You write your own handler and use the combination of the `operationId` field and an additional `x-handler` field to location your function. You can think of it like this: `pathHandler = require('${project-root}/handlers/${x-handler}').${operationId}`

The server provides dependency injection so that when you implement your handler-level function it can access several re-usable services to do the "real work". Generally my handlers are limited to getting the parameters off the request, passing them on to a (chain of) service(s) and getting the response back out to the client.

I hope the wiki has some good additional info if you're interested: https://github.com/blueoakjs/blueoak-server/wiki