I need your help. I am looking to create a custom search engine.
I am currently looking at using the Google Custom search API. I tried looking into this but I couldn't find anything concrete.
Is there any way to setup related search words on a Google Custom search website? Is there any API that can generate "searches related to"?
Yes, there is a service by SimilarSites which outputs data very similar to the Google Related API, but they use their own proprietary algos.
I'm not pretty sure what you mean by "searches related to". Nevertheless for every single request in CSE API you can specify the following parameters:
More infos can be found here.
May be it will be useful for you.
There are several interesting APIs that can help you here.
Keywords Competitors API - This is an API that let you query a domain and get all the other domains that are competing on the same paid or organic search keywords.
Search Keywords API - Another API that will provide all the leading keywords (paid and organic) for a given domain. This can even be broken down to specific countries.
SimilarWeb API - Get more websites that are similar to a given domain, based on many different factors including keywords and tags.