Seedance 2.5 50 references: how many can you use on Sume?

Seedance 2.5 supports up to 50 references in BytePlus's documentation: 30 images, 10 videos and 10 audio clips. On Sume, a seedance-2.5 request accepts at most 12 input_references in total, counting images, videos and audio together.

ByteDance's launch post states the same 30 + 10 + 10 mix; the per-file limits below come from the ModelArk tutorial.

What are the per-file limits?

These are the vendor's stated limits. Check your files against them before you send a job to Sume.

What is Sume's cap and its shape?

Each entry is an object with type and a matching URL object, as in the video docs. The 12-entry cap is enforced by the API before the job is created.

curl -X POST https://api.sume.com/v1/videos \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "seedance-2.5",
    "prompt": "The woman from @image1 walks the street from @image2",
    "duration": 8,
    "resolution": "720p",
    "aspect_ratio": "16:9",
    "input_references": [
      {"type": "image_url", "image_url": {"url": "https://example.com/a.png"}},
      {"type": "image_url", "image_url": {"url": "https://example.com/b.png"}}
    ]
  }'

What should I do with more than 12 assets?

Split the work by shot. Generate each scene with the references it needs, then join the clips; see assemble long-form video with the Timeline API. Vendor guidance also favors fewer references: the prompt guide suggests 1 to 5 subjects.