slate/pages/api/_.js

import "isomorphic-fetch";

import * as MW from "~/node_common/middleware";

const initCORS = MW.init(MW.CORS);

export default async (req, res) => {
  initCORS(req, res);

  return res.status(200).json({ decorator: "SERVER_HEALTH_CHECK", data: { slate: true } });
};