I'm trying to add to cart a product with custom and base price. It's working file.

The problem is that Stripe checkout module has an update button that adds the address of a guest customer to billing address, and when that happens my product's price get backs to original.

Here is my controller where I set the custom price.

public function execute(){
        $request = $this->getRequest()->getPostValue();
        $product_id = $request['product_id'];
        $price = $request['grand_total'];
        $params = array(
            'formKey' => $this->formKey,
            'product_id' => $product_id,
            'qty' => 1

        $productFactory = $this->product->create();
            $product = $productFactory->load($product_id);
        catch(\Exception $e){
            return $request;

Is there any solution for this that does not involves modifying Stripe's module ?

Maybe changing product's price from database dinamically?

Thanks and greetings!

1 Answer 1


Step 1: Create Events/xml File

Firstly, you need to create events/xml in the folder Vendor/Module/etc/frontend and use event checkout_cart_product_add_after

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
    <event name="checkout_cart_product_add_after">
        <observer name="customprice" instance="Vendor\Module\Observer\CustomPrice" />

Step 2: Create CustomPrice.php File

Now, you have to create CustomPrice.php file that override your price in the Observer Folder.

     * Vendor Module CustomPrice Observer
     * @category    Vendor
     * @package     Vendor_Module
     * @author      Vendor Module
    namespace Vendor\Module\Observer;
    use Magento\Framework\Event\ObserverInterface;
    use Magento\Framework\App\RequestInterface;
    class CustomPrice implements ObserverInterface
        public function execute(\Magento\Framework\Event\Observer $observer) {
            $item = $observer->getEvent()->getData('quote_item');         
            $item = ( $item->getParentItem() ? $item->getParentItem() : $item );
            $price = 100; //set your price here

I think after that your stripe module will not change price. Note: According to your need for setting a custom price for one or more products, you can manipulate this by adding conditions.

accept solution if works for you.

  • Hi, it worked, but do you know how can I send $price value to the Observer? I don't know how to send paremeters to observer. Greetings! May 26, 2021 at 1:26
  • You can create a session variable and unset it once price set successfully.. May 26, 2021 at 3:11

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