VAST tracking events / Linear
interactiveStart VAST tracking event
Short answer: Fires when a SIMID creative takes control. VAST 4.1+, expected on 4.2+ linear SIMID. Introduced in VAST 4.1.
When it fires
The interactive layer started. Linear SIMID tags on VAST 4.2+ should include it so measurement sees the handshake, not only start. vastlint flags the missing event as info. It does not run createSession; that is tester or studio work.
The SIMID layer took control
interactiveStart fires when a SIMID creative starts its interactive session. VAST 4.1 added the event. On a linear SIMID unit the media start beacon can fire and the interactive layer can still fail to start. interactiveStart is how you see that second step. start alone cannot show it.
vastlint notes a missing interactiveStart on linear SIMID as information. It does not open a SIMID session. A clean document can still fail at runtime, and that failure shows up in the tester, not as a schema error. A 3.0 document has no interactiveStart. SIMID itself is not a 3.0 feature.
start without interactiveStart
The media can play while the SIMID layer fails to create a session. start and the quartiles fire, and interactiveStart does not, so a KPI that only watches start treats a failed interactive layer as a completed play. The interactive file, the verification node, and the SIMID handshake are the places to look, in the tester, because the document can be structurally valid and still fail at runtime.
interactiveStart on a linear creative that has no InteractiveCreativeFile will not fire, because there is no session to start. vastlint's note is for SIMID creatives that omitted the event. Adding the event to an ordinary mp4 does not create an interactive session, and the URL stays quiet.
When the column stays empty
interactiveStart is absent from VAST 2.0 and from 3.0. A player that only implements those versions will not request it. The version table on this page is the set that includes it.
Each wrapper hop may include its own interactiveStart URL. The player requests every one of them when the event happens, so a chain of four hops produces four calls for one playback. An http URL on an https page is dropped by the browser before the ad server sees a miss. The event name can be right and the scheme can still zero the column.
Where it is valid
| 2.0 | 3.0 | 4.0 | 4.1+ |
|---|---|---|---|
| No | No | No | 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
Put it in a Linear TrackingEvents block. It is not valid on the other creative types, and a player does not fire a tracker in the wrong container.
<Linear>
<TrackingEvents>
<Tracking event="interactiveStart">
<![CDATA[https://track.example.com/interactiveStart]]>
</Tracking>
</TrackingEvents>
</Linear>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
- SIMID-1.0-simid-interactive-start: Linear SIMID creative on VAST 4.2+ should include an interactiveStart tracking event
- VAST-4.1-tracking-event-value: Tracking event attribute not in the valid set for this VAST version
Related events
- start: Fires when linear playback actually begins, first frame rendered.
- creativeView: Fires when the creative is first displayed. Primary signal for NonLinear and companions.
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.