Reproduce the actual failure
Separate a signature error, wrong route, method mismatch, timeout, server error, and a successful delivery that fails to update application state.
Paddle · Next.js · Vercel · one existing route
Make the webhook verifiable before it changes subscription state.
A reachable URL is not proof of a safe billing event. This fixed milestone identifies the current failure, repairs one bounded route, verifies agreed sandbox events, and leaves a traceable handoff without asking for secrets in chat.
Sandbox firstOne routeClient-owned environmentNo secrets in messages
REPRODUCE→AUTHENTICATE→PROTECT STATE→PROVE
DELIVERY CONTROLS
Four gates between an incoming POST and trusted billing state.
Verify before parsing
Read the unmodified request body, verify Paddle-Signature with the destination-specific secret, and keep that secret inside the client-owned Vercel environment.
Make delivery repeat-safe
Acknowledge quickly, deduplicate by event_id, and use occurred_at where the existing data model must protect against out-of-order events.
Prove the agreed events
Run selected sandbox subscription or transaction events through Paddle's simulator and return traceable deployment evidence and remaining risks.
THE $250 BOUNDARY
Small enough to start. Specific enough to accept.
The title of a support request cannot diagnose the defect. The fixed scope covers one route and one evidence loop; anything broader is quoted only after the failure and current billing model are visible.
INCLUDED01
- One existing Next.js webhook route deployed on Vercel
- Current-failure reproduction and route/runtime diagnosis
- Raw-body and Paddle-Signature verification repair
- event_id deduplication and occurred_at ordering where the current data model supports them
- Agreed Paddle sandbox simulator events and an evidence handoff
- Changed-file summary, configuration checklist, and remaining-risk list
NOT INCLUDED02
- Tax, VAT, merchant-of-record, processor-selection, or legal advice
- A rewrite of the product's subscription, entitlement, or billing architecture
- Additional webhook destinations, providers, or unrelated application defects
- Production-revenue, approval, conversion, or zero-downtime guarantees
- Secrets pasted into Reddit, email, a ticket, or a shared document
ACCEPTANCE EVIDENCE
Not “it should work.” A result you can inspect.
The original symptom, reproduction path, and identified failure class.
Raw-body handling, destination-secret location, and signature-verification result without exposing the secret.
Duplicate and ordering behavior for the agreed event types, limited to the current data model.
Simulator evidence, deployed route, changed files, configuration checklist, and explicit remaining risks.
FIRST QUALIFICATION