Soniox Python SDK

The SDK exposes two clients: SonioxClient (sync) and AsyncSonioxClient (async). Each client supports:

• STT over REST (client.stt) and realtime WebSocket (client.realtime.stt)
• TTS over REST (client.tts) and realtime WebSocket (client.realtime.tts)
• voice cloning (client.voices) - clone a voice from a reference clip and use it in TTS
• usage and cost (client.usage, client.usage_logs) - daily spend per model, and per-request logs
• auth, file uploads, model listing, webhooks, and typed request/response models

Install

pip install soniox
# or if using uv
uv add soniox
export SONIOX_API_KEY=<your-key>

Get your API key from the Soniox Console and inject it once per shell session. Both clients read SONIOX_API_KEY by default, but you can override it per-client if needed.

Avoid Python 3.13.6 - it has a regression in ssl that hangs realtime STT/TTS (CPython issue #137583). Use any other 3.10-3.13.x.

Quick run (STT + TTS, REST + realtime)

1. REST STT transcription: transcribe a local file end-to-end in one call. Full example: examples/soniox_client/api_example.py.

from soniox import SonioxClient

client = SonioxClient()
transcript = client.stt.transcribe_and_wait_with_tokens(
    file="path/to/audio.mp3",                # local file
    # audio_url="https://example.com/audio.mp3",  # or remote URL
    delete_after=True,                        # auto-cleanup file + transcription
)
print(transcript.text)
client.close()

2. REST TTS generation: convert text to an audio file.

from soniox import SonioxClient
from soniox.utils import output_file_for_audio_format

client = SonioxClient()
output_file = output_file_for_audio_format("wav", "tts_sync_output")
written = client.tts.generate_to_file(
    output_file,
    text="Hello from Soniox Python SDK Text-to-Speech.",
    model="tts-rt-v2",
    language="en",
    voice="Adrian",
    audio_format="wav",
)
print(f"Wrote {written} bytes to {output_file.resolve()}")
client.close()

Run the full example at examples/soniox_client/tts_api_example.py or async version at examples/async_soniox_client/tts_api_example.py.

The voice above is a built-in voice name. You can also clone a voice from a reference audio clip and pass the returned voice id as voice:

voice = client.voices.create("reference.wav", name="my-cloned-voice")
# Cloning runs asynchronously; poll client.voices.get(voice.id) until a model
# reports status "ready", then synthesize with voice=voice.id.

See the voice cloning guide for details.

Output settings that are not identity - speed, reduce_silence, sample rate, bitrate - go on CreateTtsConfig:

from soniox.types import CreateTtsConfig

client.tts.generate(
    text="Hello.",
    voice="Adrian",
    model="tts-rt-v2",
    language="en",
    config=CreateTtsConfig(speed=1.1, reduce_silence=True),
)

reduce_silence shortens the pauses between words and is only accepted by models whose supports_silence_reduction is true in client.tts_models.list().

3. Realtime STT streaming: open client.realtime.stt.connect, call session.send_byte_chunk or session.send_bytes, then iterate session.receive_events() to render tokens:

from soniox import SonioxClient
from soniox.types import RealtimeSTTConfig, Token
from soniox.utils import render_tokens, throttle_audio, start_audio_thread

DEMO_FILE = "path_to_your_audio_file"

client = SonioxClient()
config = RealtimeSTTConfig(model="stt-rt-v5", audio_format="mp3")
final_tokens: list[Token] = []
non_final_tokens: list[Token] = []

def realtime():
    with client.realtime.stt.connect(config=config) as session:
        start_audio_thread(session, throttle_audio(DEMO_FILE, delay_seconds=0.1))
        for event in session.receive_events():
            for token in event.tokens:
                if token.is_final:
                    final_tokens.append(token)
                else:
                    non_final_tokens.append(token)
            print(render_tokens(final_tokens, non_final_tokens))
            non_final_tokens.clear()

realtime()
client.close()

See examples/soniox_client/realtime_example.py for the full flow.

4. Realtime TTS streaming: send text chunks and write audio to a file as it arrives.

from uuid import uuid4

from soniox import SonioxClient
from soniox.types import RealtimeTTSConfig
from soniox.utils import output_file_for_audio_format

client = SonioxClient()
config = RealtimeTTSConfig(
    stream_id=f"sync-{uuid4()}",
    model="tts-rt-v2",
    language="en",
    voice="Adrian",
    audio_format="wav",
)

output_file = output_file_for_audio_format("wav", "tts_realtime_output")
bytes_written = 0
with client.realtime.tts.connect(config=config) as session, output_file.open("wb") as f:
    session.send_text_chunks(
        ["Hello from realtime TTS. ", "This is the final chunk."],
        text_end=True,
    )
    for chunk in session.receive_audio_chunks():
        f.write(chunk)
        bytes_written += len(chunk)

print(f"Wrote {bytes_written} bytes to {output_file.resolve()}")

Run the full example at examples/soniox_client/tts_realtime_example.py or async version at examples/async_soniox_client/tts_realtime_example.py.

Usage and cost

client.usage.summary() returns daily cost and activity for the project, rolled up per model and across all models. start_time is inclusive, end_time exclusive, both ISO 8601 UTC, and the window may span at most 366 days.

summary = client.usage.summary(
    start_time="2026-04-01T00:00:00Z",
    end_time="2026-05-01T00:00:00Z",
)
print(summary.total.total_cost_usd)
for entry in summary.models:
    print(entry.model, entry.total_cost_usd)

Each entry carries a days list plus per-day lists (cost_usd, num_requests, ...) aligned to it by index. For per-request records instead, use client.usage_logs.list() / list_all().

client.concurrency_limits covers concurrency: get() for current counts and configured limits, history() for past peaks aggregated per minute (60), hour (3600), or day (86400).

history = client.concurrency_limits.history(
    "2026-04-28T09:00:00Z",
    "2026-04-28T10:00:00Z",
    period_sec=60,
    kind="tts",
)
peak = max(entry.sample_max for entry in history.entries)

Repository layout

• src/soniox/ – sdk code (clients, http namespaces, real-time/session helpers, types, utils).
• examples/soniox_client & examples/async_soniox_client – runnable STT and TTS examples for sync and async clients.
• docs/ – markdown reference (async_client.md, realtime_client.md, types.md, utils.md) generated by scripts/generate_docs.py.
• assets/ – sample audio referenced by the examples.

Development

uv install --with dev

This pulls in ruff, pyright, pytest, etc., so you can lint, type-check, test, and regenerate docs locally.

Docs

source .venv/bin/activate
python3 scripts/generate_docs.py

Docs are output to /docs directory.

Resources

• soniox.com/docs – official Soniox documentation.
• GitHub repo – source, examples, and scripts.
• PyPI
• Support: support@soniox.com.