Initial import of zappier-edge from zapier monorepo

src/billing/reload.ts

@@ -0,0 +1,31 @@
+import Stripe from 'stripe';
+import { PaymentClient } from '../portal';
+
+/**
+ * Stripe-backed reloads: creates a PaymentIntent and returns its client
+ * secret. The balance is credited only after the payment confirms (webhook
+ * step); until then creditedCents is 0 and the intent is pending.
+ */
+export function stripePaymentClient(secretKey: string): PaymentClient {
+  const stripe = new Stripe(secretKey);
+  return {
+    reload: async (customer, amountCents) => {
+      const intent = await stripe.paymentIntents.create({
+        amount: amountCents,
+        currency: 'usd',
+        automatic_payment_methods: { enabled: true },
+        metadata: { customerId: customer.id },
+      });
+      return {
+        mode: 'stripe',
+        creditedCents: 0,
+        clientSecret: intent.client_secret ?? undefined,
+      };
+    },
+  };
+}
+
+/** True when the key looks usable (not empty / not the setup placeholder). */
+export function hasRealStripeKey(key: string | undefined): key is string {
+  return typeof key === 'string' && key.startsWith('sk_');
+}