Lyria 3 Pro or Lyria 3.5: which model id do I send?

On Sume, send lyria-3.5 if you want Lyria 3.5, lyria-3-pro if you want Lyria 3 Pro, or leave model out (or use sume/music-auto) to let Sume choose. Auto resolves to Lyria 3.5 today, and the catalog says it may move without notice, so a pinned id is the only way to keep a fixed engine.

Sume's ids are from the Music Router docs. Google lists the models on its Gemini API pricing page. Read 2026-09-29. This post does not rank the two; Sume's docs make no quality claim about either.

What ids does the Music Router accept?

What does Google list for each?

Google's pricing page lists Lyria 3.5 and Lyria 3 Pro Preview as full-song models at $0.08 per song each, paid tier only. Its Lyria developer page documents the lyria-3.5 id and does not show a Lyria 3 Pro id, so use Sume's catalog, not Google's page, to confirm the Pro id on Sume.

How do I pin a model and check which one ran?

Set model. The job echoes the id you requested in job.model, and job.request.routed_model names the catalog engine that ran.

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: pro-pin-001" \
  -d '{
    "model": "lyria-3-pro",
    "prompt": "Slow cinematic strings, 60 BPM, D minor. A 45-second track. Instrumental, no vocals."
  }'

Does the model change the request or the price?

No. Every Music Router model takes the same body (prompt, optional image_url, no duration, no non-empty negative_prompt) and charges the same fixed music price per generation. The catalog at GET /v1/music-router/models lists each model's capabilities and its list price for reference, so you can compare the rows yourself before you pin one.