Success & Cancel Redirects
Return customers safely without confusing navigation with settlement.
Configure success and cancel URLs in project settings. In production they must use HTTPS and their hostnames must be listed exactly in allowedRedirectDomains.
The paid checkout can return the customer to the configured success URL with invoiceId. The customer can use the cancel URL to leave an open payment request.
Success does not mean paid
Treat every redirect and query parameter as untrusted. Your backend must independently accept a verified signed webhook or call GET /v1/invoices/:invoiceId and require PAID before fulfillment.