But just looking at it as a way to just mock an API ignores the possibilities. The idea is that by having a formal definition of an API, not only can you consider and develop the API interface in isolation from your implementation, but you can use the same language to generate documentation, client SDKs, and server-side routing and request/response validation.
That final aspect is the thrust of swagger-node (https://www.npmjs.com/swagger) where we can take a Swagger document and use it as the basis of a dynamic (ie. not code-gen) Node.js API server. In the future, we'll also move beyond validation and routing to utilize extensions to declaratively provide other API services that are necessary but tangential to the business logic.
That final aspect is the thrust of swagger-node (https://www.npmjs.com/swagger) where we can take a Swagger document and use it as the basis of a dynamic (ie. not code-gen) Node.js API server. In the future, we'll also move beyond validation and routing to utilize extensions to declaratively provide other API services that are necessary but tangential to the business logic.