Sitelinks in ads let you show additional links to specific pages on your website and are an effective way to drive traffic to your business. Account level sitelinks 
started rolling out recently in the AdWords user interface. 
The AdWords API already supports sitelinks at the account level across all versions without any changes. You can use the 
CustomerExtensionSettingService to read and mutate the existing extension type 
SitelinkFeedItem, or associate sitelinks via 
Feed services.
If you have any questions, please let us know on the 
forum.
 - Danial Klimkin, AdWords API Team.
 - Danial Klimkin, AdWords API Team.