secure-payment-webhook-access

Securely handling Stripe and Xendit webhooks requires verifying event signatures before body parsing, enforcing idempotency to prevent duplicate grants, and gating access only when Purchase.status is COMPLETED.

Payment succeeding without access usually indicates missing access checks on download routes or non-atomic state updates. You must ensure transitions occur only after a verified webhook event updates the Purchase.status to COMPLETED.

Preventing duplicate access grants on repeated webhook deliveries requires implementing idempotency checks within your webhook handler to ensure the same event does not trigger multiple transactional state updates.

Ensuring consistent payment state changes requires using atomic transactions, such as prisma.$transaction, to update Purchase records securely after a webhook's signature verification succeeds.

Yes, this webhook security approach works for both by enforcing gate logic that validates either a COMPLETED Purchase.status for one-time payments or an active subscription state for recurring access.

Signature verification for webhook handlers is needed before any database access or body parsing to prevent unauthorized access via client-side redirects or unreliable client signals.