4K vertical 9:16 vs square 1:1 on Sume: which video models take which

If you need 4K vertical, use gemini-omni-flash-1.1, which takes 16:9 and 9:16 up to 4K. If you need a square 1:1 clip, kling-3 and seedance-2.5 take it, but their top resolution on Sume is 1080p, not 4K.

There is no row that does both on Sume today, so choose between a bigger frame and a different shape. The numbers below come from the catalog and docs in the repo.

The shapes each model accepts

Omni's envelope is 360p, 720p, 1080p and 4K, with 16:9 or 9:16 only. Auto uses the same envelope, because its default target is Omni, so an auto request for a 1:1 clip fails closed with a 400 unsupported_capability. Auto never silently routes to Seedance for it.

For a square clip, name kling-3 or seedance-2.5 in the request.

What a 4K vertical clip costs

Omni 4K is $0.30 a second at provider list, so $0.375 on Sume with the 1.25 multiple. A 10-second 4K clip is 10 x $0.375 = $3.75. The same clip at 1080p is 10 x $0.1875 = $1.875, which rounds up to $1.88.

A 4K clip costs exactly twice a 1080p clip, since $0.375 / $0.1875 = 2.

A vertical 4K request

Send aspect_ratio: 9:16 and resolution: 4K. If you are unsure about a prompt, draft at 720p first, since a draft costs a third of the final.

curl -X POST https://api.sume.com/v1/videos \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: vertical-4k-001" \
  -d '{"model":"gemini-omni-flash-1.1","prompt":"A barista pours latte art, slow push-in, warm morning light","duration":10,"resolution":"4K","aspect_ratio":"9:16"}'

If you need square and sharp

Generate square at 1080p with kling-3 or seedance-2.5, then upscale it with a tool of your choice if the placement needs more pixels. Check the Sume docs for the current video tools before you plan around one.

For a reel or a short, 9:16 at 1080p is the usual target, so most vertical work does not need 4K at all.

• Decide the shape first, because it limits the model.
• Draft at 720p, then render the final.
• Do not rely on sume/auto for 1:1, since it returns a 400.
• Read the catalog if you are unsure, as shown in the catalog filter script.