> ## Documentation Index
> Fetch the complete documentation index at: https://docs.threetone.in/llms.txt
> Use this file to discover all available pages before exploring further.

# Speed

> Prepare speech-rate options using the selected model's schema and a consistent listening script.

Speech rate should make the response easy to follow, especially when it contains dates, names, or instructions. Prepare a moderate setting and a repeatable listening script before experimenting with faster delivery.

<Note>
  Speed is model-specific configuration under `conversation_config.tts.options`. There is no universal top-level TTS speed field. Voice publication remains unavailable, and the dashboard voice preview does not save these settings.
</Note>

## Use the model's options

Read the selected model through [Get available AI model](/api-reference/agents-platform/get-available-ai-model). Match `options.schema_id` and the option names to that model's parameter schema.

Examples of current authoring contracts:

| Model | Options schema | Rate setting |
| - | - | - |
| `cartesia/sonic-3.6` | `cartesia_sonic_tts_options_v1` | `speed`: `slow`, `normal`, `fast`, or a number from 0.6 to 1.5. |
| `sarvam/bulbul:v3` | `sarvam_bulbul_v3_tts_options_v1` | `pace`: a number from 0.5 to 2.0. |

These identifiers describe accepted authoring shapes, not guaranteed catalog availability or working speech execution. Check the current catalog before using them. Do not transfer an option object from one model to another.

## Prepare a rate comparison

<Steps>
  <Step title="Choose one short script">
    Include an ordinary explanation, a number, and a name. Use the same text and voice for each comparison so the rate is the only planned difference.
  </Step>

  <Step title="Change one option">
    Preserve the model and voice IDs, then set the supported rate option in a [server draft](/agents-platform/deploy/versioning). Keep unrelated options unchanged.
  </Step>

  <Step title="Read the draft back">
    Check the schema ID, option name, and value. Record the desired outcome, such as clearer numbers or shorter pauses, for a later listening review when the speech path is available.
  </Step>
</Steps>

## Frequently asked questions

<AccordionGroup>
  <Accordion title="Does a faster rate reduce model response latency?" id="faq-speed-latency">
    Speech rate describes the intended delivery of generated speech. It does not promise a faster model response or lower end-to-end latency.
  </Accordion>

  <Accordion title="Why is my speed value rejected?" id="faq-speed-value">
    Check that the option name, schema ID, and numeric range belong to the selected model. Some models use pace, others speed, and not every model exposes the same control.
  </Accordion>
</AccordionGroup>


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.