In the interest of maintaining the integrity of autocomplete as part of its Search product, Google announced that it will be restricting unauthorized access to the unpublished autocomplete API starting Aug. 10, 2015.
Google said it wants to ensure that users experience autocomplete as it was intended -- as a service closely tied to search. What essentially happened is that the company never intended that autocomplete would exist disconnected from the purpose of anticipating user search queries.
According to the official announcement:
"Over time we've realized that while we can conceive of uses for an autocomplete data feed outside of search results that may be valuable, overall the content of our automatic completions are optimized and intended to be used in conjunction with web search results, and outside of the context of a web search don't provide a meaningful user benefit."
There have been multiple times in which the developer community's reverse-engineering of a Google service, via an unpublished API, has led to some impressive products however. The Google Maps API, for example, became a formally supported API shortly after some creative engineers combined map data with other data sources.
So, is this a harbinger of things to come? Will the digital community see more Google APIs close? The answer is likely a resounding no. Google still supports more than 80 APIs that developers can use to integrate Google services and data into their applications.