Shopify Billing is the system that Shopify provides for apps in the Shopify App Store to charge merchants, the store owners who install the apps. Every app published on the Shopify App Store must use a billing solution from Shopify. Charges appear on the merchant's normal Shopify invoice, Shopify collects the money and pays out the developer's share, and Shopify handles chargebacks (card payments that the card holder disputes and the bank reverses).
There are two methods. With Shopify App Pricing, the default for new public apps, the developer defines plans in the app submission form; Shopify hosts the plan selection page and runs free trials, proration, upgrades and downgrades. It supports free, monthly and annual plans and usage charges, which the app reports as billable usage events through the App Events API. With manual pricing (legacy), the app creates recurring, usage or one-time charges with GraphQL mutations such as appSubscriptionCreate (GraphQL is a query language for APIs), and the merchant approves each charge on a page that Shopify hosts.
Pricing is a revenue share above a lifetime revenue threshold, plus a processing fee on all billing.