Video 1.0 reference_audio_urls: why audio alone is rejected

On POST /v1/video-1.0/generate, reference_audio_urls needs at least one reference image or reference video in the same request, so an audio-only reference set is not a valid request. The field takes 1 to 3 audio URLs.

What are the reference limits?

The Video 1.0 request table gives a count for each reference field. All URLs must be public HTTPS.

How do I send audio with a reference image?

Add the audio URL next to an image reference. The example uses placeholder URLs.

curl -X POST https://api.sume.com/v1/video-1.0/generate \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: v1-audio-001" \
  -d '{"prompt":"The singer performs to camera","reference_image_urls":["https://example.com/singer.png"],"reference_audio_urls":["https://example.com/song.mp3"]}'

Is this the same on /v1/videos?

There, supported_input_references per model says which types (image_url, video_url, audio_url) a model accepts. Audio and video references are honored by the Seedance 2.x models, Wan 3.0, MiniMax H3 and MiniMax H3 Max; Gemini Omni Flash 1.1 accepts video references but not audio.

Where can I read the full field list?

The Video 1.0 docs list every field, and the video generation docs cover the newer route.

What does the reference video field allow?

reference_video_urls takes 1 to 3 video URLs and reference_image_urls takes 1 to 9 images, so a request can combine a few clips with images and then add audio.

On the Video Router side, gemini-omni-flash-1.1 takes up to 10 reference images and up to 3 reference videos of at most 3 seconds each, and has no reference_audio_urls. Read the capabilities for the model you pin.