> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://developers.deepgram.com/changelog/2026/3/26/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://developers.deepgram.com/_mcp/server.

## 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.

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

This feature is in Early Access and is only available for Deepgram TTS. For more details, see [TTS voice controls](/docs/tts-voice-controls#parameters). 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](/docs/voice-agent-llm-models#google) for alternatives.

For the full list of supported models and pricing tiers, see the [Voice Agent LLM Models documentation](/docs/voice-agent-llm-models).