Sume TTS Router: send sonic-3.6, sonic-latest or sonic-preview?

Send sonic-3.6 when you want a pinned, stable model, sonic-latest when you want to follow the newest stable one, and sonic-preview only for testing. In Sume's TTS Router, sonic-latest is an alias that resolves to sonic-3.6 today, and sonic-preview is a beta channel that can change without notice.

All five ids are Cartesia Sonic pass-through rows. They share the TTS 1.0 character price, and the router does not include other vendors in v1.

The five ids

From the Sume TTS Router docs.

Choosing in practice

Think about what happens when the vendor ships a new model.

• Pin sonic-3.6 for client work where the voice must not drift between months.
• Use sonic-latest for internal drafts, so you hear improvements without a code change.
• Keep sonic-preview out of anything customers hear, because its output and availability can change without notice.
• Keep older ids only if a script has been approved on them and must be reproduced.

Price and limits are the same across ids

Billing is the TTS 1.0 character book: $0.0475 per 1,000 characters (list 38 micro-dollars per character times 1.25), rounded up to the cent per job, with a 20,000-character cap. Read the numbers from GET /v1/tts-router/models rather than hard-coding them.

If a request to sonic-preview returns voice_model_mismatch, the voice is a pro clone. Send the same job to sonic-3.6 instead.

A migration habit

Store the model id with each finished job in your own database. When a provider retires an old Sonic version, you can then list which of your assets used it. Sume's metadata field on the request is kept with the job and is not forwarded to the provider, so it is a good place to write the id and your project name.