Using the PutListingsItem method to send a LISTING_OFFER_ONLY request based on the ASIN of items not currently in our catalogue.

[RamshackleJoe]

Hello,
I hope you can help...

We have a list of products that we have identified as a match to existing ASINs on the Amazon website that we would like to sell from our market place store using the PutListingsItem method but I cannot see how to add the ASIN in to the ParameterPutListingItem parameter.

I have included samples of my code below, would anyone be able to offer advice on what I would need to do?
Thanks in advance.

api = new AmazonConnection(new AmazonCredential()
{
    AccessKey = Credentials["AccessKey"].ToString(),
    SecretKey = Credentials["SecretKey"].ToString(),
    RoleArn = Credentials["RoleArn"].ToString(),
    ClientId = Credentials["ClientId"].ToString(),
    ClientSecret = Credentials["ClientSecret"].ToString(),
    RefreshToken = Credentials["RefreshToken"].ToString(),
    MarketPlaceID = Credentials["MarketPlaceID"].ToString(),
    Environment = (Constants.Environments)Convert.ToInt16(Credentials["Environment"])
});
        
/* Note: System.Data.DataRow r has been created outside this sample code  */    
string sku = r["sellersku"].ToString();
string ASIN = r["samASIN"].ToString();  //I want to use this string to identify a product that already exists on Amazon.
FikaAmazonAPI.Parameter.ListingItem.ParameterPutListingItem toList = new FikaAmazonAPI.Parameter.ListingItem.ParameterPutListingItem
{
    sellerId = SellerID,  //Held elsewhere in the class.
    sku = sku,
    marketplaceIds = marketplaceIds, //Held elsewhere in the class.
    listingsItemPutRequest = new FikaAmazonAPI.Parameter.ListingItem.ListingsItemPutRequest() 
    {
        productType = "PRODUCT",
        requirements = FikaAmazonAPI.Parameter.ListingItem.Requirements.LISTING_OFFER_ONLY,                        
    }
};

toList.listingsItemPutRequest.attributes = new List<object>()
{
    new
    {
        key = "condition_type",
        items = new List<object>
        {
            new
            {
                value = "new_new",
                marketplace_id = MarketPlace.UnitedKingdom.ID
            }
        }
    },
    new
    {
        key = "list_price",
        items = new List<object>
        {
            new 
            {
                currency = "GBP",
                value = Convert.ToDouble(r["now_price"])
            }
        }
    },
    new
    {
        key = "fulfillment_availability",
        items = new List<object>
        {
            new
            {
                fulfillment_channel_code = "DEFAULT",
                quantity = Convert.ToInt32(r["stock_level"])
            }
        }
    }
};

[TechyChap]

There are 2 approaches to this. You can send the merchant_suggested_asin or you can send the externally_assigned_product_identifier and get Amazon to match it up.

   "externally_assigned_product_identifier": {
      "$comment": "This attribute indicates the type of external ID (barcode) and corresponding value that is being used to identify the product",
      "title": "External Product ID",
      "description": "Provide the external ID (barcode) type and corresponding value that is being used to identify the product",
      "examples": [ "714532191586" ],
      "type": "array",
      "minItems": 1,
      "minUniqueItems": 1,
      "maxUniqueItems": 1,
      "selectors": [ "marketplace_id", "type" ],
      "items": {
        "type": "object",
        "required": [ "marketplace_id", "type", "value" ],
        "properties": {
          "type": {
            "title": "External Product ID Type",
            "description": "Select the type of external ID (barcode) that is being used to identify this product",
            "editable": false,
            "hidden": false,
            "examples": [ "UPC" ],
            "type": "string",
            "enum": [ "ean", "gtin", "minsan_code", "upc" ],
            "enumNames": [ "EAN", "GTIN", "MINSAN", "UPC" ]
          },
          "value": {
            "title": "External Product ID",
            "description": "Provide the corresponding external product id value based on the type that was selected",
            "editable": false,
            "hidden": false,
            "examples": [ "714532191586" ],
            "type": "string"
          },
          "marketplace_id": { "$ref": "#/$defs/marketplace_id" }
        },
        "additionalProperties": false
      }
    },
    "merchant_suggested_asin": {
      "$comment": "This attribute represents the merchants suggested ASIN",
      "title": "Merchant Suggested Asin",
      "description": "If you believe that an ASIN already exists for your product, then please provide it here. Otherwise leave blank and the system will look for a match based on the External Product ID that you provided",
      "examples": [ "B007KQBXN0" ],
      "type": "array",
      "minItems": 1,
      "minUniqueItems": 1,
      "maxUniqueItems": 1,
      "selectors": [ "marketplace_id", "value" ],
      "items": {
        "type": "object",
        "required": [ "marketplace_id", "value" ],
        "properties": {
          "value": {
            "title": "Merchant Suggested Asin",
            "description": "If you believe that an ASIN already exists for your product, then please provide it here. Otherwise leave blank and the system will look for a match based on the External Product ID that you provided",
            "editable": false,
            "hidden": false,
            "examples": [ "B007KQBXN0" ],
            "type": "string",
            "minLength": 10,
            "maxLength": 10,
            "maxUtf8ByteLength": 40
          },
          "marketplace_id": { "$ref": "#/$defs/marketplace_id" }
        },
        "additionalProperties": false
      }
    },