There are two distinct types of APIs I keep an eye on. One is what I call my life cycle APIs, which are the APIs of the service providers who are selling services and tools to API providers and developers. The second category is what I call my stack network, and these are the individual API providers, who offer a wide range of API resources--you can find both of these types on the home page of API Evangelist.
The 50+ life cycle APIs I track on can be used by companies to manage almost every stop along a modern API life cycle. In theory, all of these service providers have APIs. In reality, they do, but they do not practice what they preach and often do not make their APIs easily discoverable. I have said it a thousand times before--if you sell online services to API providers, you should have an API. Period.
At some point in the future, I will have profiled all of the companies included in my API life cycle research, like I did for API monitoring, and be able to provide a comprehensive API stack across all the providers for all stops along the life cycle. Ideally, each provider would have their own OpenAPI spec, but I'm still getting many of them to make their APIs public, convincing them of the importance of also having an API definition for their API will come next. Then I'll continue pushing on them to allow for the import / export of API definitions, so their customers can more easily get up and running with their services--if you need an example of this in the wild, take a look at Sandbox, or over at API Metrics.
I'd love to see someone take this idea and run with it beyond what I'm able to do as a one-man act. There are numerous API aggregation solutions already out there for financial, healthcare, images, documents, and more. What about an aggregated API across providers in the name of DevOps or microservices orchestration? An aggregated solution would allow you to automate defining of your APIs in multiple formats with API Transformer, deploy them using Docker or Heroku APIs, manage with 3Scale APIs, deploy sandboxes with Sandbox, monitor with Runscope, and almost every other stop along the life cycle.
I'm sure I've written this one up before, but I couldn't find it, so I wanted to get a fresh post up on the subject. With all the agile, orchestration, DevOps, microservices, continuous integration goingz on, having a coherent, cross-vendor API stack, and a suite of the usual analytics, billing, and other vital middleware services just makes sense. Let me know when you get up and running, and I'll send over my bank account information for the royalty payments. ;-)