I have a problem I'm trying to tackle, and I think my answer to it has to do with using the Fulfillment API for Shopify and creating a Fulfillment Service, but things aren't very clear to me.
I have an app that when a store installs it, and enables it, we go ahead and create a specific product (with multiple variants) for that customer. This is a digital product, no shipping or tracking necessary. I want it so that when a user goes into the store and has this item added to this cart and finishes checking out, that the line item for this product is automatically set to fulfilled; however, I noticed that this isn't an option in Shopify. You can either set an item to be "manual" or fulfilled by a service.
After searching the API docs, it seems like I can achieve this by creating a Fulfillment Service for this store with a callback to my api. And when a user finishes checking out, my api will get hit with the Fulfillment Request. I can then accept this Fulfillment Request and tell Shopify that this line item has been fulfilled. Is this the correct way of doing things? Did I understand this correctly? If someone could help me out, that would be great.