how to build shopify app that change product price based on product personalizer

[Sanjay-Makwana]

Build shopify app with Shopify CLI 

node and php

how to build shopify app that change product price based on product personalize

 how do access the cart items.

[HappyPoints]

- You should get data about the product here

- Here's an example of a simple mutation to update the price for a variant. This mutation includes the variant_id, variant_price, and any errors in the response:

mutation productVariantUpdate($input: ProductVariantInput!) {
  productVariantUpdate(input: $input) {
    product {
      id
    }
    productVariant {
      id
      price
    }
    userErrors {
      field
      message
    }}}

Variables:

{
  "input": {
    "id": "gid://shopify/ProductVariant/31365788074006",
    "price": 10
  }
}
 

[Sanjay-Makwana]

@HappyPoints  Thanks for the answers. 

I want to take user input like their name and size printing one input user can upload the picture based on both inputs I need to change the product price. Finlay price goes to the cart item. and order with that amount customer needs to pay that amount. 

I know the cart goes product variant id and qty but I also need to change the product price when a customer does the Add to cart.
I can see that some apps do a similar feature as I want to build https://apps.shopify.com/custom-price-calculator  and https://apps.shopify.com/customer-pricing  those app solution does not help.