Providers

inworld-tts-2

The Inworld text-to-speech model inworld-tts-2, with every setting it accepts, the allowed value and the default.

The current generation. Steers variation with deliveryMode rather than a temperature, which makes delivery more predictable between renders. That Inworld setting is not settings.conversationConfig.deliveryMode. For model-steered laughs, sighs, and pauses, see expressive mode.

Reached through the LiveKit Inference gateway.

The two generations steer variation differently: the 1.5 models use temperature, and TTS-2 uses deliveryMode and ignores temperature. Setting the wrong one for your model is not an error; it is ignored.

Settings#

Every setting is optional. Leave one out and OnCore sends nothing for it, so the Default applies. If invalid is what the provider does with a value it does not accept.

Setting	Type	Allowed	Default	If invalid
`speakingRate`	number	above 0.5, up to 1.5	`1.0`	Refused, call fails
`deliveryMode`	string	STABLE, BALANCED, CREATIVE	`BALANCED`	Refused, call fails
`timestampType`	string	WORD or CHARACTER	no timestamps	Refused, call fails
`applyTextNormalization`	string	ON, OFF	`ON`	Refused, call fails

Overriding on a single call#

Return this from your assistant-request webhook to change these settings for one call only. The stored voice is left untouched, and the next call starts from it again.

json

{
  "data": {
    "overrides": {
      "voice": {
        "settings": {
          "speakingRate": 1,
          "deliveryMode": "BALANCED",
          "timestampType": "WORD",
          "applyTextNormalization": "ON"
        }
      }
    }
  }
}

Send only the keys you want to change: anything you leave out keeps the value the assistant already has. Add "id" beside "settings" to swap the whole voice for another one from your catalogue at the same time.

timestampType: Set to WORD or CHARACTER this turns on word-level or character-level timing for the synthesized audio. Left unset, no timing is produced. TIMESTAMP_TYPE_UNSPECIFIED is accepted and behaves the same as leaving it unset.

Next steps#

inworld-tts-1.5-max: the next Inworld model.
Providers introduction: per-call overrides, and how a wrong value behaves across providers.

Previoussonic-3 Nextinworld-tts-1.5-max