Get an update on console as soon as a slot opens up in https://selfregistration.cowin.gov.in/

cowin.js

/*
This script inspired by -> https://gist.github.com/debarko/45995919e2dc13d741b75215d393800d
Thanks to Debarko De.
It might be not working on an older browser.
Change the pincodes to your needs as per your city.

How To setup Video -> https://www.youtube.com/watch?v=3_N5FFegtI4

Steps to use
1. Update Pincode eg. ['110001', '110002'] and update age e.g 25
2. Login to https://selfregistration.cowin.gov.in/
3. Rigt Click on the website
4. Click on Inspect
5. Open the Console Tab on your Inspect window
6. Copy paste the contents of this entire file - cowin.js
7. Press Enter

It will run every 30 seconds and check for availability of slots.
*/

const personDetails = {
  pincodes: ['110002', '110003'], // Please insert your pincodes
  age: '25', // Please change your age
};
const date = new Date().toLocaleDateString().replace(/\//g, '-');
let trialCounter = 1;

const sleep = (delay) => new Promise((resolve) => setTimeout(resolve, delay));

async function fetchByPincode({ pincodes, age }) {
  const THIRTY_SECONDS = '30000';
  console.log('Check: ', trialCounter++);

  pincodes.forEach(async (pincode) => {
    const url = `https://cdn-api.co-vin.in/api/v2/appointment/sessions/public/calendarByPin?pincode=${pincode}&date=${date}`;
    try {
      const response = await fetch(url);
      if (response.status === 401) return;
      const data = await response.json();
      if (data !== undefined && data.centers.length !== 0) {
        for (let center in data.centers) {
          for (let session in data.centers[center].sessions) {
            if (
              data.centers[center].sessions[session].min_age_limit < age &&
              data.centers[center].sessions[session].available_capacity > 0
            ) {
              console.log(
                `Slot available, Book Now.. \nPincode : ${data.centers[center].pincode}\nCenter : ${data.centers[center].name}\nSlot Availabe : ${data.centers[center].sessions[session].available_capacity}`
              );
              let audio = new Audio(
                'https://suonoelettronico.com/waves22/sirena_ambulanza.mp3'
              );
              audio.play();
            }
          }
        }
      }
    } catch (e) {
      return;
    }
  });
  await sleep(THIRTY_SECONDS);
  fetchByPincode(personDetails);
}

fetchByPincode(personDetails);