Squarespace typically integrates with best-in-class services for optimal onboarding, setup and UX. ShipStation is best in class for fulfillment, which is why I think they partnered with them.

But I agree with some of the comments. The restricted API kills all workflow-related processes. Regardless of shipping and fulfillment, there's tons of business processes that need to be done with orders and you can't do any of it with Squarespace. I've worked with dozens of clients who started on Squarespace and moved to other platforms simply because of Commerce restrictions.

I don't understand it either really. It's a one way exclusivity agreement so it's making ShipStation money by bringing them new accounts, but I don't see how it helps Squarespace to only offer one fulfillment option. I assume ShipStation is paying Squarespace. I see this type of decision and it makes me very wary of using a platform that would do such a thing to a seemingly critical component.