vercel.json

gistfile1.txt

import { Feed } from "feed";
import axios from 'axios';

const name = "SITE_NAME";
const url = "https://yourURL.com"
const backendURL = "https://yourWordpressURL.com"
const email = "you@yourDomain.com"
const imageUrl = backendURL + "/TO_LOGO"
const description = "SITE_DESCRIPTION"

module.exports = (req, res) => {
  const feed = new Feed({
    title: name,
    description: description,
    id: url,
    link: url,
    language: "en", // optional, used only in RSS 2.0, possible values: http://www.w3.org/TR/REC-html40/struct/dirlang.html#langcodes
    image: imageUrl,
    favicon: url + "/favicon.ico",
    copyright: "All rights reserved 2020, " + name,
    generator: "awesome", // optional, default = 'Feed for Node.js'
    feedLinks: {
      json: url + "/feed",
      atom: url + "/feed"
    },
    author: {
      name: name,
      email: email,
      link: url + "feed"
    }
  });
  
  axios.get(backendURL + '/wp-json/wp/v2/posts')
  .then(function (response) {
    // handle success

    response.data.forEach(post => {
      feed.addItem({
        title: post.title.rendered,
        id: post.link.replace(backendURL, url),
        link: post.link.replace(backendURL, url),
        description: post.excerpt.rendered,
        content: post.content.rendered,
        author: [
        ],
        contributor: [
        ],
        date:  new Date(Date.parse(post.date_gmt))
      });

   });

    res.setHeader("Content-Type", "application/xml")
    res.status(200).send(feed.atom1())
  })
   
  }

vercel.json

{
  "version": 2,
  "builds": [
    {
      "src": "api/*.js",
      "use": "@now/node"
    },
    {
      "src": "package.json",
      "use": "@frontity/now"
    }
  ],

  "routes": [
    {
      "src": "/feed",
      "headers": { "cache-control": "no-cache" },
      "dest": "/api/feed.js"
    },
    ...
  ]
}