Do we have vaccination slots for 25 year olds yet?

index.js

/**
 * run `npm init -y`
 * run `npm i node-fetch`
 * run `node index.js`
 * turn Slack notifications on
 * 
 * Get cowinUrl from the DevTools' network tab
 * Get authorization string from the Request Headers as the value of authorization header of the network request for cowinUrl. If this expires, the script will stop working. You'll have to log in again and get a new value for this.
 */

const fetch = require('node-fetch');

const slackWebhookUrl = ''; // Your Slack webhook URL
const authorization = ''; // Bearer auth string
const cowinUrl = 'https://cdn-api.co-vin.in/api/v2/appointment/sessions/calendarByDistrict?district_id=265&date=29-04-2021'; // This is for Bangalore Urban on 29th April

function sleep(time) {
  return new Promise((resolve) => {
    setTimeout(resolve, time);
  });
}

async function main() {
  while (true) {
    const d = new Date();

    console.log('Checking at', d.toLocaleTimeString());
    const changed = await check();

    if (changed) {
      break;
    }

    // sleep for 5 mins
    await sleep(300000);
  }
}

function sendToSlack(message) {
  return fetch(slackWebhookUrl, {
    body: JSON.stringify({
      text: message,
    }),
    headers: {
      'Content-Type': 'application/json',
    },
    method: 'POST',
  });
}

function uniq(arr) {
  const s = new Set(arr);
  return Array.from(s);
}

function getSlotsFor25(res) {
  let centers = [];

  if (!('centers' in res)) {
    return centers;
  }

  centers = res.centers.filter((centre) => {
    return centre.sessions.some((session) => session.min_age_limit <= 25);
  });

  return centers.map((c) => {
    return {
      name: c.name,
      pin: c.pincode,
      vaccines:
        uniq(c.sessions.map((s) => s.vaccine).filter(Boolean)).join(' ') ||
        'Not specified',
    };
  });
}

function check() {
  return fetch(cowinUrl, {
    headers: {
      accept: 'application/json, text/plain, */*',
      'accept-language': 'en-US,en;q=0.9',
      authorization,
      'cache-control': 'no-cache',
      pragma: 'no-cache',
      'sec-ch-ua':
        '" Not A;Brand";v="99", "Chromium";v="90", "Google Chrome";v="90"',
      'sec-ch-ua-mobile': '?0',
      'sec-fetch-dest': 'empty',
      'sec-fetch-mode': 'cors',
      'sec-fetch-site': 'cross-site',
    },
    referrer: 'https://selfregistration.cowin.gov.in/',
    referrerPolicy: 'strict-origin-when-cross-origin',
    body: null,
    method: 'GET',
    mode: 'cors',
    credentials: 'include',
  })
    .then((res) => res.json())
    .then((response) => {
      const slotsFor25 = getSlotsFor25(response);

      if (slotsFor25.length) {
        const msg = slotsFor25
          .map((s) => `[${s.pin}] ${s.name}. Vaccines: ${s.vaccines}`)
          .join('\n');

        sendToSlack(`Found slots!\n${msg}`);

        return true;
      } else {
        return false;
      }
    })
    .catch((error) => {
      console.error(error);

      sendToSlack('Script errored!', error);

      return true;
    });
}

main();

Changing the URL to https://cdn-api.co-vin.in/api/v2/appointment/sessions/public/calendarByDistrict?district_id=${id}&date=${date} removes the need for a bearer token! This probably reduces the number of times someone would have to log in just to get that token

@yashshah1 Neat. Thanks!

@yashshah1 That URL has stale data every time.

@umanghome Somehow I haven't come across this issue. Let me recheck