Yoga studio class promo clip: Kling 3 for 8 seconds, audio or silent

An 8-second yoga class promo from a studio photo is a kling-3 job at $1.12 silent or $1.68 with audio on Sume, vertical 9:16 at 720p or 1080p. If you will add a music bed on a timeline, take the silent price and save $0.56 per clip (Video Router, read 2026-10-05).

What do I send?

Use the studio photo as the first frame. Describe slow, calm movement and light, and leave the class times for a caption.

curl -X POST https://api.sume.com/v1/videos \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"kling-3","prompt":"Morning light across the studio floor, a mat unrolls, slow calm camera drift","duration":8,"resolution":"1080p","aspect_ratio":"9:16","frame_images":[{"type":"image_url","image_url":{"url":"https://example.com/studio.jpg"},"frame_type":"first_frame"}],"generate_audio":false}'

What does a month of promos cost?

A studio with four class types and a clip each week makes about sixteen clips a month.

How do I poll and download the result?

A submit returns 202 with id, polling_url, status and model. Poll GET /v1/videos/{id} until status is completed (the other terminal values are failed and cancelled), then download from GET /v1/videos/{id}/content?index=0 with the same bearer key. Kling 3 accepts 4 to 15 seconds, so 8 seconds is mid-range.

curl https://api.sume.com/v1/videos/JOB_ID -H "Authorization: Bearer $SUME_API_KEY"
curl -L "https://api.sume.com/v1/videos/JOB_ID/content?index=0" \
  -H "Authorization: Bearer $SUME_API_KEY" --output clip.mp4

How do I add music?

Generate a track with the music tool and lay it under the clip on a timeline. For the audio-or-silent decision on Kling in general, see Kling 3 native audio cost.