title: Chromecast receiver window.deviceInfo.deviceId = serial number
body: <p>I have noticed that there is an object <code>window.deviceInfo</code> that contains the chromecast receiver serial number, where <code>deviceId</code> matches the serial number:</p>
  
  <pre><code>window.deviceInfo = {
      buildVersion: '16278',
      deviceId: '3923536d1ITU'
  }
  </code></pre>
  
  <p>This is not mentioned in the <a href="https://developers.google.com/cast/docs/reference/receiver/" rel="nofollow noreferrer">Chromecast Receiver API documentation</a>, and it has been previously stated that the serial number is not exposed.</p>
  
  <p><a href="https://stackoverflow.com/questions/21153049/how-do-i-get-a-serial-number-by-receiver-application-on-chromecast">How do I get a serial number by Receiver Application on Chromecast</a></p>
  
  <p>Can I rely on this value to as a unique identifier for the Chromecast receiver device, or are there plans to remove or change this value?</p>