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

# Speechify

> Use the Speechify text-to-speech plugin in a Zero Runtime pipeline.

Speechify is a **text-to-speech** plugin. It turns the LLM's reply into audio the caller
hears using Speechify's SIMBA model family.

## Setup

Set your Speechify API key in the worker environment. Generate a key from the [Speechify console](https://console.sws.speechify.com/):

```bash theme={null}
export SPEECHIFY_API_KEY=<key>
```

## Usage

Import the plugin and pass it to the pipeline's `tts` slot.

<CodeGroup>
  ```python Python theme={null}
  from zeroruntime.plugins import SpeechifyTTS

  tts = SpeechifyTTS()

  # Pipeline(tts=tts, ...)
  ```

  ```typescript Node JS theme={null}
  import { SpeechifyTTS } from '@zeroruntime/js-sdk/plugins';

  const tts = SpeechifyTTS();

  // Pipeline({ tts, ... })
  ```
</CodeGroup>

## Parameters

| Parameter | Type | Default | Description |
| - | - | - | - |
| `api_key` | `str \| None` | `None` | Speechify API key. Falls back to the `SPEECHIFY_API_KEY` environment variable when unset. |
| `voice_id` | `str` | `"kristy"` | Speechify voice identifier. Browse the full catalogue at the Speechify voice library. |
| `model` | `str` | `"simba-english"` | SIMBA model variant. `"simba-english"` is the flagship English model with the highest quality, lowest streaming latency, and full SSML support. `"simba-multilingual"` adds cross-language support. `"simba-base"` and `"simba-turbo"` are deprecated. |
| `sample_rate` | `int` | `24000` | Output audio sample rate in Hz. |

Spoken replies support interruptions. When the caller talks over the agent, the runtime
stops the audio and listens again. See the [plugins overview](/runtime-sdk/plugins/overview) for how TTS fits into the rest of the pipeline.


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