Rough cut from a script by API: one scene per Timeline slot

To turn a script into a rough cut with Sume, put the narration on the audio spine (audio.url, up to 1800 s) and give each scene one video[] slot whose start and duration line up with when that scene is spoken. The Timeline assembles the slots you declare; the docs describe no route that splits a script or picks visuals.

Descript describes Quick Design as one that "Splits your content into logical moments so visuals change over time instead of staying on one continuous shot". The Sume route is from the Timeline 1.0 docs, read 2026-09-30.

How do scene times line up with the voiceover?

Decide scene boundaries in your own code, for example from the sentence timings of the narration. Each slot's start is on the spine; video[0].start must be 0 and later starts must increase. If the narration is several files, POST /v1/timeline-1.0/audio with operation: "concat" returns segments[] (index, start, duration_seconds), the offsets to re-base video[].start against.

curl -X POST https://api.sume.com/v1/timeline-1.0/render \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: script-rough-cut-001" \
  -d '{
    "audio": { "url": "https://media.sume.com/artifacts/artf_demo/narration.wav", "duration_seconds": 20 },
    "video": [
      { "source_url": "https://media.sume.com/artifacts/artf_demo/scene1.mp4", "start": 0, "duration": 9 },
      { "source_url": "https://media.sume.com/artifacts/artf_demo/scene2.png", "start": 9, "duration": 11,
        "transition": { "type": "dissolve", "duration": 0.5 } }
    ]
  }'

Can a slot be a still?

Yes: source_url may be a Sume-hosted still, which is a static hold. A motion field on a still is accepted and ignored, with a motion_ignored warning. fit is cover (default), contain, stretch or blur.

What are the limits?

Descript says Quick Design is for single-speaker videos and "Can only be used on single-scene projects". Sume's limits are numeric: 1 to 200 slots, 1 to 1800 s. Check length and cost first with the unbilled /plan.