Is it possible to access any information about a merchant's customers using the Square Connect API? The most ideal piece of information would be the email address customers enter for their receipt, but but some type of unique customer id would be nice to determine repeat customers.
Looking through the Square Connect API Documents there are no endpoints for customers and Payment objects do not include any of this information. Is there another Square API with this capability?
Not at this time. Regarding customer email addresses obtained for receipts, from the Square help center:
Based on our privacy policies and governing regulations, we cannot share cardholders' personal information with our customers when contact information is only collected for receipt purposes.
However, I'll pass this feedback along to the Connect API engineering team (I write the docs).