> ## Documentation Index
> Fetch the complete documentation index at: https://daily-docs-pr-5356.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Speechify Text-to-Speech

> HTTP-based TTS with SpeechifyHttpTTSService: word-level timestamps via Server-Sent Events using simba-3.2 and simba-3.0 models.

## Overview

`SpeechifyHttpTTSService` streams PCM audio and word-level speech marks over Server-Sent Events from Speechify's `/v1/audio/stream/with-timestamps` endpoint. Audio and timestamps arrive together, enabling word-by-word conversation context attribution and accurate interruption handling.

<CardGroup cols={2}>
  <Card title="Speechify API Reference" icon="code" href="https://reference-server.pipecat.ai/en/latest/api/pipecat.services.speechify.tts.html">
    Pipecat's API methods for Speechify TTS integration
  </Card>

  <Card title="Example Implementation" icon="play" href="https://github.com/pipecat-ai/pipecat/blob/main/examples/voice/voice-speechify-http.py">
    Complete example with Deepgram STT and OpenAI LLM
  </Card>

  <Card title="Update Settings Example" icon="play" href="https://github.com/pipecat-ai/pipecat/blob/main/examples/update-settings/tts/tts-speechify-http.py">
    Changing voice mid-conversation with TTSUpdateSettingsFrame
  </Card>
</CardGroup>

## Installation

```bash theme={null}
uv add "pipecat-ai[speechify]"
```

## Prerequisites

Before using `SpeechifyHttpTTSService`, you need:

1. **Speechify Account**: Sign up for API access
2. **API Key**: Obtain an API key for authentication
3. **Voice Selection**: Choose from available Speechify voice models

### Required Environment Variables

* `SPEECHIFY_API_KEY`: Your Speechify API key for authentication
* `SPEECHIFY_VOICE_ID` (optional): Default voice identifier to use

## Configuration

<ParamField path="api_key" type="str" required>
  Speechify API key for authentication.
</ParamField>

<ParamField path="aiohttp_session" type="aiohttp.ClientSession" required>
  An aiohttp session for HTTP requests. You must create and manage this
  yourself.
</ParamField>

<ParamField path="base_url" type="str" default="https://api.speechify.ai">
  Base URL for the Speechify API.
</ParamField>

<ParamField path="sample_rate" type="int" default="None">
  Audio sample rate in Hz. When `None`, uses the pipeline's configured sample
  rate. Must be one of: 8000, 16000, 22050, 24000, 44100, 48000. If the
  requested rate is not supported, the service synthesizes at 24000 Hz and the
  output transport will resample.
</ParamField>

<ParamField path="settings" type="SpeechifyHttpTTSService.Settings" default="None">
  Runtime-configurable settings. See [SpeechifyHttpTTSService
  Settings](#speechifyhttpttsservice-settings) below.
</ParamField>

<ParamField path="text_aggregation_mode" type="TextAggregationMode" default="None">
  How to aggregate incoming text before synthesis. Controls whether text is
  buffered into sentences or sent immediately.
</ParamField>

### SpeechifyHttpTTSService Settings

Runtime-configurable settings passed via the `settings` constructor argument using `SpeechifyHttpTTSService.Settings(...)`. These can be updated mid-conversation with `TTSUpdateSettingsFrame`. See [Service Settings](/pipecat/fundamentals/service-settings) for details.

| Parameter                | Type              | Default     | Description                                                                             |
| ------------------------ | ----------------- | ----------- | --------------------------------------------------------------------------------------- |
| `voice`                  | `str`             | `geffen_32` | Voice identifier (e.g., `geffen_32`, `beatrice_32`).                                    |
| `model`                  | `str`             | `simba-3.2` | Model identifier. Use `simba-3.2` for English or `simba-3.0` for multilingual.          |
| `language`               | `Language \| str` | `None`      | Language for synthesis. Supported: DE, EN, ES, FR, IT, PT. *(Inherited.)*               |
| `loudness_normalization` | `bool \| None`    | `None`      | Whether to normalize audio loudness to a standard level. Adds latency.                  |
| `text_normalization`     | `bool \| None`    | `None`      | Whether to spell out numbers, dates, and similar tokens before synthesis. Adds latency. |

## Usage

### Basic Setup

```python theme={null}
import os
import aiohttp
from pipecat.services.speechify.tts import SpeechifyHttpTTSService

async with aiohttp.ClientSession() as session:
    tts = SpeechifyHttpTTSService(
        api_key=os.getenv("SPEECHIFY_API_KEY"),
        aiohttp_session=session,
        settings=SpeechifyHttpTTSService.Settings(
            voice="geffen_32",
            model="simba-3.2",
        ),
    )
```

### Multilingual Setup

For languages other than English, use the `simba-3.0` model:

```python theme={null}
from pipecat.transcriptions.language import Language

tts = SpeechifyHttpTTSService(
    api_key=os.getenv("SPEECHIFY_API_KEY"),
    aiohttp_session=session,
    settings=SpeechifyHttpTTSService.Settings(
        voice="your_voice_id",
        model="simba-3.0",
        language=Language.ES,
    ),
)
```

### Changing Voice Mid-Conversation

```python theme={null}
from pipecat.frames.frames import TTSUpdateSettingsFrame

# Update to a different voice during the conversation
await worker.queue_frame(
    TTSUpdateSettingsFrame(
        delta=SpeechifyHttpTTSService.Settings(voice="beatrice_32")
    )
)
```

## Notes

* **Speech marks requirement**: Word-level timestamps are only produced by the streaming-native models `simba-3.2` (English) and `simba-3.0` (multilingual). The legacy `simba-english` and `simba-multilingual` models cannot produce speech marks and are rejected by the `/v1/audio/stream/with-timestamps` endpoint.
* **Sample rate validation**: If the requested sample rate is not one of the supported values (8000, 16000, 22050, 24000, 44100, 48000 Hz), the service synthesizes at 24000 Hz by default and logs a warning. The output transport will handle any necessary resampling.
* **Supported languages**: The service supports German (DE), English (EN), Spanish (ES), French (FR), Italian (IT), and Portuguese (PT). Languages outside this set fall back to their BCP-47 tag value with a warning.
* **HTTP-based service**: Unlike WebSocket-based TTS services, `SpeechifyHttpTTSService` processes each synthesis request over HTTP with Server-Sent Events streaming. The service handles interruptions by tracking word-level timestamps.