Xsolla will send a partner_side_catalog webhook that contains the user and project parameters to the webhook URL when a user interacts with the store.

Return a list of item_id or item SKU that are available to the user in response. In this case, you can also include information that a particular user can buy a certain product a specified number of times. This feature allows you to control the number and type of products that the user can add to the cart and buy.

It is recommended that the processing speed of the partner_side_catalog webhook is less than 3 seconds.