I have built a B2C marketplace using Stripe's Connect platform. I currently use Stripe PaymentIntents (https://stripe.com/docs/payments/payment-intents) to collect customer payments; through the Stripe Connect platform I collect a per-transaction % fee, and the bulk of the payment goes to the business.
Now, I am looking to provide a seamless integration to get Shopify stores/products into my marketplace. I gather that I need a Shopify public app (maybe a sales channel app)? The examples I have seen don't seem to cover using Stripe's PaymentIntents API, which are the future for dealing with regulatory/authentication requirements, which Stripe's Charges API does not handle.
Looking forward to figuring this stuff out, to work better in an international, future-proof way.
receive per transaction % fee
potentially charge an app monthly/annual fee (maybe)
provide simple marketplace onboarding experience for Shopify stores: automatically create/sync marketplace presence and products