Okay that's a bit clearer problem statement, seems like just a dropshipping or fulfillment app.
To flesh out the requirements better I'd advise after researching more, go through experts.shopify.com and contact app devs who've made POD/dropshipping apps and get some consults to identify the hurdles you'll hit.
@BlanksfulPOD wrote:
Services will be like the sites above I mentioned which are print on demand.
" for those who use my service to integrate with their other e-commerce accounts like prinitful and customcat offer"
About wording, the ambiguity in the first description is your implying your a middleman between merchant and those other services and need to communicate with ALL of the parties. Whereas in this description you are a sole POD fulfillment so you only need to communicate between your business and the merchant so the other services are irrelevant.
@BlanksfulPOD wrote:
I can't find anything that allows this kind of integration where our customer links their e-commerce and when they link our product to their listing and it sells we then get the order on our end to print and send out.
It's not that you cannot find that kind of integration it's that you have to build that integration as an app using the shopify api. Meaning you are the integration provider ,right. There's no native integrator integration integration service on the shopify platform.
The closest to that idea would be third party low-code services like zapier,integromat but you still would have to build some sort of integration or api anyway for those third-parties to do the message passing on your side of things which can be an option if your targeting more platforms than just shopify.
If providing direct POD between the merchant and your business then to look at conversations/tutorials around fulfillment and dropshipping apps. There's a couple examples on github probably.
What your describing breakdowns to product sync, order passing, and fulfillment through the api.
https://shopify.dev/apps/fulfillment
https://github.com/Shopify/shopify-fulfillment-integration ( note: OLD )
https://github.com/Shopify/fulfillment-order-sample-app
The most rudimental system for fulfillment is custom fulfillment services that just send text of the order to an email address:
https://help.shopify.com/en/manual/shipping/fulfillment-services/custom
But there is no similar feature for a two way product sync beyond manually using CSV's to export/import.
Goodluck.
The description is also kinda tangential to making a marketplace/channel but that's more for merchants putting stuff on your platform for it to be viewed/purchase on your website so only "kinda" in the most ambiguous abstract sense.
