APIs.json was designed to be a versatile API discovery format, not just a format for public API discovery via search engines like APIs.io. An APIs.json is meant to be a machine readable index of APIs within a single developer hub, providing information on the API endpoints as well as any other supporting resources--there is no reason that all of this can’t also be applied in a private setting.
APIs.json can easily be placed within a domain, subdomain, or at any network address, and be used to describe an internal collection of API resources, as well as bring in outside APIs. APIs.jsonbui excels at aggregating multiple, potentially disparate APIs, into a single coherent collection for use in development.
Using internal APIs.json files, a company, organization or governent agency can deploy an instance of an open source API search engine like APIs.io, or develop a custom API search tool that can aggregate the different APIs.json from each location, into a company wide API search and discovery destination.
An APIs.json provides a framework for referencing each APIs machine readable definition in Swagger, API Blueprint or RAML format, as well as other resources that internal developers will need to be successful, such as authentication info, SDKs, terms of service, and the multitude of other building blocks.
If you have public APIs, it will be a no brainer for you to generate machine readable API definitions for your APIs, and add them to a single, or potentially multiple APIs.json files for indexing. Even if you don’t have public APis, you can put APIs.json to work improving your internal API discovery, while also opening up your API resources to the other benefits of having machine readable API definitions.