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time speech recognition (Qwen-ASR-Realtime)-Qwen-ASR-Realtime Python SDK - API reference
Stream audio to Qwen-ASR-Realtime over WebSocket and receive real-time transcription results via the DashScope Python SDK.
For an overview of supported models, features, and complete sample code, see Real-time speech recognition.
Prerequisites
Before you begin, make sure that you have:
DashScope SDK 1.25.6 or later
An API key
An understanding of the interaction flow
Request parameters
OmniRealtimeConversation constructor
Create an OmniRealtimeConversation instance with the following parameters. Click to view sample code
HELPCODEESCAPE-python
from dashscope.audio.qwen_omni import OmniRealtimeConversation, OmniRealtimeCallback
class MyCallback(OmniRealtimeCallback):
"""Callback for real-time recognition"""
def __init__(self, conversation):
self.conversation = conversation
self.handlers = {
'session.created': self._handle_session_created,
'conversation.item.input_audio_transcription.completed': self._handle_final_text,
'conversation.item.input_audio_transcription.text': self._handle_stash_text,
'input_audio_buffer.speech_started': lambda r: print('======Speech Start======'),
'input_audio_buffer.speech_stopped': lambda r: print('======Speech Stop======')
}
def on_open(self):
print('Connection opened')
def on_close(self, code, msg):
print(f'Connection closed, code: {code}, msg: {msg}')
def on_event(self, response):
try:
handler = self.handlers.get(response['type'])
if handler:
handler(response)
except Exception as e:
print(f'[Error] {e}')
def _handle_session_created(self, response):
print(f"Start session: {response['session']['id']}")
def _handle_final_text(self, response):
print(f"Final recognized text: {response['transcript']}")
def _handle_stash_text(self, response):
print(f"Got stash result: {response['stash']}")
conversation = OmniRealtimeConversation(
model='qwen3-asr-flash-realtime',
# The following URL is for the Chinese mainland. For regions outside
# the Chinese mainland, use
# wss://dashscope-intl.aliyuncs.com/api-ws/v1/realtime instead.
url='wss://dashscope.aliyuncs.com/api-ws/v1/realtime',
callback=MyCallback(conversation=None) # Temporarily pass None and inject it later.
)
conversation.callback.conversation = conversation| Parameter | Type | Required | Description |
|---|---|---|---|
model | str | Yes | Model to use. |
callback | OmniRealtimeCallback | Yes | Callback object that handles server-side events. |
url | str | Yes | WebSocket endpoint. Chinese mainland: wss://dashscope.aliyuncs.com/api-ws/v1/realtime International: wss://dashscope-intl.aliyuncs.com/api-ws/v1/realtime |
Session configuration
After connecting, call update_session to configure session parameters. Click to view sample code
HELPCODEESCAPE-python
from dashscope.audio.qwen_omni import TranscriptionParams, MultiModality
transcription_params = TranscriptionParams(
language='zh',
sample_rate=16000,
input_audio_format="pcm"
)
conversation.update_session(
output_modalities=[MultiModality.TEXT],
enable_turn_detection=True,
turn_detection_type="server_vad",
turn_detection_threshold=0.0,
turn_detection_silence_duration_ms=400,
enable_input_audio_transcription=True,
transcription_params=transcription_params
)| Parameter | Type | Required | Description |
|---|---|---|---|
output_modalities | List\[MultiModality\] | Yes | Output modality. Fixed to \[MultiModality.TEXT\]. |
enable_turn_detection | bool | No | Enables server-side Voice Activity Detection (VAD). Default: True. When False, call commit() manually to trigger recognition. |
turn_detection_type | str | No | Server-side VAD type. Fixed to server_vad. |
turn_detection_threshold | float | No | VAD sensitivity threshold. Default: 0.2. Recommended: 0.0. Valid range: \[-1, 1\]. Lower values = higher sensitivity (may trigger on background noise). Higher values = fewer false triggers in noisy environments. |
turn_detection_silence_duration_ms | int | No | Silence duration (ms) that marks the end of a statement. Default: 800. Recommended: 400. Valid range: \[200, 6000\]. Lower values (e.g., 300 ms) = faster response but may split natural pauses. Higher values (e.g., 1200 ms) = better handling of long-sentence pauses but higher latency. |
transcription_params | TranscriptionParams | No | Speech recognition configurations. See TranscriptionParams . |
TranscriptionParams
Configure speech recognition settings with the TranscriptionParams constructor. Click to view sample code
HELPCODEESCAPE-python
transcription_params = TranscriptionParams(
language='zh',
sample_rate=16000,
input_audio_format="pcm"
)| Parameter | Type | Required | Description |
|---|---|---|---|
language | str | No | Source language of the audio. Supported values: zh (Chinese: Mandarin, Sichuanese, Minnan, Wu), yue (Cantonese), en (English), ja (Japanese), ko (Korean), de (German), fr (French), es (Spanish), pt (Portuguese), it (Italian), ru (Russian), ar (Arabic), hi (Hindi), id (Indonesian), th (Thai), tr (Turkish), uk (Ukrainian), vi (Vietnamese), cs (Czech), da (Danish), fi (Finnish), fil (Filipino), is (Icelandic), ms (Malay), no (Norwegian), pl (Polish), sv (Swedish) |
sample_rate | int | No | Audio sampling rate in Hz. Default: 16000. Supported: 16000, 8000. With 8000, the server upsamples to 16,000 Hz before recognition, which may add minor latency. Use 8000 only for 8 kHz source audio like telephone recordings. |
input_audio_format | str | No | Audio format. Default: pcm. Supported: pcm, opus. |
corpus_text | str | No | Background text, entity vocabularies, or other reference information for contextual biasing. Max: 10,000 tokens. For details, see Contextual biasing. |
Key interfaces
OmniRealtimeConversation class
HELPCODEESCAPE-python
from dashscope.audio.qwen_omni import OmniRealtimeConversation| Method | Server response event | Description |
|---|---|---|
connect() | session.created, session.updated | Opens a WebSocket connection to the server. |
update_session(...) | session.updated | Configures the session. Call after connect(). If omitted, defaults apply. See Session configuration for parameters. |
append_audio(audio_b64: str) | None | Sends a Base64-encoded audio chunk to the server input buffer. With enable_turn_detection=True, the server detects speech boundaries and commits automatically. With enable_turn_detection=False, the client controls commit timing (max 15 MiB per event). Smaller chunks improve VAD responsiveness. |
commit() | input_audio_buffer.committed | Commits buffered audio for recognition. Returns an error if the buffer is empty. Disabled when enable_turn_detection=True. |
end_session(timeout: int = 20) | session.finished | Ends the session after the server completes final recognition. In VAD mode (default), call after sending all audio. In Manual mode, call after commit(). Async variant: end_session_async(). |
close() | None | Terminates the task and closes the connection. |
get_session_id() | None | Returns the current session ID. |
get_last_response_id() | None | Returns the most recent response ID. |
OmniRealtimeCallback interface
Subclass OmniRealtimeCallback and implement its methods to handle server events.
HELPCODEESCAPE-python
from dashscope.audio.qwen_omni import OmniRealtimeCallback| Method | Parameters | Description |
|---|---|---|
on_open() | None | Called when the WebSocket connection is established. |
on_event(message: dict) | message: a server event | Called when a server event is received. |
on_close(close_status_code, close_msg) | close_status_code: status code; close_msg: log message | Called when the WebSocket connection is closed. |