Kling 4.0 takes 15 reference assets; what Sume models accept

Kling 4.0 is described as taking up to 15 combined reference assets, but Kling 4.0 is not a callable id on Sume today, so the closest honest answer is a per-model table of what Sume does accept. The caps differ by model: wan-3.0 takes up to 10 images, 5 videos and 5 audio files; MiniMax H3 and H3 Max take up to 9 images, 3 videos and 3 audio files with at most 12 in total; Gemini Omni Flash 1.1 takes up to 10 images and 3 videos of at most 3 seconds each; the Seedance ids and everything else accepting references share a 12 item combined cap.

The Kling numbers are from kling.ai's Kling 4.0 vs 3.0 page, read on 2026-10-03: up to 10 images, up to 5 videos of 30 seconds combined, up to 7 subjects, 15 assets in all. Sume's limits come from the Video generation docs and the Video Router catalog.

Side by side

The table puts the vendor page next to what a Sume request will accept. Counts are of input_references entries on POST /v1/videos, or the reference_*_urls arrays on the Video Router route.

Two things in it matter most. First, Kling's 7 'subjects' have no direct equivalent: Sume has no subject object, only image, video and audio reference URLs, so a subject becomes one or more reference images. Second, kling-3 is the Kling model you can call and it accepts no references at all.

What a rejected request looks like

Going over a cap returns HTTP 400 with unsupported_capability, for example 'wan-3.0 accepts at most 5 video input_references', and the message names the field. Nothing is billed. For H3 and H3 Max, audio cannot be the only reference: the request needs an image or a video alongside it.

If you were planning a 15-asset Kling 4.0 request, the realistic port is to rank your assets. Keep the strongest ten for wan-3.0, or the strongest nine images plus three clips for minimax-h3-max, and put the rest into the prompt text.

How to choose

Pick by what the references are for. Product shots and a character sheet are image references: Wan or Omni (10) beat H3 (9). Motion or camera reference needs video: Wan allows five, H3 three, Omni three but only 3 seconds each. A voice or music reference needs audio: Wan, H3 or the Seedance ids.

Whichever you pick, call GET /v1/videos/models first and read supported_input_references so the request type matches the id. Billing is list times 1.25 for every Video Router model.