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Overview

PlayHT provides two TTS service implementations:

  • PlayHTTTSService: WebSocket-based service with real-time streaming
  • PlayHTHttpTTSService: HTTP-based service for simpler, non-streaming synthesis

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Installation

To use PlayHT services, install the required dependencies:

pip install pipecat-ai[playht]

You’ll also need to set up your PlayHT credentials as environment variables:

  • PLAY_HT_USER_ID
  • PLAY_HT_API_KEY

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PlayHTTTSService

WebSocket-based implementation supporting real-time streaming synthesis.

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Constructor Parameters

api_key
str
required

PlayHT API key

user_id
str
required

PlayHT user ID

voice_url
str
required

Voice identifier URL

voice_engine
str
default: "PlayHT3.0-mini"

TTS engine identifier. See the PlayHT docs for available engines.

sample_rate
int
default: "24000"

Output audio sample rate in Hz

output_format
str
default: "wav"

Audio output format

text_filter
BaseTextFilter
default: "None"

Modifies text provided to the TTS. Learn more about the available filters.

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Input Parameters

class InputParams(BaseModel):
    language: Optional[Language] = Language.EN
    speed: Optional[float] = 1.0
    seed: Optional[int] = None

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PlayHTHttpTTSService

HTTP-based implementation for simpler synthesis requirements.

​
Constructor Parameters

api_key
str
required

PlayHT API key

user_id
str
required

PlayHT user ID

voice_url
str
required

Voice identifier URL

voice_engine
str
default: "PlayHT3.0-mini"

TTS engine identifier. See the PlayHT docs for available engines.

sample_rate
int
default: "24000"

Output audio sample rate in Hz

​
Input Parameters

class InputParams(BaseModel):
    language: Optional[Language] = Language.EN
    speed: Optional[float] = 1.0
    seed: Optional[int] = None

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Output Frames

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Control Frames

TTSStartedFrame
Frame

Signals start of synthesis

TTSStoppedFrame
Frame

Signals completion of synthesis

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Audio Frames

TTSAudioRawFrame
Frame

Contains generated audio data with: - WAV format - Specified sample rate - Single channel (mono)

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Error Frames

ErrorFrame
Frame

Contains PlayHT error information

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Methods

See the TTS base class methods for additional functionality.

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Language Support

Supports multiple languages when using the PlayHT3.0-mini engine:

Language CodeDescriptionService Code
Language.BGBulgarianBULGARIAN
Language.CACatalanCATALAN
Language.CSCzechCZECH
Language.DADanishDANISH
Language.DEGermanGERMAN
Language.ENEnglishENGLISH
Language.ESSpanishSPANISH
Language.FRFrenchFRENCH
Language.ELGreekGREEK
Language.HIHindiHINDI
Language.HUHungarianHUNGARIAN
Language.IDIndonesianINDONESIAN
Language.ITItalianITALIAN
Language.JAJapaneseJAPANESE
Language.KOKoreanKOREAN
Language.MSMalayMALAY
Language.NLDutchDUTCH
Language.PLPolishPOLISH
Language.PTPortuguesePORTUGUESE
Language.RURussianRUSSIAN
Language.SVSwedishSWEDISH
Language.THThaiTHAI
Language.TRTurkishTURKISH
Language.UKUkrainianUKRAINIAN

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Usage Examples

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WebSocket Service

# Configure WebSocket service
ws_service = PlayHTTTSService(
    api_key="your-api-key",
    user_id="your-user-id",
    voice_url="voice-url",
    voice_engine="PlayHT3.0-mini",
    params=PlayHTTTSService.InputParams(
        language=Language.EN,
        speed=1.2
    )
)

# Use in pipeline
pipeline = Pipeline([
    text_input,
    ws_service,
    audio_output
])

​
HTTP Service

# Configure HTTP service
http_service = PlayHTHttpTTSService(
    api_key="your-api-key",
    user_id="your-user-id",
    voice_url="voice-url",
    voice_engine="PlayHT3.0-mini",
    params=PlayHTHttpTTSService.InputParams(
        language=Language.EN,
        speed=1.0
    )
)

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Frame Flow

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WebSocket Service

​
HTTP Service

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Metrics Support

Both services collect processing metrics:

  • Time to First Byte (TTFB)
  • Processing duration
  • Character usage
  • API calls

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Notes

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WebSocket Service

  • Real-time streaming support
  • Automatic reconnection
  • Interruption handling
  • WAV header management
  • Thread-safe processing

​
HTTP Service

  • Simpler implementation
  • Complete audio delivery
  • WAV header parsing
  • Chunked audio delivery
  • Lower latency for short texts

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Common Features

  • Multiple voice engines
  • Speed control
  • Language support
  • Seed-based consistency
  • Error handling
  • Metrics collection
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