Foxy.io

Foxy.io is a developer-first checkout platform that runs independently of your site infrastructure, letting you build checkout into custom applications, static site generators, or headless commerce setups. It handles digital product delivery, recurring billing, complex pricing models (tiered, volume discounts, bundles), and stores all transaction history without requiring your own payment processor infrastructure.

This fits teams building course platforms on custom tech stacks who need a production-grade checkout that doesn't lock them into a specific CMS. The API-first model means you control the UX entirely while offloading payment compliance, fraud prevention, and subscription logic to Foxy's hosted service.