At a glance it looks like it's really just a proxy, that was limited to scholar.google.com and mutates the page slightly (adds a header, sci-hub links).
I'd imagine that would be quite hard: many university libraries have their own proxies which make sure that visitors to the library are able to access the content that the library has paid for, and often modifies Google Scholar (with their cooperation, I believe) to list links to accessible versions of the content next to search results.
> Too much attention is a bad thing, Sci-Bay decides to stop service for a while. Sorry.
Apparently I was not wrong.
This could be developed as a browser plugin that would be much harder or almost impossible for Google to prevent. Well, a Firefox browser plugin, a Chrome browser plugin presumably they wouldn't allow.
The page's HTML is the API. It's pretty easy to download a web page, parse the HTML and then extract specific bits of information from it. The browser does the same thing on the user's behalf, which is why it is called the user agent.
The issue is regarding: this service (Sci-Bay) depends on Google Scholar, yet there's no public API for Google Scholar that it could leverage. If it's scraping Google Scholar results, then it's likely a ToS violation and unlikely to last long.
Does google generally block proxy servers?