How it works

Call tiun.checkout({ productId }) and tiun opens a full-screen overlay that runs the entire purchase and sign-in experience. You don't build forms, validate inputs, or host payment fields yourself.

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What the overlay contains

For a subscription product, the overlay walks the user through:

• Plan details — product name, pricing, billing interval, and any trial info.

• Email entry — the user is identified by email as part of checkout.

• Payment method selection — credit/debit cards, PayPal, Apple Pay, Google Pay, PrePaid (tiun credits), and Twint, where enabled and regionally available.

• Terms acceptance and a clear pay action.

A Login affordance also appears at the bottom of the overlay so a visitor who already has a tiun account can sign in instead of entering email as a new customer.

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Identity verification

• If the email is recognized (returning user), tiun sends an OTP code to the phone number already linked to the account.

• If the email is not recognized, an additional overlay asks for the user's phone number, then sends an OTP to validate and link it before payment continues.

Checkout authenticates as part of the same flow — there's no separate sign-up step. See Authentication / How it works for the broader identity model.

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Managed by tiun

The overlay is owned and updated by tiun: layout, validation, compliance copy, and payment UI stay consistent without changes in your codebase. The flow also surfaces in-overlay help — including an explainer video link and "More info" affordances where appropriate — so common questions are handled inside checkout.

For what happens after the user completes checkout (the journey, session restore, logout), see Subscriptions. For the resulting entitlements on the user, see Product access.