Speechmatics STT

SpeechmaticsSTT adapts the official speechmatics-voice SDK to Patter’s pipeline mode. It streams PCM audio to Speechmatics’s real-time API and yields Transcript events for partial and final segments. The Voice SDK is imported lazily so consumers that do not install the speechmatics extra can still import the rest of getpatter.

Install

pip install "getpatter[speechmatics]"

Usage

Use the namespaced import (getpatter.stt.speechmatics) or the flat alias (getpatter.SpeechmaticsSTT). Both auto-resolve SPEECHMATICS_API_KEY from the environment when api_key= is omitted. Override the realtime URL via SPEECHMATICS_RT_URL for self-hosted deployments.

# Namespaced import
from getpatter.stt import speechmatics

stt = speechmatics.STT()                                  # reads SPEECHMATICS_API_KEY
stt = speechmatics.STT(api_key="...", language="en")

# Flat alias (equivalent)
from getpatter import SpeechmaticsSTT

stt = SpeechmaticsSTT()

// Speechmatics is currently a Python-only provider.
// See typescript-sdk/providers/speechmatics for the parity status.

Plug it into an agent:

import asyncio
from getpatter import Patter, Twilio, SpeechmaticsSTT, ElevenLabsTTS

phone = Patter(carrier=Twilio(), phone_number="+15550001234")

agent = phone.agent(
    stt=SpeechmaticsSTT(language="en"),                   # SPEECHMATICS_API_KEY from env
    tts=ElevenLabsTTS(voice_id="rachel"),
    system_prompt="You are a helpful assistant.",
)

asyncio.run(phone.serve(agent))

Models and rates

Speechmatics bills per minute of streamed audio. Default rate from getpatter.pricing:

Tier	Rate / min
Pro (default)	$0.004

($0.24/hr = $0.004/min. Override per-call via Patter(pricing={"speechmatics": {"price": ...}}).) The operating_point option toggles enhanced (higher accuracy) vs standard (lower latency); both bill at the same Pro tier rate.

Languages

language="en" by default. Speechmatics supports 50+ languages ("es", "fr", "de", "it", "pt", "nl", "ja", "zh", …). Pair with output_locale="en-GB" to bias the output spelling for a specific locale, and domain="finance" (or "medical") to apply a domain language pack when available.

Turn detection

Speechmatics supports four end-of-turn detection modes via turn_detection_mode:

Mode	When to use
`ADAPTIVE` (default)	Server-side adaptive detection — best general-purpose pick.
`FIXED`	Hard timeout — predictable latency, may cut speech off.
`EXTERNAL`	Disable server-side detection when pairing with an external VAD.
`SMART_TURN`	Speechmatics’s ML-based turn classifier (preview tier).

Options

Option	Default	Notes
`api_key`	`None`	Reads from `SPEECHMATICS_API_KEY` when omitted.
`base_url`	SDK default	Override via `SPEECHMATICS_RT_URL` for self-hosted deployments.
`language`	`"en"`	BCP-47 code.
`turn_detection_mode`	`ADAPTIVE`	See the table above.
`sample_rate`	`16000`	8000, 16000, 44100 Hz.
`enable_diarization`	`False`	Server-side speaker IDs.
`max_delay`	`None`	Max latency (s) before finals, range `[0.7, 4.0]`.
`end_of_utterance_silence_trigger`	`None`	Silence (s) that triggers EOU, range `(0, 2)`.
`end_of_utterance_max_delay`	`None`	Max EOU delay (s); must exceed the silence trigger.
`include_partials`	`True`	Emit interim transcripts.
`additional_vocab`	`None`	Custom vocabulary boost list (`AdditionalVocabEntry` from the SDK).
`operating_point`	`None`	`ENHANCED` (accuracy) or `STANDARD` (latency).
`domain`	`None`	Domain language pack (`"finance"`, `"medical"`, …).
`output_locale`	`None`	Spelling locale (`"en-GB"`, `"en-US"`, …).

Low-level usage

from getpatter.providers.speechmatics_stt import SpeechmaticsSTT, TurnDetectionMode

stt = SpeechmaticsSTT(
    api_key="...",
    language="en",
    turn_detection_mode=TurnDetectionMode.ADAPTIVE,
)
await stt.connect()
await stt.send_audio(pcm_chunk)                           # 16 kHz PCM s16le
async for t in stt.receive_transcripts():
    print(t.text, t.is_final, t.confidence)
await stt.close()

​Speechmatics STT

​Install

​Usage

​Models and rates

​Languages

​Turn detection

​Options

​Low-level usage

Speechmatics STT

Install

Usage

Models and rates

Languages

Turn detection

Options

Low-level usage