We are using an iframe with a product configurator which we then used to add items to the cart. The iframe calls an API endpoint on our end, but we can’t control what the requests look like, which means that we can’t add any request headers and therefore can’t access the session with the current cart.
It is possible to pass custom variables ass a payload from the iframe. Is there anyway we can retrieve the cart using customer ID or similar?
No, it’s not possible to access the cart from another session.
What you can do is to add an variable into the iframe that will act as a key. The api endpoint will store the information from the iframe request based on the key. When the regular page is reloading you can fetch the stored info based on the key and compare/add items to the user cart.