Pause-cut with Timeline alone: 14 slots from one source, no trims

You do not need a trim job per kept range. A Timeline render slot already has source_url, source_in, start and duration, and audio.parts[] slices the detached audio the same way, so one detach plus one render cuts a clip at every pause. For a render under a minute with 14 ranges that is $0.01 plus $0.10, against $0.39 if you trim 14 times first.

Instagram says its First Draft cuts the pauses and trims clips in one tap (read 2026-10-09). The API equivalent is one document that lists the kept ranges.

The document

Three of the 14 slots are shown. The slot start values are on the output timeline and must begin at 0 and increase; source_in is where each range begins inside the original. Each audio.parts entry cuts the same instants from the detached wav, so picture and voice stay locked. The lengths add up: 3.55 + 4.68 = 8.23, and 8.23 + 3.36 = 11.59, which is audio.duration_seconds.

{
  "audio": {
    "parts": [
      { "url": "https://media.sume.com/artifacts/artf_demo/spine.wav", "source_in": 0.55, "duration": 3.55 },
      { "url": "https://media.sume.com/artifacts/artf_demo/spine.wav", "source_in": 4.62, "duration": 4.68 },
      { "url": "https://media.sume.com/artifacts/artf_demo/spine.wav", "source_in": 9.84, "duration": 3.36 }
    ],
    "duration_seconds": 11.59
  },
  "video": [
    { "source_url": "https://media.sume.com/artifacts/artf_demo/talk.mp4", "source_in": 0.55, "start": 0,    "duration": 3.55 },
    { "source_url": "https://media.sume.com/artifacts/artf_demo/talk.mp4", "source_in": 4.62, "start": 3.55, "duration": 4.68 },
    { "source_url": "https://media.sume.com/artifacts/artf_demo/talk.mp4", "source_in": 9.84, "start": 8.23, "duration": 3.36 }
  ]
}

Cost against trimming first

Assumption: the stitched Reel stays under 60 seconds, so the render bills one minute at $0.10 (the rate is per ceil output minute). The trim route adds $0.02 per range on top of the same detach and render.

When you still want a trim job

• You need the cut as its own MP4, for example to hand to another tool.
• You want audio: "drop" or an output conform (width, height, fps), which only trim offers.
• You have more than 20 ranges: audio.parts stops at 20, so use two levels of concat.
• Past 12 slots the render chunks automatically (render.strategy: auto); single mode is refused above 12 slots.

Check before you pay

POST /v1/timeline-1.0/plan compiles the same document without creating a job and reports duration_seconds, segment_count and billable_minutes. It does not download media, so it cannot predict padded or looped short-source warnings.