I'm interested in using the carts/update webhook to listen for shopping activity by our customers. Looking at the sample payload on the developers page, it doesn't seem like there's any user identification (i.e. email address, customer ID, etc.) provided, preventing me from being able to identify which customers initiated the cart activities. Is that correct? Or is the sample payload not showing all the metadata that can be passed? For example, is the sample representing a customer who hasn't identified themselves/logged in?
To confirm, these are the expected fields being provided in the payload for a cart/update webhook event. Fundamentally, a cart is made up by a collection of line items, which doesn't have to be associated to a specific customer. Even upon logging in, the customer data still wouldn't be held within the cart json, so exploring alternatives to webhooks would be suggested if tracking customer specific data is your priority.