Kling 4.0 keyframes at 0, 6, 12, 20, 28 s: a 30-second ad on Sume

Kling 4.0 accepts up to 10 keyframe images in one generation, and its multiple keyframes guide suggests placing them near 0, 6, 12, 20, and 28 seconds for a product ad. On Sume you can approximate that plan with chained clips: four first-and-last-frame jobs covering 28 seconds, plus a short end card.

From five keyframes to four clips

Kling's comparison page says Kling 3.0 supported start and end frames only. That start-and-end pairing is what Sume's frame_images field expresses, so the chained plan below uses one pair per clip.

The segment plan

Clip N starts on keyframe N and ends on keyframe N+1, so the joins land on shared pictures. The final two seconds, 28 to 30, are below the 4 second minimum the seedance-2 row lists, so cover them with an end card rather than a fifth clip.

One clip as a request

The seedance-2 example row in the Sume docs lists first_frame and last_frame in supported_frame_images and durations of 4 to 15 seconds, which covers the clip lengths above. Read the same fields for any other model first. The request for clip 2 looks like this.

{
  "model": "seedance-2",
  "prompt": "Product on a clean desk, slow push-in, soft daylight",
  "frame_images": [
    {
      "type": "image_url",
      "image_url": {"url": "https://example.com/keyframe-2.png"},
      "frame_type": "first_frame"
    },
    {
      "type": "image_url",
      "image_url": {"url": "https://example.com/keyframe-3.png"},
      "frame_type": "last_frame"
    }
  ],
  "duration": 6,
  "resolution": "1080p",
  "aspect_ratio": "16:9"
}

Making the joins less visible

Joins show when lighting, framing, or subject position change at a cut. Because each clip ends on the same keyframe the next one starts on, position and framing match by construction. The remaining risk is motion: a camera that speeds up at the end of one clip and starts slow in the next.

Write each prompt so motion eases at both ends, for example a slow push-in that settles. A dissolve of a few frames also helps, and a timeline can apply one. Review the joins at full size on a large screen, not in a thumbnail.

• Use the same lighting description in all four prompts.
• Ask for motion that settles at the end of each clip.
• Keep keyframes in the same aspect ratio.
• Review every join at full size.

What you give up

A chain is not a single generation. Motion will not be continuous across the joins the way Kling's one-pass keyframe sequence aims to be, and a missing seed means a rerun gives a new take. Keep the keyframes visually consistent, and plan cuts rather than hidden transitions. Sume documents input_references for style guidance if you want the same look across all four clips. The video docs show both fields.