NextJS@13 and KoaJS@2 integration to use koajs to handle nextjs api

app.ts

import Koa, { Context } from "koa";
import bodyParser from "@koa/bodyparser";
import registerRoutes from "./routers";
import Jwt from "koa-jwt";
const { THIRD_PARTY_APP_JWT_SECRET = "" } = process.env;

const koaApp = new Koa();
koaApp.use(bodyParser());

koaApp.use(async (ctx: Context, next) => {
  try {
    await next();
  } catch (err: any) {
    ctx.status = err.statusCode || err.status || 500;
    ctx.body = {
      message: err.message,
    };
  }
});

koaApp.use(
  Jwt({ secret: THIRD_PARTY_APP_JWT_SECRET }).unless({
    path: [
      "/api/third-party/open-api",
      "/api/third-party/docs",
      "/api/third-party/authentication/get-tokens",
      "/api/third-party/authentication/refresh-tokens",
    ],
  })
);

registerRoutes(koaApp);

export default koaApp;

entry.ts

// pages/api/third-party/[...all].js

import type { NextApiRequest, NextApiResponse } from "next";

import { createServer } from "http";
import koaApp from "@/backend/third-party/app";

const server = createServer(koaApp.callback());

export default async function handler(
  req: NextApiRequest,
  res: NextApiResponse
) {
  server.emit("request", req, res);
}

export const config = {
  api: {
    bodyParser: false,
  },
};

router.ts

import Router from "@koa/router";
import * as productService from "@/backend/third-party/services/productService";
import { ProductListResponseBody } from "../types";

const router = new Router({
  prefix: "/api/third-party",
});

router.get("/products", async (ctx, next) => {
  const { take, skip } = ctx.request.query;
  const { products, total } = await productService.findMany({
    take: Number(take),
    skip: Number(skip),
  });

  const response: ProductListResponseBody = {
    items: products as any[],
    total,
  };
  ctx.body = response;
});

router.get("/products/:productId", async (ctx, next) => {
  const { productId } = ctx.params;
  const product = await productService.findUnique({ id: Number(productId) });
  ctx.body = product;
});

export default router;