B2B-88: add starter kit structure and elements

packages/billing/stripe/src/services/create-stripe-billing-portal-session.ts

@@ -0,0 +1,18 @@
+import type { Stripe } from 'stripe';
+import { z } from 'zod';
+
+import type { CreateBillingPortalSessionSchema } from '@kit/billing/schema';
+
+/**
+ * @name createStripeBillingPortalSession
+ * @description Create a Stripe billing portal session for a user
+ */
+export async function createStripeBillingPortalSession(
+  stripe: Stripe,
+  params: z.infer<typeof CreateBillingPortalSessionSchema>,
+) {
+  return stripe.billingPortal.sessions.create({
+    customer: params.customerId,
+    return_url: params.returnUrl,
+  });
+}