My team and I are building a free, third party, calculator tool that enables users to calculate metrics using their store's data.
We are looking for ways to pull in the necessary data and perform the calculation to show users... so far the best we've come up with is asking the users to export a report from Shopify and upload it into our application.
Looking for a user experience similar to this:
1. User opens our tool, application is hosted on custom-domain.com
2. Somehow the user authenticates or logins in to Shopify, or approves our app temporary access to their data.
3. Our app performs the calculation for the user, ending data access
Any ideas as to how this authentication or access of data can be facilitated?