When customers purchase on our website, we are collecting their data (name, address, etc) and then passing it to auth.net via Access Hosted. We have a page that retrieves the webhook data when the transaction is appoved. After the transaction is made, we are trying to display a page with links based on the product they purchase.

The problem is, as we understand, the webhook gets the latest transaction, however if three people purchase on our website at the same time, how do we know which webhook goes to which person? We can't store the customer's data in session because the user goes to the payment form on auth.net. If there was some kind of link between the user's browser and the webhook, we would know who purchased what. It would help to be able to query the webhook somehow, like "Get webhook with invoice 123456". As of now it seems totally random which data we get back from the webhook.

The way this used to work with us is that we would send auth.net the user's data via the ID field. After the transaction was approved, they would pass that ID back to us so we can link them to the purchase and the POST data does not leave the user's browser.