Does Lyria 3.5 on the paid Gemini API train on my prompts?

No for the paid tier, according to the Gemini API pricing page as read on 2026-10-04: its row for whether data is used to improve Google's products shows Yes on the free tier and No on the paid tier for the Lyria models. Lyria 3.5 is listed with no free tier at all, so a lyria-3.5 call is always a paid-tier call.

That is Google's statement about Google's API. This post covers what that row says, which Lyria models it applies to, and what to check when you reach Lyria through another provider.

What the pricing page shows

The rows below are taken from the pricing page, not from the music docs.

Reading the row correctly

The row is about Google using prompts and outputs to improve its products. It does not say who owns the generated song or whether the audio can be used commercially; those questions are separate and the page does not answer them.

The Gemini music docs add that generated audio carries a SynthID watermark. That is a provenance mark, not a data-use setting.

• Free tier and paid tier are different terms. Check which one your key is on.
• The lyria-3-clip-preview and lyria-3-pro-preview models sit in a legacy family on the pricing page.
• lyria-3.5 is the only one with no free tier.

Using Lyria 3.5 through Sume

Sume's Music Router can route to lyria-3.5, lyria-3-pro or the default sume/music-auto. The price is a fixed $0.125 per generation, and job.request.routed_model tells you which engine ran. Sume's own data-handling terms are what apply to your Sume account, so read them and the Sume docs for the router itself rather than assuming Google's paid-tier row transfers.

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-data-use-001" \
  -d '{
    "model": "sume/music-auto",
    "prompt": "Warm lo-fi hip hop, 84 BPM, C minor. Dusty Rhodes chords, brushed drums. A 30-second track. Instrumental, no vocals."
  }'

Quick checklist

• Confirm the tier your Gemini key is on before sending anything sensitive.
• Keep brand-confidential lyrics out of any free-tier prompt.
• Record the engine that ran: routed_model on a Sume job.
• Treat ownership and licensing as a separate question from data use.