VAST tracking events / Linear
VAST start tracking event
Short answer: Fires when linear playback actually begins, first frame rendered.
When it fires
Linear playback has begun. Compare this count against impressions (fetched but not played) and against firstQuartile (played but stalled). It is the number to reconcile quartiles against, not the billable event in most contracts.
Where it is valid
| 2.0 | 3.0 | 4.0 | 4.1+ |
|---|---|---|---|
| Yes | Yes | Yes | Yes |
Legal containers: Linear. An event in the wrong container is not a player error. It is a URL nobody calls.
Using it in a tag
<TrackingEvents>
<Tracking event="start">
<![CDATA[https://track.example.com/start]]>
</Tracking>
</TrackingEvents>VAST XML fragment only. This excerpt belongs inside a complete VAST document, so standalone validation will fail until it is wrapped in a full <VAST>response.
Related vastlint rules
- VAST-2.0-linear-tracking-quartiles: <Linear> has no standard quartile tracking events — measurement system receives no signal
- VAST-4.1-tracking-event-value: Tracking event attribute not in the valid set for this VAST version
Related events
- creativeView: Fires when the creative is first displayed. Primary signal for NonLinear and companions.
- firstQuartile: Fires when linear playback reaches 25 percent of Duration.
- loaded: Fires when the player has the media file and is ready. VAST 4.1+.
Check the XML, then confirm the beacons fire
Validate the event names and containers on the document. Test a live URL when the XML is clean and reporting is still empty.