webhook-implementation

Webhook Implementation

Builds robust Stripe webhook handlers. Match the project's stack or ask users (Next.js route, Express, Supabase edge function).

Must-haves

1. Raw body for signature verification (no JSON pre-parse)
2. stripe.webhooks.constructEvent(body, sig, secret)
3. Idempotency -- dedupe by event.id (store processed IDs)
4. Return 200 fast; heavy work async
5. Handle only subscribed events; ignore rest gracefully

Core events (subscription SaaS)

Event	Handler action
checkout.session.completed	Provision access, save customer/sub IDs
customer.subscription.updated	Sync plan + status
customer.subscription.deleted	Revoke access
invoice.payment_failed	Trigger dunning email/banner
invoice.paid	Confirm renewal

Pattern (pseudocode)

event = constructEvent(rawBody, sig, secret)
if alreadyProcessed(event.id): return 200
switch event.type: ...handle...
markProcessed(event.id)
return 200

Verify

Use Stripe CLI stripe listen / stripe trigger, or check webhook-reliability after deploy.