Cart data for external attribution

[Veronika Miklínová]

For one conversion action we are using external attribution and therefore we adjust sent values by their weights. Now we want to implement sending cart data as well. Should we adjust any of the values for cart data (e.g. quantity, unitPrice) by the weigths or should we send them in full amount? If we send them by full amount, then the sent value for the conversion won't equal to sent quantity * unitPrice. Is it a problem?
example:
conversion value (original): 100
weight: 0.4
sent value (weighted conversion value): 40
unit price (original): 25
quantity (original): 4

[Google Ads API and AdWords API Forum]

Hi,

Thank you for reaching out to the Google Ads API support team.

Based on the provided information, I understand that you wanted to implement sending cart data. To provide you with the most accurate and helpful guidance, could you please clarify whether you are using the Google Ads user interface (UI) or the Google Ads API to send this data?

In order to assist you further, could you please elaborate more on your issue and provide us with the Google Ads customer ID and uncropped UI screenshot to understand the issue better.

You can send the details via the Reply privately to the author option or direct private reply to this email.

Thanks,

Google Ads API team.

[Veronika Miklínová]

We use Google Ads API. Below is an example of the body structure. If we have 5 gclid leading to revenue 100 EUR, we send each gclid with value 100/5 = 20 EUR and external attribution credit 1/5. Assume that the revenue 100 EUR consists of a product with unit price 25 and quantity 4. Should we send the items data not affected by the external  attribution credit  , i.e.  "items": [{ "productId": "A123", "quantity": 4, "unitPrice": 25}]  ? Or should we somehow adjust it so that quantity * unit price corresponds to the sent conversion value (100/5 = 20 EUR)?

{
"gclid": gclid,
"conversionDateTime": dateString,
...,
"currencyCode": "EUR",
"conversionValue": data.revenue / data.gclidCount,
"cartData": {
"merchantId": data.merchantId,
"feedCountryCode": data.feedCountryCode,
"feedLanguageCode": data.feedLanguageCode,
"localTransactionCost": data.localTransactionCost,
"items": [{ "productId": "A123", "quantity": 4, "unitPrice": 25}]

},
"consent": {...},
"externalAttributionData": {
"externalAttributionCredit": 1 / data.gclidCount,
"externalAttributionModel": "linearGclid"
}
}

[Google Ads API Forum Advisor]

Hi,

Thank you for reaching out to the Google Ads API support team.

According to the Google Ads API documentation the external_attribution_credit represents the fraction of the conversion that is attributed to the Google Ads click.

And I understand you're using the Google Ads API for external attribution, and want to know whether to adjust cart data values to match the partial conversion value you're sending. 

While our team specializes in Google Ads API related concerns and technical implementations only, we cannot advise on how to adjust your specific data. The data you use in your API calls is determined by your internal requirements and how you want to track your conversions. 

Additionally, I would recommend you to refer to this About conversions with cart data and About conversions with cart data diagnostics help center article for more detailed information especially which helps you understand your ad performance by providing details of products sold per transaction also on how to unlock sales, profit reporting, and insights for your Google Ads campaigns.

Thanks,
 

Google Ads API Team

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[2025-08-21 11:38:30Z GMT] This message is in relation to case "ref:!00D1U01174p.!500Ht01u4psj:ref" (ADR-00330604)