I get these regular updates from FullContact when there is new information available about the contacts I have added to my contact list of people I care about. Anytime there is a new photo, social network, or other element of their contact information updated, I get notified, andI can choose to update it in my CRM.
Would someone go ahead and create this, but for OpenAPI Specifications? All you have to do is use Github, and build your own index of the websites of leading companies who are publishing APIs (common crawl is good start), and begin keeping track of ALL of the OpenAPI Specs, and API Blueprints that are increasingly spread across the web. Then you will need to develop some sort of API definition diff solution (which I've talked about before), and then send me any changes or updates that I do not have in my directory of API definitions--which you know, because you have indexed already.
You can offer premium services, like private repositories, and pathways to the wealth of API definition driven tooling out there. Again, this is something I could very well do, except I am one person, and not really interested in doing anything beyond all the work I already do. Especially if it involves taking VC money, scaling, and being any closer to the machine than I already am. So if you could get to work on this for me, and help solve this growing need in the API space, that would be great! Yeah. Also make sure and cut me in for 10% of all the $$$ you are going to make.