"Google has confirmed with Search Engine Land that they are discontinuing support for Google Site Search product. Google Site Search is a paid product that lets you power your internal web site’s search engine based on the Google search technology. Google charges based on monthly query volume for the product.Google to sunset Google Site Search by end of 2017
Google said they are directing those consumers to either the ad-powered product named free custom search engine or the new cloud search product.
Google will stop fully supporting the Google Site Search product by the fourth-quarter of 2017."
Wednesday, February 22, 2017
Google to sunset Google Site Search by end of 2017 (Search Engine Land)
Also see Google Plans To Discontinue Yet Another Product (Fortune)