Note: This site explains how to integrate the Google AdWords API, which is no longer being actively developed, with v2 of the Content API for Shopping, which has been deprecated. We recommend migrating to the Google Ads API and v2.1 of the Content API for Shopping.
Only one Merchant Center account is considered authoritative for a given merchant website. To prove that you are the authoritative source of information, you must verify the URL that is configured for your Merchant Center account to show that you have access to the website, and then you must claim that URL to assert that you are the authoritative source of product information.
To automate Merchant Center website claiming, you'll first need to use the Google Site Verification API to verify that you have access to the website you want to claim. Once this is done, then you can use the Content API for Shopping to claim the website.