# Client-side beaconing
<a name="ad-reporting-client-side-beaconing"></a>

With the client-side tracking `startTimeInSeconds` element, you can use MediaTailor to support beacons timing.

The following JSON response shows the main beacon types: impressions, start, quartiles, and completion.

**Note**  
The Interactive Advertising Bureau (IAB) Video Impression Measurement Guidelines state that an impression requires the ad content to load client-side and, at a minimum, begin time to render into the player. For more information, see [Digital Video Ad Serving Template (VAST)](https://www.iab.com/guidelines/vast/) on the IAB website.

```
{
  "avails": [
    {
      "ads": [
        {
          "adId": "8104385",
          "duration": "PT15.100000078S",
          "durationInSeconds": 15.1,
          "startTime": "PT17.817798612S",
          "startTimeInSeconds": 17.817,
          "trackingEvents": [
          {
              "beaconUrls": [
                "http://exampleadserver.com/tracking?event=impression"
              ],
              "duration": "PT15.100000078S",
              "durationInSeconds": 15.1,
              "eventId": "8104385",
              "eventType": "impression",
              "startTime": "PT17.817798612S",
              "startTimeInSeconds": 17.817
            },
            {
              "beaconUrls": [
                "http://exampleadserver.com/tracking?event=start"
              ],
              "duration": "PT0S",
              "durationInSeconds": 0.0,
              "eventId": "8104385",
              "eventType": "start",
              "startTime": "PT17.817798612S",
              "startTimeInSeconds": 17.817
            },
            {
              "beaconUrls": [
                "http://exampleadserver.com/tracking?event=firstQuartile"
              ],
              "duration": "PT0S",
              "durationInSeconds": 0.0,
              "eventId": "8104386",
              "eventType": "firstQuartile",
              "startTime": "PT21.592798631S",
              "startTimeInSeconds": 21.592
            },
             {
              "beaconUrls": [
                "http://exampleadserver.com/tracking?event=midpoint"
              ],
              "duration": "PT0S",
              "durationInSeconds": 0.0,
              "eventId": "8104387",
              "eventType": "midpoint",
              "startTime": "PT25.367798651S",
              "startTimeInSeconds": 25.367
            },
            {
              "beaconUrls": [
                "http://exampleadserver.com/tracking?event=thirdQuartile"
              ],
              "duration": "PT0S",
              "durationInSeconds": 0.0,
              "eventId": "8104388",
              "eventType": "thirdQuartile",
              "startTime": "PT29.14279867S",
              "startTimeInSeconds": 29.142
            },
            {
              "beaconUrls": [
                "http://exampleadserver.com/tracking?event=complete"
              ],
              "duration": "PT0S",
              "durationInSeconds": 0.0,
              "eventId": "8104390",
              "eventType": "complete",
              "startTime": "PT32.91779869S",
              "startTimeInSeconds": 32.917
            }
          ]
        }
      ],
      "availId": "8104385",
      "duration": "PT15.100000078S",
      "durationInSeconds": 15.1,
      "startTime": "PT17.817798612S",
      "startTimeInSeconds": 17.817
    }
  ]
}
```