What about checkout — can I keep Magento's checkout?

You have three options:

• Build native headless checkout — Most expensive ($3k–$15k extra). Full UX control. Required for B2B / multi-step / saved-quote flows.
• Hand off to Magento checkout via SSO — Cheapest. Cart on headless, “Checkout” button redirects to Magento Hyvä Checkout (or Luma). Ugly URL transition but works in days, not weeks.
• Embed Magento checkout in iframe — Don’t. SEO mess, payment-gateway PCI complications.

For most $7,999 builds we recommend hand-off to Hyvä Checkout — it’s already 1-page and <1s, which beats most custom headless checkouts. Build native only if you’re in the Enterprise tier.