---
name: "stripe-billing"
description: "Implement Stripe Checkout sessions, subscription upgrades, customer portals, and idempotent webhooks."
---

# Stripe Elements & Webhook Idempotency

Guarantees zero double-billing bugs by verifying Stripe cryptographic webhook signatures and tracking events.

## Instructions and Rules
1. Read existing repository patterns before making modifications.
2. Adhere strictly to the workspace directory boundaries.
3. Verify changes with unit or integration tests before concluding.