Gemini voice_key with store=false: 7 days; voice_ ids: 200, 1 year

With store=False, the Gemini API returns an encrypted voicekey_... value that your application keeps, and the docs list its retention as 7 days. A stored voice_... id keeps for 1 year, within 200 voices per project. Sume's TTS request accepts only Sume voice ids.

What are the two Gemini storage modes?

Stateful (store=True, the default) keeps the verified profile in your project and returns a persistent voice_id. Stateless (store=False) is for workloads that need zero server-side persistence; your app stores the key and passes it in synthesis requests. Read 2026-10-01.

What voice ids does Sume accept?

A TTS voice UUID (8-4-4-4-12 hex) or a Voices library id (voi_ plus 32 hex), up to 128 characters, "not a voice name from another TTS ecosystem". A Gemini voice_ or voicekey_ value is the wrong shape and fails with 400 public_reason=invalid_voice_id before a job is queued or credits are reserved. See the API reference.

Do Sume voices expire after a few days?

The sources do not state a lifetime for Sume voice ids, so do not assume one. A bad or missing id fails fast, before any credit reservation, so you can check an id with a small request. TTS 1.0 has no engine picker, and a request holds up to 20,000 characters.

How does the 200-voice limit compare with Sume?

The Gemini limit is on stored voices per project. For the avatar-based selector on Sume, see Gemini TTS 200 voices and Sume's avatar voice selector.