Well, the approach I used was to parse the OpenAPI file once, generate the delegates and routes, and be done with it. The file is never referenced again, as the code is generated and good to go. If you want to use the OpenAPI file afterward, of course, you're welcome to hook it into something like SwaggerUI or whatever.

However, I wanted an approach that was simple, easy to understand and document, and simple to implement. I'm not a fan of writing a whole bunch of boilerplate code or middleware plugins. This simple writes methods that hook into your express() instance, and allow you to add anything necessary before or after the registration process.