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Description:

alexaclient 1.5.1

Alexa Voice Service Client

Python Client for Alexa Voice Service (AVS)

Installation
pip install alexa_client

or if you want to run the demos:
pip install alexa_client[demo]

Usage
File audio
from alexa_client import AlexaClient

client = AlexaClient(
client_id='my-client-id',
secret='my-secret',
refresh_token='my-refresh-token',
)
client.connect() # authenticate and other handshaking steps
with open('./tests/resources/alexa_what_time_is_it.wav', 'rb') as f:
for i, directive in enumerate(client.send_audio_file(f)):
if directive.name in ['Speak', 'Play']:
with open(f'./output_{i}.mp3', 'wb') as f:
f.write(directive.audio_attachment)

Now listen to output_0.wav and Alexa should tell you the time.
Microphone audio
import io

from alexa_client import AlexaClient
import pyaudio

def callback(in_data, frame_count, time_info, status):
buffer.write(in_data)
return (in_data, pyaudio.paContinue)

p = pyaudio.PyAudio()
stream = p.open(
format=pyaudio.paInt16,
channels=1,
rate=16000,
input=True,
stream_callback=callback,
)

client = AlexaClient(
client_id='my-client-id',
secret='my-secret',
refresh_token='my-refresh-token',
)

buffer = io.BytesIO()
try:
stream.start_stream()
print('listening. Press CTRL + C to exit.')
client.connect()
for i, directive in enumerate(client.send_audio_file(buffer)):
if directive.name in ['Speak', 'Play']:
with open(f'./output_{i}.mp3', 'wb') as f:
f.write(directive.audio_attachment)
finally:
stream.stop_stream()
stream.close()
p.terminate()

Multi-step requests
An Alexa command may relate to a previous command e.g,
[you] "Alexa, play twenty questions"
[Alexa] "Is it a animal, mineral, or vegetable?"
[you] "Mineral"
[Alexa] "Is it valuable"
[you] "No"
[Alexa] "is it..."
This can be achieved by passing the same dialog request ID to multiple send_audio_file calls:
from alexa_client.alexa_client import helpers

dialog_request_id = helpers.generate_unique_id()
directives_one = client.send_audio_file(audio_one, dialog_request_id=dialog_request_id)
directives_two = client.send_audio_file(audio_two, dialog_request_id=dialog_request_id)
directives_three = client.send_audio_file(audio_three, dialog_request_id=dialog_request_id)

Run the streaming microphone audio demo to use this feature:
pip install alexa_client[demo]
python -m alexa_client.demo.streaming_microphone \
--client-id="{enter-client-id-here}" \
--client-secret="{enter-client-secret-here}" \
--refresh-token="{enter-refresh-token-here}"

ASR Profiles
Automatic Speech Recognition (ASR) profiles optimized for user speech from varying distances. By default CLOSE_TALK is used but this can be specified:
from alexa_client import constants

client.send_audio_file(
audio_file=audio_file,
distance_profile=constants.NEAR_FIELD, # or constants.FAR_FIELD
)

Audio format
By default PCM audio format is assumed, but OPUS can be specified:
from alexa_client import constants

client.send_audio_file(
audio_file=audio_file,
audio_format=constants.OPUS,
)

When PCM format is specified the audio should be 16bit Linear PCM (LPCM16), 16kHz sample rate, single-channel, and little endian.
When OPUS forat is specified the audio should be 16bit Opus, 16kHz sample rate, 32k bit rate, and little endian.
Base URL
base_url can be set to improve latency. Choose a region closest to your location.
from alexa_client.alexa_client import constants

client = AlexaClient(
client_id='my-client-id',
secret='my-secret',
refresh_token='my-refresh-token',
base_url=constants.BASE_URL_ASIA
)

The default base URL is Europe. The available constants are BASE_URL_EUROPE, BASE_URL_ASIA and BASE_URL_NORTH_AMERICA but you can pass any string if required.
Read more
Authentication
To use AVS you must first have a developer account. Then register your product here. Choose "Application" under "Is your product an app or a device"?
The client requires your client_id, secret and refresh_token:

client kwarg
Notes

client_id
Retrieve by clicking on the your product listed here

secret
Retrieve by clicking on the your product listed here

refresh_token
You must generate this. See below

Refresh token
You will need to login to Amazon via a web browser to get your refresh token.
To enable this first go here and click on your product to set some security settings under Security Profile:

setting
value

Allowed Origins
http://localhost:9000

Allowed Return URLs
http://localhost:9000/callback/

Note what you entered for Product ID under Product Information, as this will be used as the device-type-id (case sensitive!)
Then run:
python -m alexa_client.refreshtoken.serve \
--device-type-id="{enter-device-type-id-here}" \
--client-id="{enter-client-id-here}" \
--client-secret="{enter-client-secret-here}"

Follow the on-screen instructions shown at http://localhost:9000 in your web browser.
On completion Amazon will return your refresh_token - which you will require to send audio or recorded voice.
Steaming audio to AVS
AlexaClient.send_audio_file streaming uploads a file-like object to AVS for great latency. The file-like object can be an actual file on your filesystem, an in-memory BytesIo buffer containing audio from your microphone, or even audio streaming from your browser over a websocket in real-time.
Persistent AVS connection
Calling AlexaClient.connect creates a persistent connection to AVS. A thread runs that pings AVS after 4 minutes of no request being made to AVS. This prevents the connection getting forcefully closed due to inactivity.
Unit test
To run the unit tests, call the following commands:
git clone git@github.com:richtier/alexa-voice-service-client.git
make test_requirements
pytest

Other projects
This library is used by alexa-browser-client, which allows you to talk to Alexa from your browser.