Music Router: lyria-3-pro costs the same $0.125 as lyria-3.5

The Sume Music Router lists three routable ids: sume/music-auto (the default), lyria-3.5 and lyria-3-pro. The docs say every Music Router model charges the fixed Music price per audio generation, which is $0.125 on the Music 1.0 page. So choosing the Pro id does not change what Sume charges per accepted generation; the catalog lists each provider's list price only for reference.

Auto versus pinned

With model omitted or set to sume/music-auto, Sume picks the engine (Lyria 3.5 today). To pass through to one engine, pin an explicit id from GET /v1/music-router/models. The job echoes the id you asked for in job.model, while job.request.routed_model names the engine that ran.

What stays unchanged between ids

The request body is the Music 1.0 body plus the optional model: same prompt limit, same ban on duration and non-empty negative_prompt, same optional image_url, same modes. An unknown id fails with 400 model_not_found and a catalog_url, so a typo is caught before billing.

Music 1.0 routes keep working and keep job.model = sume/music-1.0, but every request resolves through the router now. For a new integration the docs recommend POST /v1/music-router/generate.

Request

Pin Lyria 3 Pro for one request like this.

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: music-router-pro-001" \
  -d '{
    "model": "lyria-3-pro",
    "prompt": "A 45-second cinematic build, 70 BPM, D minor. Strings and low piano. Instrumental, no vocals."
  }'

How to compare engines

Because the price is identical, compare by ear. Run the same brief once on lyria-3.5 and once on lyria-3-pro: 2 x $0.125 = $0.25 for the pair. Keep the winning id in your config. If you never pin, you follow whatever Sume routes to, which today is Lyria 3.5.

Reading the catalog

Call GET /v1/music-router/models before you hard-code an id. The catalog is the source of truth for which ids are routable, and GET /v1/music-router/models/{model_id} returns one entry. Ids can change over time, which is why the router returns catalog_url on an unknown-id error.

• Default: sume/music-auto.
• Provider list prices appear in the catalog for reference only.
• Sume charges the fixed Music price per audio generation on every router model.