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196# -*- coding: utf-8 -*-
# Copyright 2025 Google LLC
#
# Written by:
# - Freddy Boulton (https://github.com/freddyaboulton)
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
## Setup
This script launches a pure-python web-based UI for the Gen AI SDK Voice Chat.
To install the dependencies for this script, run:
```
pip install fastrtc google-genai python-dotenv
```
If the `GOOGLE_API_KEY` environment variable is set,
it will automatically be used. Otherwise, you will be prompted
to enter it.
## Run
To run the script:
```
python live_api_ui.py
```
"""
import asyncio
import base64
import os
from typing import Literal
import gradio as gr
import numpy as np
from fastrtc import (
AsyncStreamHandler,
WebRTC,
wait_for_item,
)
from google import genai
from google.genai.types import (
LiveConnectConfig,
PrebuiltVoiceConfig,
SpeechConfig,
VoiceConfig,
)
try:
from dotenv import load_dotenv
load_dotenv()
except (ImportError, ModuleNotFoundError):
pass
class GeminiHandler(AsyncStreamHandler):
"""Handler for the Gemini API"""
def __init__(
self,
expected_layout: Literal["mono"] = "mono",
output_sample_rate: int = 24000,
output_frame_size: int = 480,
) -> None:
super().__init__(
expected_layout,
output_sample_rate,
output_frame_size,
input_sample_rate=16000,
)
self.input_queue: asyncio.Queue = asyncio.Queue()
self.output_queue: asyncio.Queue = asyncio.Queue()
self.quit: asyncio.Event = asyncio.Event()
def copy(self) -> "GeminiHandler":
return GeminiHandler(
expected_layout="mono",
output_sample_rate=self.output_sample_rate,
output_frame_size=self.output_frame_size,
)
async def start_up(self):
await self.wait_for_args()
api_key, voice_name = self.latest_args[1:]
client = genai.Client(
api_key=api_key or os.getenv("GEMINI_API_KEY"),
http_options={"api_version": "v1alpha"},
)
config = LiveConnectConfig(
response_modalities=["AUDIO"], # type: ignore
speech_config=SpeechConfig(
voice_config=VoiceConfig(
prebuilt_voice_config=PrebuiltVoiceConfig(
voice_name=voice_name,
)
)
),
)
async with client.aio.live.connect(
model="gemini-2.5-flash-lite", config=config
) as session:
async for audio in session.start_stream(
stream=self.stream(), mime_type="audio/pcm"
):
if audio.data:
array = np.frombuffer(audio.data, dtype=np.int16)
self.output_queue.put_nowait((self.output_sample_rate, array))
async def stream(self):
while not self.quit.is_set():
yield await wait_for_item(self.input_queue)
async def receive(self, frame: tuple[int, np.ndarray]) -> None:
_, array = frame
array = array.squeeze()
audio_message = base64.b64encode(array.tobytes()).decode("UTF-8")
self.input_queue.put_nowait(audio_message)
async def emit(self) -> tuple[int, np.ndarray] | None:
return await wait_for_item(self.output_queue)
def shutdown(self) -> None:
self.quit.set()
with gr.Blocks() as demo:
gr.HTML(
"""
<div style='text-align: center'>
<h1>Gen AI SDK Voice Chat</h1>
<p>Speak with Gemini using real-time audio streaming</p>
<p>Get an API Key <a href="https://support.google.com/googleapi/answer/6158862?hl=en">here</a></p>
</div>
"""
)
with gr.Row() as api_key_row:
api_key = gr.Textbox(
label="API Key",
placeholder="Enter your API Key",
value=os.getenv("GOOGLE_API_KEY", ""),
type="password",
)
with gr.Row(visible=False) as row:
with gr.Column():
webrtc = WebRTC(
label="Audio",
modality="audio",
mode="send-receive",
pulse_color="rgb(35, 157, 225)",
icon_button_color="rgb(255, 255, 255)",
icon="https://www.gstatic.com/lamda/images/gemini_favicon_f069958c85030456e93de685481c559f160ea06b.png",
)
voice = gr.Dropdown(
label="Voice",
choices=[
"Puck",
"Charon",
"Kore",
"Fenrir",
"Aoede",
],
value="Puck",
)
webrtc.stream(
GeminiHandler(),
inputs=[webrtc, api_key, voice],
outputs=[webrtc],
time_limit=90,
concurrency_limit=2,
)
api_key.submit(
lambda: (gr.update(visible=False), gr.update(visible=True)),
None,
[api_key_row, row],
)
if __name__ == "__main__":
demo.launch()