This is for the API forward base on the Express node framework.

const  express = require("express");
const  app = express();
app.get("/api", (req, res) => {
  res.send("Hello !");
});

app.listen(3000, () => {
  console.log("Listening on port 3000...");
});

export PORT=8000  //Mac 
set PORT=8000     //Windows

• Express:
  Back-end API framework
• nodemon:
  Run npx nodemon FILENAME.js for watch the changes and run the service.
• joi:
  The request validation check package.
• cors:
  The CORS error configuration.
• urlencode:
  The urlencode / urldecode package. (rawurlencode)

Official Library:

• https://www.npmjs.com/package/express

Request Document:

• http://expressjs.com/en/4x/api.html#req