Main topic: A print-on-demand provider for personal/pet care products seeks guidance on building an app so merchants can integrate and sell products, similar to Printful but for cosmetics.
Guidance provided: Start with Shopify’s developer documentation for building apps; this is a highly technical project requiring a software developer. A step-by-step tutorial for creating an example Shopify App is linked.
Technical approach: Use the Shopify API (Admin GraphQL) to programmatically create and manage products; the productCreate mutation is specifically referenced for adding products to a merchant’s store.
Publication: Once the app is built, submit it for review to the Shopify App Store.
Key steps:
Status: No decision or resolution yet; clear next steps identified, pending development and submission.
We own a print-on-demand serivce allowing people to create and sell personal care and pet care products. How do we go about developing an app so that customers can easily integrate to their website and sell their products?
For reference, exactly like printful but for cosmetics instead.
Hi there 
I would recommend starting out with the developer documentation about building Shopify Apps. Building a Shopify App is highly technical and will require the expertise of a software developer. Here is a tutorial that guides you through building an example Shopify App.
Your Shopify App would use the Shopify API to create and manage products that the merchant is selling.
Once the App has been built you will submit it for review in the Shopify App store.