Runway Veo 3.1 audio is 40 credits a second, 20 without; Sume's toggle

Runway's pricing page, read 2026-10-01, lists veo3.1 at 40 credits per second with audio and 20 without. At $0.01 per credit, a 5-second clip is $2.00 with sound and $1.00 silent. Sume does not list Veo. Its model with a priced audio switch is kling-3: $0.70 for 5 seconds with generate_audio off and $1.05 with it on.

How does the audio switch work on Sume?

generate_audio is an optional boolean on /v1/videos and defaults to the model's own capability. Only Kling has two list rates in the catalog. minimax-h3, minimax-h3-max and gemini-omni-flash-1.1 always produce native audio and take no toggle, and grok-imagine-video-1.5 is silent. See the video docs.

What does the toggle cost?

Reserved amounts at list x 1.25, rounded up to the cent.

How do I turn audio off?

Send generate_audio: false.

curl -X POST https://api.sume.com/v1/videos \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: silent-001" \
  -d '{
    "model": "kling-3",
    "prompt": "A glass of water on a windowsill, rain outside",
    "duration": 5,
    "resolution": "720p",
    "aspect_ratio": "16:9",
    "generate_audio": false
  }'