Pause Ads: Add Support Pause-Ad In A Linear Format in VAST

[Nfrederiksen]

ℹ️ We currently have support for non-linear pause-ads in the Test AdServer.
However, some Ad Servers serve pause ads as linear ads as well. It's basically a normal VAST response but with a MediaFile URL pointing at an image rather than a video. It would be good for the Test AdServer to also be able to return a linear pause ad to emulate other Ad Server that do this.

I'm thinking we could add a query parameter on the existing pause-ad endpoint that specifies if it should be linear or non-linear.

Example pause ad VAST XML:

<VAST version="4.1" xsi:noNamespaceSchemaLocation="vast.xsd">
	<Ad id="83076144.139782267602176" sequence="1">
		<InLine>
			<AdSystem>FreeWheel</AdSystem>
			<AdTitle>Joakim Lundell: Ett Övergivet Barn</AdTitle>
			<Error>https://some.tracking.link/error</Error>
			<Impression id="FWi_83076144.0.1">https://some.tracking.link/impression/tracker.png</Impression>
			<Creatives>
				<Creative AdID="83076144" id="206907629">
					<Linear>
						<Duration>00:00:20</Duration>
						<TrackingEvents>
							<Tracking event="complete">https://some.tracking.link/complete</Tracking>
							<Tracking event="firstQuartile">https://some.tracking.link/1qtl</Tracking>
							<Tracking event="midpoint">https://some.tracking.link/2qtl</Tracking>
							<Tracking event="thirdQuartile">https://some.tracking.link/3qtl</Tracking>
						</TrackingEvents>
						<VideoClicks>
							<ClickThrough id="FWc_8">https://some.tracking.link/click?cr=https%3A//some.ad.link/site</ClickThrough>
						</VideoClicks>
						<MediaFiles>
							<MediaFile delivery="progressive" height="640" id="813784251" type="image/png" width="1135">
                                                                https://s1.fwmrm.net/my_pause_ad.png
                                                        </MediaFile>
						</MediaFiles>
					</Linear>
				</Creative>
			</Creatives>
		</InLine>
	</Ad>
</VAST>

NOTE: As seen in the example we have a duration. The duration in the linear pause-ad in often ignored in the players, but it doesn't hurt to have it as a query parameter.

[aleksUIX]

Update on this, since the spec caught up in the time it has been open.

IAB Tech Lab finalised the CTV Ad Portfolio guidance in July 2026, and the VAST 4.4 draft schema (vast_4.4.xsd, in the IAB VAST repo) now models Pause ads directly. The schema header says it explicitly:

• NonLinearAds support for CTV Pause, Screensaver, Overlay, Squeezeback, and In-Scene ads.
• MediaFiles and Duration under NonLinear.

and vastNonLinearAds_type carries:

VAST 4.4: NonLinearAds can represent CTV Ad Portfolio formats that appear alongside, over, or within content without mandating a dedicated content interruption, including Pause, Screensaver, Overlay, Squeezeback, and In-Scene ads.

So the thing this issue was working around now has a first-class answer. <NonLinear> gained a <MediaFiles> container and a <Duration>, which is what previously forced people to reach for a <Linear> with an image MediaFile. A 4.4 pause ad is a NonLinear with real media files, not a linear ad wearing a disguise.

That does not make the request here invalid. Ad servers in the wild absolutely do serve pause ads as linear with an image MediaFile, exactly as described, and they will keep doing so for years. A test ad server arguably wants to emulate the messy real-world shape precisely because it is non-conformant and players need to cope with it.

So the suggestion would be three modes rather than two on the pause-ad endpoint:

1. non-linear, current behaviour
2. linear-with-image, the compatibility shape this issue asks for
3. VAST 4.4 NonLinearAds, the CTV Ad Portfolio shape

Worth flagging that 4.4 is still a working-group draft and the schema annotation says so, so anything built against mode 3 should expect churn.

Happy to open a PR adding the linear pause-ad mode if that is still wanted, and can include a 4.4-shaped sample as a separate change if there is appetite for it.

[Nfrederiksen]

Yes absolutely. Feel free to contribute :) @aleksUIX
Open a PR, and tag me as reviewer.