Google now lets you automate your Google Posts with the Google My Business API. Google quietly posted it in their what's new section saying you can now "create and update posts via the new Google My Business API." "Version 4.0 of the API adds support for posts, hotel amenities, and more," Google wrote.
The version 4 change log says "you can now create Posts on Google directly through the API." There are several other updates but this is the big one.
Now it is only a matter of time until the social publishing platforms add support to Google Posts, in addition to Twitter, Facebook, LinkedIn and other social platforms.
Forum discussion at Google+.