Google is giving us about a year to switch over from the old Google AdWords API to the newer Google Ads API. The Google Ads API replaced the AdWords API when Google released it as a beta I believe in 2019.
Google made the Ads API available to all in September 2020 and just this week released version 7.0 of the Google Ads API.
Now Google is giving those who are still using the Google AdWords API a year to migrate to the newer Google Ads API. Google said "if you are a developer currently using the AdWords API, you need to upgrade to the Google Ads API by April 27, 2022. On that date, the AdWords API will sunset and requests to the AdWords API will fail."
Google said the reason is version 7 of the Google Ads API now gives you feature parity with the AdWords API making it possible for all developers to upgrade with a few exceptions listed at the top of the Migrating Features guide. You can see those exceptions over here.
I recommend you start this process sooner than later and not leave it to the last minute.
Forum discussion at Twitter.
