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name: billing description: Billing - Stripe, webhooks, subscriptions. Use when implementing payments.

Billing Guideline

Tech Stack

• Payments: Stripe
• Workflows: Upstash Workflows + QStash
• Database: Neon (Postgres)
• ORM: Drizzle

Non-Negotiables

• Webhook signature must be verified (reject unverifiable events)
• Stripe event ID must be used for idempotency
• Webhooks must handle out-of-order delivery
• Subscription state changes must be audit-logged
• Payment failures must trigger appropriate user communication

Context

Billing handles the payment processing mechanics — webhooks, subscription lifecycle, payment methods. It's the plumbing that moves money. Pricing strategy and entitlements live in pricing.

The platform owns billing logic. Stripe is a payment processor. All billing configuration must be in code, not Stripe dashboard.

Driving Questions

• Are webhooks handling all subscription lifecycle events?
• What happens when payment fails mid-cycle?
• How are disputes and chargebacks handled end-to-end?
• Can failed webhooks be safely replayed?
• Where could revenue leak (failed renewals, unhandled states)?