<?xml version="1.0"?> <!-- /** * Copyright © Magento, Inc. All rights reserved. * See COPYING.txt for license details. */ --> <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Api/etc/extension_attributes.xsd"> <extension_attributes for="Magento\Quote\Api\Data\CartInterface"> <attribute code="quoteApiTestAttribute" type="Magento\User\Api\Data\UserInterface"> <join reference_table="admin_user" join_on_field="store_id" reference_field="user_id" > <field>firstname</field> <field>lastname</field> <field>email</field> </join> </attribute> </extension_attributes> <extension_attributes for="Magento\Sales\Api\Data\InvoiceInterface"> <attribute code="invoiceApiTestAttribute" type="Magento\User\Api\Data\UserInterface"> <join reference_table="admin_user" join_on_field="store_id" reference_field="user_id" > <field>firstname</field> <field>lastname</field> <field>email</field> </join> </attribute> </extension_attributes> </config>