Example Swagger Framework usage in Koa

swagger-koa.js

/**
 * Koa middleware for Swagger Framework.
 */

'use strict';

/**
 * Initialize a new `Koa`.
 *
 * @param {Framework} framework
 * @api public
 */

function Koa(framework) {
  if (!(this instanceof Koa)) {
    return new Koa(framework);
  }

  this.framework = framework;
  this.framework.setup();
}

/**
 * Create and return Koa middleware.
 *
 * @api public
 */

Koa.prototype.middleware = function() {
  var options = {};

  options.setup = function(req, res) {
    var sf = req.sf;

    req.sf.responseMessage = function(reply) {
      sf._ctx.response.status = reply.statusCode;
      sf._ctx.response.body = reply.body;
      sf._done(null, true);
    };
  };

  var route = this.framework.router.setup(options);

  return function *(next) {
    var ctx = this;

    var match = route(ctx.req, ctx.res);
    var sf = ctx.req.sf;

    // match path
    if (match && match.node && match.node.handle) {
      sf._ctx = ctx;
      sf._params = match.param;

      function handled() {
        return function(cb) {
          sf._done = cb;
          match.node.handle(ctx.req, ctx.res, cb);
        }
      }

      if (yield handled()) return;
    }

    yield next
  };
};

/**
 * Expose swagger.
 */

exports.Koa = Koa;

I am not seeing here where you are making a reference to swagger at all. Is this just making a koa instance compatible with an existing node/swagger project? Can you elaborate how this is used?