What problem does it solve? Payment code changes can introduce duplicate ticket issuance, replayed webhooks, forged payment status, or leaked secrets. This Skill provides a focused review checklist for Stripe-related pull requests so reviewers catch signature, idempotency, replay, authority, and secret-boundary defects before merge. ## Core Features & Use Cases - Webhook Verification Review: Confirms signatures are verified from the raw request body before events are trusted. - Idempotency and Replay Checks: Ensures duplicate webhook delivery cannot duplicate tickets, ledger rows, inventory changes, or payouts. - Server-Side Authority Enforcement: Flags any reliance on client-controlled payment status, amounts, prices, or ownership, and checks secret keys stay server-only. - Use Case: A pull request modifies the ticket checkout flow and webhook handler. Apply this Skill to verify the handler reconciles state against Stripe event data, deduplicates deliveries, and keeps test/live credentials separated. ## Quick Start Review this pull request touching the Stripe checkout and webhook handlers for signature, idempotency, replay, and secret-boundary defects.