We have noticed that for each purchase made through our store, Shopify appends a “checkout_session_token__cn__*” cookie. The accumulation of these cookies eventually leads to a “Cookie Too Large” error. We can clear the cookies, but it just starts again until the error happens again.
It looks like the “checkout_session_token__cn__” cookies contain the history of purchases by that user. Even purchases that have been fully checked out.
We are using the Storefront API with the checkout url provided by the API.
I am hoping someone can point in the right direction on how to resolve this.
After unblocking this endpoint it seems the cookies behave differently, so far this is working after about a week of no issues. For us this would happen at least a few times a week.
I’ve had tickets open with Shopify Plus support about this since Jan 10th, but I haven’t made much progress there and it’s still an issue.
The duplicate cookie issue can be easily replicated by placing a few orders in a row.
I’ve also noticed the 400 “Cookie Too Large” error is easier to trigger when the products in the cart have longer titles, because the “checkout_session_token__cn__” cookies contain the product names.