There are 2 key steps in performing an appraisal using the ValueChecker API. To get started, you will need an API key as described in the Authentication section. Here are the 2 steps needed to calculate an appraisal:
1

CP (Claimed Product)

Search by a query string and an optional category to identify the Claimed Product (CP). Example:
/query=iphone 11 64&client_category=Mobile%20Phones
Try it here: /product_search
response excerpt
{
  "product_name": "Apple iPhone 11 64GB",
  "pid": 1032089319
}
2

RP (Replacement Product)

Search using a pid to return Replacement Product (RP) suggestions and prices.
/prices?pid=1032089319&country=nl
For locale pricing purposes, country is also a required variable.
Try it here: /prices
response excerpt
{
  "claimed_product": {
    "master_name": "Apple iPhone 11 64GB",
    "pic_url": "https://img.valuechecker.net/,sxDbsr...",
    "product_name": "Apple iPhone 11 64GB Wit"
  },
  "grouped_prices": [
    [
      {
        "currency": "EUR",
        "in_stock": true,
        "offer_url": "https://{offer_url}/abcde123456abf1234",
        "price_date": "2020-08-26 16:45:45",
        "product": {
            "master_name": "Apple iPhone 11 64GB",
            "pic_url": "https://img.valuechecker.net/,sxDbsr...",
            "product_name": "Apple iPhone 11 64GB Wit",
        },
        "shop": {
            "shop_name": "belsimpel.nl",
        },
        "total_price": 694.00
        }
      }
    ]
  ]
}