What payment data we store (and why card data lives with Stripe)
HIIE does not store your payment card data. Payments are handled by Stripe, and card details stay with Stripe rather than HIIE.
No card storage
The Security page states plainly that HIIE does not store payment card data. Payments are processed by Stripe, which is a PCI-DSS Level 1 provider — the highest level of payment-industry compliance. Keeping card data with Stripe means sensitive payment details never touch HIIE's own systems.
How billing works
Billing checkout uses Stripe. Starting a subscription plan or a one-time credit top-up opens a Stripe Checkout session, and after checkout you're returned to your dashboard. Stripe must be configured for this to run; otherwise checkout reports that Stripe isn't configured.
Grants are applied through a Stripe webhook that is secured by signature verification. In production, if the webhook secret isn't set, it fails closed and refuses unsigned webhooks, and duplicate event deliveries are handled idempotently so credits and plan changes are never double-applied.
When you don't pay at all
If you bring your own provider API key, HIIE itself is free — credits and subscriptions apply only when you use HIIE-managed infrastructure. Your BYO keys are encrypted and used server-side only.
The bottom line
The only payment-related data flowing through HIIE is what's needed to trigger and reconcile a Stripe transaction. The actual card data lives with Stripe, under PCI-DSS Level 1 compliance, not with HIIE.