Music from a thumbnail: image_url on Sume's music router

Can you generate music from an image? Yes, with Sume's Music Router: send a prompt and one optional image_url. The Music 1.0 docs call this visual conditioning and show a cinematic ambient underscore matched to the mood of a reference still. The image must be a public HTTPS URL.

An image does not replace the prompt. The prompt is still required (1 to 5000 characters), and the docs say to write exclusions and length into it.

The request

image_url is optional and can be null to clear. Send null only when you reuse a request object on a client and want the image gone.

curl -X POST https://api.sume.com/v1/music-router/generate \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: thumb-music-001" \
  -d '{
    "model": "sume/music-auto",
    "prompt": "Cinematic ambient underscore matching the mood of the reference still. Instrumental, no vocals. A 30-second track.",
    "image_url": "https://example.com/moodboard.png"
  }'

Image conditioning, rule by rule

Where to get the still

For a scene-matched score, the Music 1.0 docs suggest passing the accepted scene still as image_url when it fits, and varying genre family, tempo (at least 12 BPM apart) and lead instrument between contrasting scenes. If you want one consistent score, keep those fixed.

What not to expect

The docs describe image input as conditioning, not a guarantee that the audio will map to what is in the picture. Listen to the result and rewrite the brief, not the image, first.