AJAX Action Purpose Parameters Response app_add_to_cart Add product to cart product_id, quantity Success/error, updated cart app_remove_from_cart Remove product from cart product_id Success/error, updated cart app_get_cart Retrieve current cart contents None Cart items, totals, coupon data app_update_cart_quantities Update item quantities product_id, quantity Updated cart totals app_validate_coupon Apply discount coupon coupon_code Coupon data, new totals with discount app_remove_coupon Remove applied coupon None Cart recalculated without discount app_checkout_pay_now Process checkout with payment Billing info, payment details Order creation, payment processing