The model
Products describe what you sell; prices describe how much a buyer pays for it; checkout sessions and payment links turn prices into line items.- Product — what you sell (“Starter plan”, “Donation”). Carries name, description, images, unit label, kind, metadata, cross-sells.
- Price — belongs to one product; carries
unit_amount,currency,nickname, active state. A product can hold many prices (monthly vs annual, USD vs EUR) with one default. - Line item — a price selected for a specific checkout or link
(
{"price_id": "price_...", "quantity": 2}). Checkout sessions also accept inline line items for one-off amounts; payment links are always catalog-backed. - Optional item — a buyer-selectable add-on line: expedited service, setup packages, cross-sells.
npm install @ionicfi/sdk gives you typed calls for every request
below; the server SDK guide has details. Each example also
shows raw curl.

