We’re building a custom Shopify app to build a standalone storefront mobile app for a single merchant on Shopify Plus. Shopify remains the system of record for catalog, inventory, and fulfillment. Because we support auction and other purchasing formats, we need to process the payment using Stripe or our own payment provider (not Shopify Checkout). Then we create the completed order in the merchant’s store via the Admin API: orderCreate, or draftOrderCreate plus draftOrderComplete, so it can be fulfilled normally.
We’re aware the public apps require express written authorization to use an alternative to Shopify Checkout for payment processing, but it’s unclear if that applies to a custom app for one store use. We’d rather have that agreement in place than operate in a gray area. We’re on Plus plan. If we pay for Third-party transaction fees, does that authorize the use case? Who do we contact to start that conversation, and is there an existing classification - sales channel, Platform Service Partner, or something else - that fits this shape?