RAW BODY LOST
Framework body parsing mutates the payload before signature verification.
STRIPE / NEXT.JS / VERCEL
WEBHOOKS
THAT SURVIVE
PRODUCTION.
A free payload diagnostic and a tested reliability kit for the payment code that cannot fail twice.
15 TESTS7 CORE EVENTS0 PAYLOADS UPLOADED
FAILURE MAP / 00
THE HAPPY PATH
IS NOT THE SYSTEM.
DUPLICATE DELIVERY
Stripe retries; a successful side effect runs twice without a persistent event key.
ACK BEFORE COMMIT
A 200 response lands before your database transaction survives.
LOCAL ≠ VERCEL
Secrets, runtime, paths, and deployment URLs diverge from the local tunnel.
FREE TOOL / 01
EVENT PAYLOAD
DIAGNOSTIC
Paste a Stripe event. Analysis runs inside your browser; the payload is never transmitted or stored.
100/100
● EVENT ENVELOPE VALID
- TYPE
- checkout.session.completed
- EVENT ID
- evt_1QzExample
- IDEMPOTENCY
- USE EVENT ID AS UNIQUE KEY
All envelope checks passed. Signature verification still requires the raw HTTP body and endpoint secret.
PRO KIT / 02
SHIP THE BORING
PART ONCE.
Production-focused source code. No subscription, runtime dependency, account, or lock-in.
$5 USDC / ONE TIME
- Typed event router with raw-body verification
- Persistent idempotency patterns for Postgres and Upstash
- Checkout, invoice, and subscription handlers
- Vitest fixtures for success, retry, duplicate, and failure states
- Next.js App Router + Vercel deployment templates
- Environment validator and launch runbook
- Commercial use in unlimited projects
x402 on Base · ZIP releases only after settled payment
DESIGN RULE / 03
“Return success only when you know exactly what happened—and make every retry harmless.”VIEW THE FREE CORE ON GITHUB ↗