Detecting 3rd Party Domains Accurately

Hi,

I am try to build out a testing platform on a private instance, and wanted to include some 3rd party intelligence.

Does anyone have any suggestions or best practices on how to accurately detect 3rd party results from the WPT results API?

I know there’s the cdn data - but CDN’s are often used as what I would call “second party” domains - for example if a site is a customer of Akamai or Limelight for example.

My current methodology is to ensure that the domain and domain’s cdn are different from the primary URL, and then use string matching to ensure that the domains are not similar - which might indicate that the domain is a customer of a CDN provider.

This is, of course very fuzzy and I was wondering if anyone had any better suggestions.

I am looking through the API docs too.

Thanks,