Does each Shorts series episode need to stand alone?
Each Shorts episode may be the first one a viewer sees. Add a recap overlay with Sume trim, compose and Timeline 1.0 for about $0.15.
Plan on it: an episode in a YouTube Shorts series can be the first thing a viewer sees. YouTube says viewers who find an episode in their feed get a watch-series button that opens the series feed, so a new viewer may start on episode 6. A short context plate over the first seconds, such as the show name and a one-line setup, fixes that, and in Sume it takes three small jobs and about 15 cents.
What YouTube says about how people arrive
YouTube's help page for Shorts series describes the feed behaviour and the swipe between the previous and next episode (YouTube Help). On September 23, 2026, YouTube said the feature rolls out on web, mobile and TV, with sequential playback (YouTube Blog). Neither page tells you how to write an opening. That part is an editing choice: assume a viewer has not seen the earlier episodes.
What goes on the plate
Do not bake a long recap into every episode. Put one line over the opening scene, the same place each time. Good plates answer who, where and what is at stake in under ten words, for example the show name, a place and the stakes. Avoid episode numbers inside the picture: YouTube numbers episodes by publish date, so a number you burn in can disagree with the one shown beside the video.
The three jobs
Do it in three steps. Trim the first 3 seconds of the episode with POST /v1/video-trim ($0.02). Overlay your plate image, a PNG you import, on that clip with POST /v1/timeline-1.0/compose using operation: overlay, position: top and a width_ratio such as 0.8 ($0.02). Then render with Timeline 1.0: the composed 3 seconds first, then the original episode with source_in: 3, over the episode's own audio, which you detach once for $0.01.
Compose keeps the still on screen for the whole clip it is given, which is why the trim comes first. The Timeline 1.0 spine duration should equal the episode's original length.
| Step | Endpoint | Sume rate |
|---|---|---|
| Trim first 3 s | POST /v1/video-trim | $0.02 per job |
| Overlay plate | POST /v1/timeline-1.0/compose | $0.02 flat per job |
| Detach episode audio | POST /v1/audio-detach | $0.01 per job |
| Assemble | POST /v1/timeline-1.0/render | $0.10 per ceil(output minute) |
| Total, up to 60 s | - | $0.15 |
Reuse it across the season
Make the plate PNG once and reuse it, and run the same three jobs across the season with a stable Idempotency-Key per episode. If an episode is already near 180 seconds, remember that the plate is an overlay, not an extra segment, so the length does not change.
Sources
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