Google has discontinued its Custom Search Engine (CSE) product. For a fee, Google CSE allowed its customers to query a degraded version of the Google search index. That enticed potential competitors to rely on Google CSE rather than building full search engines with their own indexing capacity. Now Google is shutting them down by pulling out CSE. I am not sure that it’s legal for a monopolist to handle its potential competitors in this manner.
I used Google CSE in the Sane Climate Search and Google shut me off a few days ago. The Sane Climate Search is out. I did receive a notice more than a year ago.