Meta Speech-to-Text

Overview

MetaSTTService provides real-time speech-to-text using Meta’s Muse Voice WebSocket API. The service streams audio to Meta’s realtime transcription endpoint and emits interim and final transcription frames. The API key is sent in the handshake frame rather than an HTTP header, and the session’s configuration is fixed once the server accepts the handshake, so a settings change triggers a reconnection.

Meta STT API Reference

Pipecat’s API methods for Meta STT

Voice Example

Complete voice bot example with Meta STT

Transcription Example

Transcription-only example with Meta STT

Meta Voice API Documentation

Official Meta Muse Voice API documentation

Installation

uv add "pipecat-ai[meta]"

Prerequisites

Before using MetaSTTService, you need:

Meta Account: Access to the Meta Model API
API Key: A Meta Model API key for authentication

Required Environment Variables

META_API_KEY: Your Meta Model API key

Configuration

str

required

Meta Model API key, sent as a Bearer token in the handshake.

str

default:"wss://api.meta.ai/v1/asr/realtime"

WebSocket endpoint URL for the Meta STT API.

int

default:"None"

Audio sample rate in Hz. When None, uses the pipeline’s configured sample rate. Audio at anything other than 24000 is resampled to 16000, the only other rate the API accepts.

MetaSTTService.Settings

default:"None"

Runtime-updatable settings overriding defaults. See Settings below.

float

default:"META_TTFS_P99"

P99 latency from speech end to final transcript in seconds. Override for your deployment. See https://github.com/pipecat-ai/stt-benchmark

Settings

Runtime-configurable settings passed via the settings constructor argument using MetaSTTService.Settings(...). These can be updated mid-conversation with STTUpdateSettingsFrame. See Service Settings for details.

Parameter	Type	Default	Description
`model`	`str`	`"muse-voice-transcribe-1.0"`	Meta model to use. (Inherited from base STT settings.)
`language`	`Language \| str`	`Language.EN`	Single language to bias recognition toward. Replaced by `language_bias` when set. Leave both unset for auto-detection. (Inherited from base STT settings.)
`language_bias`	`list[Language]`	`None`	Languages to bias recognition toward, for speech that switches between them. Replaces the single `language` bias when set.
`mode`	`str`	`"ENDPOINTING"`	Segmentation mode: `"ENDPOINTING"` for model-driven turn boundaries, `"PUSH_TO_TALK"` for client-driven turns, or `"DIARIZATION"` for speaker attribution.
`keywords`	`list[str]`	`None`	Terms to bias recognition toward. Biasing raises the odds a term is recognized but doesn’t guarantee its spelling.
`emit_audio_progress`	`bool`	`False`	Whether the server reports progress for every processed audio chunk.
`zdr_override`	`bool \| None`	`None`	Forces metadata-only logging when `True`, or allows content retention when `False`. Leave unset to use the account’s setting.

Supported Languages

Meta STT supports 25 languages for recognition biasing: Arabic, Bengali, German, English, Spanish, French, Hebrew, Hindi, Indonesian, Italian, Japanese, Kannada, Korean, Marathi, Malay, Dutch, Polish, Portuguese, Tamil, Telugu, Thai, Tagalog, Turkish, Vietnamese, Mandarin Chinese

Usage

Basic Setup

from pipecat.services.meta.stt import MetaSTTService
import os

stt = MetaSTTService(
    api_key=os.getenv("META_API_KEY"),
)

With Custom Settings

from pipecat.services.meta.stt import MetaSTTService
from pipecat.transcriptions.language import Language
import os

stt = MetaSTTService(
    api_key=os.getenv("META_API_KEY"),
    settings=MetaSTTService.Settings(
        language=Language.ES,
        keywords=["Pipecat", "AI"],
    ),
)

Multilingual Mode

For speech that switches between languages, use language_bias:

from pipecat.services.meta.stt import MetaSTTService
from pipecat.transcriptions.language import Language
import os

stt = MetaSTTService(
    api_key=os.getenv("META_API_KEY"),
    settings=MetaSTTService.Settings(
        language_bias=[Language.EN, Language.ES, Language.FR],
    ),
)

Push-to-Talk Mode

For client-controlled turn boundaries:

from pipecat.services.meta.stt import MetaSTTService
import os

stt = MetaSTTService(
    api_key=os.getenv("META_API_KEY"),
    settings=MetaSTTService.Settings(
        mode="PUSH_TO_TALK",
    ),
)

Notes

Endpointing modes: In the default ENDPOINTING mode, the server marks turn boundaries itself, emitting speechStart, cumulative partial transcripts, speechEnd, and finally speechComplete with post-processed text. Those boundaries segment transcripts only — Pipecat’s own VAD and turn strategies still decide when the user’s turn ends. In PUSH_TO_TALK mode, the client controls turn boundaries. In DIARIZATION mode, turns are attributed to speakers.
Audio resampling: The API accepts only 16 kHz or 24 kHz audio. Audio at 24 kHz is sent unchanged; any other sample rate is resampled to 16 kHz automatically.
Settings updates: Any settings change triggers a reconnection because Meta fixes the session’s configuration when it accepts the handshake.
Session duration: Sessions are capped at 60 minutes. The server closes the socket when a session reaches that limit, and the base class reconnects into a fresh one.
Language biasing: Meta biases recognition on English language names (e.g., "English", "Mandarin Chinese") rather than codes. An unmapped or unrecognized language degrades to auto-detection.

Event Handlers

Supports the standard service connection events (on_connected, on_disconnected, on_connection_error).

@stt.event_handler("on_connected")
async def on_connected(service):
    print(f"Connected to Meta STT")

@stt.event_handler("on_disconnected")
async def on_disconnected(service):
    print(f"Disconnected from Meta STT")

Get Started

Pipecat Server

Client SDKs

Pipecat Flows

Pipecat Cloud

CLI

Pipecat Context Hub

Meta Speech-to-Text

Overview

Meta STT API Reference

Voice Example

Transcription Example

Meta Voice API Documentation

Installation

Prerequisites

Required Environment Variables

Configuration

Settings

Supported Languages

Usage

Basic Setup

With Custom Settings

Multilingual Mode

Push-to-Talk Mode

Notes

Event Handlers

​Overview

Meta STT API Reference

Voice Example

Transcription Example

Meta Voice API Documentation

​Installation

​Prerequisites

​Required Environment Variables

​Configuration

​Settings

​Supported Languages

​Usage

​Basic Setup

​With Custom Settings

​Multilingual Mode

​Push-to-Talk Mode

​Notes

​Event Handlers

Overview

Installation

Prerequisites

Required Environment Variables

Configuration

Settings

Supported Languages

Usage

Basic Setup

With Custom Settings

Multilingual Mode

Push-to-Talk Mode

Notes

Event Handlers