diff --git a/examples/demo-app/src/services/paymentService.ts b/examples/demo-app/src/services/paymentService.ts
new file mode 100644
index 0000000..f5b358e
--- /dev/null
+++ b/examples/demo-app/src/services/paymentService.ts
@@ -0,0 +1,8 @@
+import { getUser } from '../lib/auth';
+import { getOrderForUser } from './orderService';
+
+export async function processPayment(orderId: string, userId: string) {
+  const user = await getUser(userId);
+  const order = await getOrderForUser(orderId, userId);
+  return { success: true, user, order };
+}