ytdlr.js

(() => {
  let fetch
  let host = 'https://www.youtube.com'
  let path = '/youtubei/v1/player?key=AIzaSyAO_FJ2SlqU8Q4STEHLGCilw_Y9_11qcW8'
  if (typeof window === 'undefined') {
    fetch = (url, opts) => {
      url = new URL(url)
      opts = { ...opts, host, path }
      return new Promise((resolve, reject) => {
        let req = require(url.protocol.slice(0, -1)).request(opts, (res, data = '') => {
          res.on('data', chunk => { data += chunk })
          res.on('end', () => resolve(JSON.parse(data)))
        })
        if (opts.body) req.write(opts.body)
        req.on('error', e => reject(e))
        req.end()
      })
    }
    module.exports = ytdlr
  } else {
    fetch = (url, opts) => window.fetch(url, opts).then(j => j.json())
    window.ytdlr = (id, lang) => ytdlr(id || new URLSearchParams(window.location.search).get('v'), lang)
  }
  async function ytdlr (id, lang = 'en-US') {
    lang = lang.split('-')
    let body = await fetch(host + path, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({
        context: {
          client: { hl: lang[0], gl: lang[1], clientName: '3', clientVersion: '16.50', clientScreen: 'EMBED' },
          thirdParty: { embedUrl: host }
        },
        videoId: id
      })
    })
    if (body.playabilityStatus.status !== 'OK') throw Error(body.playabilityStatus.reason)

    return {
      details: body.videoDetails,
      formats: [...body.streamingData.formats || [], ...body.streamingData.adaptiveFormats || []]
    }
  }
})()