feat: add exa web search source (#124)

apps/freya-backend/src/web-search/provider.ts

@@ -0,0 +1,30 @@
+import { WebSearchSource, type WebSearchClient } from "@freya/source-web-search"
+
+import type { FeedSourceProvider } from "../session/feed-source-provider.ts"
+
+export type WebSearchSourceProviderOptions =
+	| { apiKey: string | undefined; client?: never }
+	| { apiKey?: never; client: WebSearchClient }
+
+export class WebSearchSourceProvider implements FeedSourceProvider {
+	readonly sourceId = "freya.web-search"
+
+	private readonly apiKey: string | undefined
+	private readonly client: WebSearchClient | undefined
+
+	constructor(options: WebSearchSourceProviderOptions) {
+		this.apiKey = "apiKey" in options ? options.apiKey : undefined
+		this.client = "client" in options ? options.client : undefined
+	}
+
+	async feedSourceForUser(
+		_userId: string,
+		_config: unknown,
+		_credentials: unknown,
+	): Promise<WebSearchSource> {
+		return new WebSearchSource({
+			apiKey: this.apiKey,
+			client: this.client,
+		})
+	}
+}