Payment and booking coupling

Without bidirectional references between the booking record and the payment provider transaction, any webhook processing failure becomes an irrecoverable data loss: you cannot look up the booking from the payment event, and you cannot look up the payment from the booking record. CWE-706 (use of incorrectly-resolved name or reference) and CWE-841 both apply. This is the root cause of "customer was charged but has no booking" incidents that require manual database forensics: the payment provider has the charge, the application has the booking, but there is no programmatic link between them. Every refund, rebooking, and dispute resolution becomes a manual operation.

Add a paymentIntentId column to the Booking model and pass the booking ID in the payment provider's metadata. Add this in prisma/schema.prisma and your checkout handler.

// schema.prisma
model Booking {
  id              String  @id @default(cuid())
  paymentIntentId String? // Stripe PaymentIntent ID
}

// In checkout handler
const intent = await stripe.paymentIntents.create({
  amount,
  metadata: { bookingId: booking.id }, // payment -> booking
});
await db.booking.update({
  where: { id: booking.id },
  data: { paymentIntentId: intent.id }, // booking -> payment
});

• ID: booking-flow-lifecycle.payment.payment-booking-coupling

• Label: Payment and booking coupling

• Severity: critical

• What to look for: Count all links between booking and payment records. The Booking model must store the payment provider's transaction/intent ID (e.g., paymentIntentId for Stripe, orderId for PayPal). The Payment/Transaction record must store the Booking ID (typically in metadata for Stripe, or a separate payments table with bookingId foreign key). Verify bidirectional links exist: booking-to-payment AND payment-to-booking. Enumerate: "X of 2 bidirectional links present: [booking->payment: field, payment->booking: field]."

• Pass criteria: Both directions of the link must exist — at least 2 of 2 bidirectional references required. (1) Booking model has a field storing the payment provider's ID (e.g., paymentIntentId, stripeSessionId, paypalOrderId). (2) Payment provider metadata or a local payments table stores the booking ID. Report: "2 of 2 bidirectional links present: booking.paymentIntentId -> Stripe, Stripe metadata.bookingId -> booking." Report even on pass: "Bidirectional link: booking.[field] <-> [payment provider metadata/table].[field] in [schema file]."

• Fail criteria: No link between the two in either or both directions. Payments and bookings are orphaned and cannot be correlated. Also fails if only 1 direction exists (booking stores payment ID but payment does not store booking ID, or vice versa).

• Skip (N/A) when: No payment integration (no Stripe, PayPal, Square, or other payment SDK in package.json dependencies).

• Detail on fail: "Booking model lacks a paymentIntentId or paymentId field. If a webhook fails, there is no way to recover which payment corresponds to which booking."

• Cross-reference: The confirmation-record check in Booking Creation verifies the booking ID is passed to the payment provider at creation time.

• Cross-reference: The refund-logic check in this category needs this link to identify which payment to refund.

• Cross-reference: The retry-mechanism check in this category needs consistent IDs for idempotency.

• Remediation: Add bidirectional references in your schema (e.g., prisma/schema.prisma) and payment creation code.

  model Booking {
    id String @id
    paymentIntentId String? // Link to Stripe PaymentIntent
    // ... other fields
  }
  
  // On payment intent creation, include booking ID in metadata
  const paymentIntent = await stripe.paymentIntents.create({
    amount,
    metadata: { bookingId: booking.id }
  });
  
  // In webhook, extract booking ID from metadata
  const bookingId = event.data.object.metadata.bookingId;