")
+			expect(requestHeaders!.get("x-api-key")).toBe("api-key")
+			expect(requestBody).toEqual({
+				query: "test query",
+				numResults: 3,
+				includeDomains: ["example.com"],
+				contents: { highlights: false },
+			})
+			expect(result).toEqual({
+				query: "test query",
+				requestId: "exa-request-1",
+				results: [
+					{
+						id: "result-1",
+						url: "https://example.com",
+						title: "Example",
+						publishedDate: "2026-01-01T00:00:00.000Z",
+						author: "Author",
+						image: "https://example.com/image.png",
+						favicon: "https://example.com/favicon.ico",
+						text: null,
+						highlights: ["A useful passage"],
+						highlightScores: [0.7],
+						summary: "Summary",
+					},
+				],
+			})
+		} finally {
+			globalThis.fetch = originalFetch
+		}
+	})
+
+	test("throws on non-ok response", async () => {
+		const originalFetch = globalThis.fetch
+		globalThis.fetch = (async () =>
+			new Response("nope", { status: 401, statusText: "Unauthorized" })) as unknown as typeof fetch
+
+		try {
+			const client = new ExaSearchClient("bad-key")
+			await expect(client.search({ query: "test" })).rejects.toThrow(
+				"Exa API error: 401 Unauthorized",
+			)
+		} finally {
+			globalThis.fetch = originalFetch
+		}
+	})
+})

packages/freya-source-web-search/src/exa-client.ts

@@ -0,0 +1,124 @@
+import { type } from "arktype"
+
+import type {
+	WebSearchClient,
+	WebSearchRequest,
+	WebSearchResponse,
+	WebSearchResult,
+} from "./types.ts"
+
+const EXA_API_BASE = "https://api.exa.ai"
+const DEFAULT_NUM_RESULTS = 10
+
+const ExaSearchResult = type({
+	id: "string",
+	url: "string",
+	"title?": "string | null",
+	"publishedDate?": "string | null",
+	"author?": "string | null",
+	"image?": "string | null",
+	"favicon?": "string | null",
+	"text?": "string | null",
+	"highlights?": "string[]",
+	"highlightScores?": "number[]",
+	"summary?": "string | null",
+})
+
+const ExaSearchResponse = type({
+	results: ExaSearchResult.array(),
+	"requestId?": "string",
+})
+
+interface ExaSearchBody {
+	query: string
+	numResults?: number
+	includeDomains?: string[]
+	excludeDomains?: string[]
+	startCrawlDate?: string
+	endCrawlDate?: string
+	startPublishedDate?: string
+	endPublishedDate?: string
+	type?: WebSearchRequest["type"]
+	category?: string
+	userLocation?: string
+	moderation?: boolean
+	contents: {
+		highlights: boolean
+	}
+}
+
+export class ExaSearchClient implements WebSearchClient {
+	private readonly apiKey: string
+	private readonly baseUrl: string
+
+	constructor(apiKey: string, baseUrl = EXA_API_BASE) {
+		this.apiKey = apiKey
+		this.baseUrl = baseUrl
+	}
+
+	async search(request: WebSearchRequest): Promise<WebSearchResponse> {
+		const response = await fetch(new URL("/search", this.baseUrl), {
+			method: "POST",
+			headers: {
+				"Content-Type": "application/json",
+				"x-api-key": this.apiKey,
+			},
+			body: JSON.stringify(toExaSearchBody(request)),
+		})
+
+		if (!response.ok) {
+			throw new Error(`Exa API error: ${response.status} ${response.statusText}`)
+		}
+
+		const data = await response.json()
+		const parsed = ExaSearchResponse(data)
+		if (parsed instanceof type.errors) {
+			throw new Error(`Invalid Exa API response: ${parsed.summary}`)
+		}
+
+		return {
+			query: request.query,
+			requestId: parsed.requestId ?? null,
+			results: parsed.results.map(toWebSearchResult),
+		}
+	}
+}
+
+function toExaSearchBody(request: WebSearchRequest): ExaSearchBody {
+	const body: ExaSearchBody = {
+		query: request.query,
+		numResults: request.numResults ?? DEFAULT_NUM_RESULTS,
+		contents: {
+			highlights: request.highlights ?? true,
+		},
+	}
+
+	if (request.includeDomains) body.includeDomains = request.includeDomains
+	if (request.excludeDomains) body.excludeDomains = request.excludeDomains
+	if (request.startCrawlDate) body.startCrawlDate = request.startCrawlDate
+	if (request.endCrawlDate) body.endCrawlDate = request.endCrawlDate
+	if (request.startPublishedDate) body.startPublishedDate = request.startPublishedDate
+	if (request.endPublishedDate) body.endPublishedDate = request.endPublishedDate
+	if (request.type) body.type = request.type
+	if (request.category) body.category = request.category
+	if (request.userLocation) body.userLocation = request.userLocation
+	if (request.moderation !== undefined) body.moderation = request.moderation
+
+	return body
+}
+
+function toWebSearchResult(result: typeof ExaSearchResult.infer): WebSearchResult {
+	return {
+		id: result.id,
+		url: result.url,
+		title: result.title ?? null,
+		publishedDate: result.publishedDate ?? null,
+		author: result.author ?? null,
+		image: result.image ?? null,
+		favicon: result.favicon ?? null,
+		text: result.text ?? null,
+		highlights: result.highlights ?? [],
+		highlightScores: result.highlightScores ?? [],
+		summary: result.summary ?? null,
+	}
+}

packages/freya-source-web-search/src/index.ts

@@ -0,0 +1,11 @@
+export { ExaSearchClient } from "./exa-client.ts"
+export { WebSearchSource } from "./web-search-source.ts"
+export {
+	WebSearchAction,
+	WebSearchType,
+	type WebSearchClient,
+	type WebSearchRequest,
+	type WebSearchResponse,
+	type WebSearchResult,
+	type WebSearchSourceOptions,
+} from "./types.ts"

packages/freya-source-web-search/src/types.ts

@@ -0,0 +1,61 @@
+export const WebSearchAction = {
+	Search: "search",
+} as const
+
+export type WebSearchAction = (typeof WebSearchAction)[keyof typeof WebSearchAction]
+
+export const WebSearchType = {
+	Instant: "instant",
+	Fast: "fast",
+	Auto: "auto",
+	DeepLite: "deep-lite",
+	Deep: "deep",
+	DeepReasoning: "deep-reasoning",
+} as const
+
+export type WebSearchType = (typeof WebSearchType)[keyof typeof WebSearchType]
+
+export interface WebSearchRequest {
+	query: string
+	numResults?: number
+	includeDomains?: string[]
+	excludeDomains?: string[]
+	startCrawlDate?: string
+	endCrawlDate?: string
+	startPublishedDate?: string
+	endPublishedDate?: string
+	type?: WebSearchType
+	category?: string
+	userLocation?: string
+	moderation?: boolean
+	highlights?: boolean
+}
+
+export interface WebSearchResult extends Record<string, unknown> {
+	id: string
+	url: string
+	title: string | null
+	publishedDate: string | null
+	author: string | null
+	image: string | null
+	favicon: string | null
+	text: string | null
+	highlights: string[]
+	highlightScores: number[]
+	summary: string | null
+}
+
+export interface WebSearchResponse extends Record<string, unknown> {
+	query: string
+	requestId: string | null
+	results: WebSearchResult[]
+}
+
+export interface WebSearchClient {
+	search(request: WebSearchRequest): Promise<WebSearchResponse>
+}
+
+export interface WebSearchSourceOptions {
+	apiKey?: string
+	client?: WebSearchClient
+}

packages/freya-source-web-search/src/web-search-source.test.ts

@@ -0,0 +1,123 @@
+import { Context } from "@freya/core"
+import { describe, expect, test } from "bun:test"
+
+import type { WebSearchClient, WebSearchRequest, WebSearchResponse } from "./types.ts"
+
+import { WebSearchAction } from "./types.ts"
+import { WebSearchSource } from "./web-search-source.ts"
+
+class RecordingSearchClient implements WebSearchClient {
+	requests: WebSearchRequest[] = []
+
+	async search(request: WebSearchRequest): Promise<WebSearchResponse> {
+		this.requests.push(request)
+		return {
+			query: request.query,
+			requestId: "request-1",
+			results: [
+				{
+					id: "https://example.com/a",
+					url: "https://example.com/a",
+					title: "Example result",
+					publishedDate: "2026-01-01T00:00:00.000Z",
+					author: "Example Author",
+					image: null,
+					favicon: "https://example.com/favicon.ico",
+					text: null,
+					highlights: ["Relevant excerpt"],
+					highlightScores: [0.8],
+					summary: null,
+				},
+			],
+		}
+	}
+}
+
+describe("WebSearchSource", () => {
+	test("has correct id", () => {
+		const source = new WebSearchSource({ client: new RecordingSearchClient() })
+
+		expect(source.id).toBe("freya.web-search")
+	})
+
+	test("does not provide context or feed items", async () => {
+		const source = new WebSearchSource({ client: new RecordingSearchClient() })
+
+		expect("fetchItems" in source).toBe(false)
+		expect(await source.fetchContext(new Context())).toBeNull()
+	})
+
+	test("lists search action", async () => {
+		const source = new WebSearchSource({ client: new RecordingSearchClient() })
+		const actions = await source.listActions()
+
+		expect(actions[WebSearchAction.Search]).toBeDefined()
+		expect(actions[WebSearchAction.Search]!.id).toBe(WebSearchAction.Search)
+		expect(actions[WebSearchAction.Search]!.input).toBeDefined()
+	})
+
+	test("executes search action with normalized params", async () => {
+		const client = new RecordingSearchClient()
+		const source = new WebSearchSource({ client })
+
+		const result = await source.executeAction(WebSearchAction.Search, {
+			query: "  latest personal assistant research  ",
+			includeDomains: ["exa.ai"],
+			type: "fast",
+			userLocation: "gb",
+			moderation: true,
+		})
+
+		expect(result.requestId).toBe("request-1")
+		expect(result.results).toHaveLength(1)
+		expect(client.requests).toEqual([
+			{
+				query: "latest personal assistant research",
+				numResults: 10,
+				includeDomains: ["exa.ai"],
+				type: "fast",
+				userLocation: "GB",
+				moderation: true,
+			},
+		])
+	})
+
+	test("allows per-call numResults override", async () => {
+		const client = new RecordingSearchClient()
+		const source = new WebSearchSource({ client })
+
+		await source.executeAction(WebSearchAction.Search, {
+			query: "freya",
+			numResults: 2,
+		})
+
+		expect(client.requests[0]!.numResults).toBe(2)
+	})
+
+	test("throws for invalid action", async () => {
+		const source = new WebSearchSource({ client: new RecordingSearchClient() })
+
+		await expect(source.executeAction("missing", {})).rejects.toThrow("Unknown action")
+	})
+
+	test("throws for invalid search params", async () => {
+		const source = new WebSearchSource({ client: new RecordingSearchClient() })
+
+		await expect(
+			source.executeAction(WebSearchAction.Search, {
+				query: "",
+			}),
+		).rejects.toThrow("query must not be empty")
+
+		await expect(
+			source.executeAction(WebSearchAction.Search, {
+				query: "x",
+				numResults: 101,
+			}),
+		).rejects.toThrow("numResults must be an integer")
+	})
+
+	test("throws if neither client nor apiKey is provided", () => {
+		expect(() => new WebSearchSource({})).toThrow("Either client or apiKey must be provided")
+	})
+})

packages/freya-source-web-search/src/web-search-source.ts

@@ -0,0 +1,121 @@
+import type { ActionDefinition, Context, ContextEntry, FeedSource } from "@freya/core"
+
+import { UnknownActionError } from "@freya/core"
+import { type } from "arktype"
+
+import type {
+	WebSearchClient,
+	WebSearchRequest,
+	WebSearchResponse,
+	WebSearchSourceOptions,
+} from "./types.ts"
+
+import { ExaSearchClient } from "./exa-client.ts"
+import { WebSearchAction, WebSearchType } from "./types.ts"
+
+const DEFAULT_NUM_RESULTS = 10
+const MIN_NUM_RESULTS = 1
+const MAX_NUM_RESULTS = 100
+
+const SearchInput = type({
+	"+": "reject",
+	query: "string",
+	"numResults?": "number",
+	"includeDomains?": "string[]",
+	"excludeDomains?": "string[]",
+	"startCrawlDate?": "string.date.iso",
+	"endCrawlDate?": "string.date.iso",
+	"startPublishedDate?": "string.date.iso",
+	"endPublishedDate?": "string.date.iso",
+	"type?": "'instant' | 'fast' | 'auto' | 'deep-lite' | 'deep' | 'deep-reasoning'",
+	"category?": "string",
+	"userLocation?": "string",
+	"moderation?": "boolean",
+	"highlights?": "boolean",
+})
+
+/**
+ * Action-only FeedSource for web search through Exa.
+ *
+ * It intentionally does not produce feed items. Consumers call the `search`
+ * action and receive structured web results.
+ */
+export class WebSearchSource implements FeedSource {
+	readonly id = "freya.web-search"
+
+	private readonly client: WebSearchClient
+
+	constructor(options: WebSearchSourceOptions) {
+		if (!options.client && !options.apiKey) {
+			throw new Error("Either client or apiKey must be provided")
+		}
+		this.client = options.client ?? new ExaSearchClient(options.apiKey!)
+	}
+
+	async listActions(): Promise<Record<string, ActionDefinition>> {
+		return {
+			[WebSearchAction.Search]: {
+				id: WebSearchAction.Search,
+				description: "Search the web and return structured results",
+				input: SearchInput,
+			},
+		}
+	}
+
+	async executeAction(actionId: string, params: unknown): Promise<WebSearchResponse> {
+		switch (actionId) {
+			case WebSearchAction.Search:
+				return this.client.search(this.parseSearchInput(params))
+			default:
+				throw new UnknownActionError(actionId)
+		}
+	}
+
+	async fetchContext(_context: Context): Promise<readonly ContextEntry[] | null> {
+		return null
+	}
+
+	private parseSearchInput(params: unknown): WebSearchRequest {
+		const parsed = SearchInput(params)
+		if (parsed instanceof type.errors) {
+			throw new Error(parsed.summary)
+		}
+
+		const query = parsed.query.trim()
+		if (!query) {
+			throw new Error("query must not be empty")
+		}
+
+		const numResults = parsed.numResults ?? DEFAULT_NUM_RESULTS
+		if (
+			!Number.isInteger(numResults) ||
+			numResults < MIN_NUM_RESULTS ||
+			numResults > MAX_NUM_RESULTS
+		) {
+			throw new Error(`numResults must be an integer from ${MIN_NUM_RESULTS} to ${MAX_NUM_RESULTS}`)
+		}
+
+		if (parsed.userLocation && !/^[A-Za-z]{2}$/.test(parsed.userLocation)) {
+			throw new Error("userLocation must be a two-letter ISO country code")
+		}
+
+		const request: WebSearchRequest = {
+			query,
+			numResults,
+		}
+
+		if (parsed.includeDomains) request.includeDomains = parsed.includeDomains
+		if (parsed.excludeDomains) request.excludeDomains = parsed.excludeDomains
+		if (parsed.startCrawlDate) request.startCrawlDate = parsed.startCrawlDate
+		if (parsed.endCrawlDate) request.endCrawlDate = parsed.endCrawlDate
+		if (parsed.startPublishedDate) request.startPublishedDate = parsed.startPublishedDate
+		if (parsed.endPublishedDate) request.endPublishedDate = parsed.endPublishedDate
+		if (parsed.type) request.type = parsed.type as WebSearchType
+		if (parsed.category) request.category = parsed.category
+		if (parsed.userLocation) request.userLocation = parsed.userLocation.toUpperCase()
+		if (parsed.moderation !== undefined) request.moderation = parsed.moderation
+		if (parsed.highlights !== undefined) request.highlights = parsed.highlights
+
+		return request
+	}
+}