Subscription Contract
A Subscription Contract is Shopify's native record of a recurring agreement between a store and a customer — it stores what is being sold, how often it renews, the price, and the vaulted payment method, and Shopify uses it to create each recurring charge.
On Shopify, a subscription isn't a separate billing account bolted on by an app — it's a first-class object called a Subscription Contract. When a customer checks out with a subscription, Shopify creates the contract and vaults their payment method. From then on, Shopify itself generates each recurring order on schedule using that contract.
This matters because it means the merchant's checkout, payment processing, and order records all stay inside Shopify. A subscription app's job is to create and manage contracts — set up the plans, expose purchase options on the storefront, and give customers a portal to change things — not to run the billing. The money moves on Shopify's rails.
Curobi is built entirely on Subscription Contracts. Subscriptions are created at Shopify's native checkout and mirrored into Curobi for management, so Curobi never touches or stores card data and is never in the payment flow — which is also why it can charge 0% transaction fees.