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Overview

RimeHttpTTSService provides text-to-speech capabilities using Rime AI’s TTS service. It supports streaming audio output and various speech customization options.

You can obtain a Rime API key by signing up at Rime.

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Configuration

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Constructor Parameters

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api_key
str
required

Rime API key

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voice_id
str
default:
"eva"

Rime voice identifier. See Rime’s documentation for supported voices.

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model
str
default:
"mist"

Choose mist for hyper-realistic conversational voices or v1 for Rime’s first-gen model.

​
sample_rate
int
default:
"None"

Output audio sample rate in Hz

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params
InputParams
default:
"InputParams()"

Speech generation parameters

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Output Frames

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Control Frames

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TTSStartedFrame
Frame

Signals start of speech synthesis

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TTSStoppedFrame
Frame

Signals completion of speech synthesis

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Audio Frames

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TTSAudioRawFrame
Frame

Contains generated audio data with: - PCM audio format - Specified sample rate

  • Single channel (mono)

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Error Frames

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ErrorFrame
Frame

Contains Rime TTS error information

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Usage Example

from pipecat.services.rime import RimeHttpTTSService

# Configure service
tts_service = RimeHttpTTSService(
    api_key="your-rime-api-key",
    voice_id="eva",
    model="mist",
    params=RimeHttpTTSService.InputParams(
        speed_alpha=1.2,
        reduce_latency=True
    )
)

# Use in pipeline
pipeline = Pipeline([
    ...,
    llm,
    tts,
    transport.output(),
])

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Frame Flow

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Metrics Support

The service collects processing metrics:

  • Time to First Byte (TTFB)
  • Character usage statistics

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Notes

  • Supports streaming audio output
  • Configurable speech speed
  • Latency optimization options
  • Bracket-based text processing
  • Thread-safe processing
  • Automatic error handling
  • Chunked audio delivery
PlayHTXTTS