Export expressjs to JSON?

Hello!

I'm a newbie to Swagger.  I've worked up a embedded definition for one of our expressjs servers, and I'm quite happy with it.  Our QA expert tells me, however, that we could benefit from having the OpenAPI definition standalone in JSON format.

Is there a way to programmatically extract the OpenAPI metadata from the expressjs code such that I can automate it?

Thanks in advance!