Holiday sale instrumental on Music Router: length in the prompt

Length goes in the words

To make a track for a holiday sale reel, send a prompt to POST /v1/music-router/generate. The duration and duration_seconds fields are rejected, so steer length in the prompt, for example "a 30-second track" or timed section lines such as [0:00-0:30] Intro: ....

With model omitted or set to sume/music-auto, Sume picks the engine (Lyria 3.5 today). The job result names the engine that ran under job.request.routed_model.

Request

curl -sS -X POST https://api.sume.com/v1/music-router/generate \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: sale-track-001" \
  -d '{
    "model": "sume/music-auto",
    "prompt": "Upbeat acoustic pop with sleigh bells, 110 BPM, a 30-second track. Bright intro, a lift at 0:12, resolve on a clean final beat. Instrumental, no vocals."
  }'

Fields

Put exclusions in the positive prompt, because negative_prompt is unsupported when non-empty. You can also pass an image_url (public HTTPS) as a mood reference.

Pricing and result

Every Music Router model charges the fixed Music price per audio generation; the catalog lists each model's provider list price for reference. Read the audio from result.artifacts[] where type is audio. Check the licence terms of any music you publish, and name vocals or lyrics only when you want them.