Wan 3.0 duration 35 for a Short: max is 30 s, so split it: $8.75

A Wan 3.0 job on Sume takes between 2 and 30 whole seconds. The pricing code states the rule when you try 35: the duration is outside the billable range 2-30. For a 35-second vertical Short, split it into two jobs, 30 s and 5 s, and join them. At 1080p ($0.25 a second) that is $7.50 + $1.25 = $8.75, plus $0.10 for the Timeline minute.

35 seconds sits well inside the Shorts limit of 3 minutes (YouTube Help, read 2026-10-09); the constraint is the model, not the platform.

Where the split should fall

Because the rate is linear, any split costs the same. You pick the split for the story; just keep both pieces at 2 seconds or more.

Duration limits for the vertical models

Check supported_durations in GET /v1/videos/models. These are the ceilings from the Sume docs and catalog on 2026-10-09:

curl -X POST https://api.sume.com/v1/videos \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"wan-3.0","prompt":"Scene 1 of 3: ...",
   "aspect_ratio":"9:16","resolution":"1080p","duration":30}'

Gotchas

• Send duration as an integer number of seconds; the catalog lists whole seconds only.
• Do not request 35 and expect a clamp. Split the plan before you spend money on a batch.
• When you join the two clips, the second job needs a first frame, if you want continuity: take the last frame of job 1 and send it as frame_images first_frame to job 2.
• Timeline bills per output minute rounded up, so 35 seconds is one minute.