diff --git a/packages/pi-ai/src/utils/event-stream.ts b/packages/pi-ai/src/utils/event-stream.ts
index 74947477e..7eb0a0104 100644
--- a/packages/pi-ai/src/utils/event-stream.ts
+++ b/packages/pi-ai/src/utils/event-stream.ts
@@ -80,3 +80,8 @@ export class AssistantMessageEventStream extends EventStream<AssistantMessageEve
 		);
 	}
 }
+
+/** Factory function for AssistantMessageEventStream (for use by package consumers). */
+export function createAssistantMessageEventStream(): AssistantMessageEventStream {
+	return new AssistantMessageEventStream();
+}
diff --git a/src/tests/pi-ai-event-stream-factory.test.ts b/src/tests/pi-ai-event-stream-factory.test.ts
new file mode 100644
index 000000000..e43b1df64
--- /dev/null
+++ b/src/tests/pi-ai-event-stream-factory.test.ts
@@ -0,0 +1,14 @@
+import { describe, it } from "node:test";
+import assert from "node:assert/strict";
+import {
+	AssistantMessageEventStream,
+	createAssistantMessageEventStream,
+} from "@gsd/pi-ai";
+
+describe("@gsd/pi-ai event stream exports", () => {
+	it("exports createAssistantMessageEventStream for package consumers", () => {
+		assert.equal(typeof createAssistantMessageEventStream, "function");
+		const stream = createAssistantMessageEventStream();
+		assert.ok(stream instanceof AssistantMessageEventStream);
+	});
+});