Changelog

TTS speed controls & updated LLM models

TTS speak speed (Early Access)

You can now control the speaking rate of Deepgram TTS in the Voice Agent API using the agent.speak.provider.speed parameter. This parameter accepts a float value between 0.7 and 1.5, with 1.0 as the default.

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{
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  "type": "Settings",
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  "agent": {
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    "speak": {
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      "provider": {
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        "type": "deepgram",
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        "model": "aura-2-thalia-en",
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        "speed": 0.9
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      }
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    }
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  }
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}

This feature is in Early Access and is only available for Deepgram TTS. For more details, see TTS voice controls. To request access, contact your Account Executive or reach out to sales@deepgram.com.

Updated LLM models

New OpenAI models — Two new models are now available in the Standard pricing tier:

• gpt-5.4-nano
• gpt-5.4-mini

Gemini 2.0 Flash deprecated — The gemini-2.0-flash model is now deprecated. We recommend migrating to gemini-2.5-flash or a newer Gemini model. See the Google models table for alternatives.

For the full list of supported models and pricing tiers, see the Voice Agent LLM Models documentation.