45 seconds on Wan 3.0: a 30 s and a 15 s job, $11.25 at 1080p

A 45-second video is two Wan 3.0 jobs, 30 seconds plus 15 seconds, and costs $11.25 at 1080p or $5.625 at 720p on Sume. One Wan 3.0 job tops out at 30 seconds, so anything longer is chained (read 2026-10-09).

Three ways to split 45 seconds

Because Wan 3.0 is flat per second, every split of 45 seconds costs the same. The choice is about how many seams you want to hide: two jobs means one seam.

Chain with the last frame

Extract the last frame of job one with POST /v1/video-frames (the clip must be hosted on media.sume.com), then pass that still as first_frame of job two. The frame list entries come back as durable image URLs.

# job 2: continue from the last frame of job 1 (15 s, 1080p)
curl -X POST https://api.sume.com/v1/videos \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Idempotency-Key: long-film-part-2" \
  -d '{
    "model": "wan-3.0",
    "prompt": "Continue the same shot: the boat clears the cliffs into open water",
    "duration": 15,
    "resolution": "1080p",
    "frame_images": [{
      "type": "image_url",
      "image_url": {"url": "<LAST_FRAME_URL_FROM_JOB_1>"},
      "frame_type": "first_frame"
    }]
  }'

Cost of the seam

There is no extra fee for the seam. A single imaginary 45-second job at 1080p would cost 45 x $0.25 = $11.25, which equals the two-job total of $11.25. The seam costs only the extra extraction call, which the docs say is billed by its own Modal compute.

A 60-second film is two 30-second jobs: $15.00 at 1080p or $7.50 at 720p. A 90-second film is three: $22.50 at 1080p.

Draft the whole film at 480p first: a 45-second draft in two jobs costs $2.8125, about 25 percent of the 1080p price.

Seams and limits

• Job two does not know job one. Repeat the subject, light and camera in the prompt, and add a reference image for the character.
• Put the cut on a natural beat; a hard cut hides a small continuity drift better than a slow dissolve.
• Keep each job's idempotency key unique per part, so a retry of part two never creates a duplicate.
• If part one fails, you pay nothing for it where the reservation is released, so chain only after it completes.