Developer Docs

Seeduplex API

Integrate full-duplex voice AI into your application. Real-time, bidirectional audio streaming.

Quick Start

1. Install

bash

npm install @bytedance/seed-sdk

2. Initialize Client

typescript

import { SeedClient } from '@bytedance/seed-sdk';

const client = new SeedClient({
  apiKey: process.env.SEED_API_KEY,
});

3. Create a Full-Duplex Session

typescript

const session = await client.voice.createSession({
  model: 'seeduplex-v1',
  mode: 'full-duplex',
  language: 'en',           // 'en' | 'zh' | 'auto'
  sampleRate: 16000,        // 8000 | 16000 | 24000
  channels: 1,
});

4. Stream Audio

typescript

// Receive audio from the model
session.on('audio', (chunk: Buffer) => {
  audioOutput.write(chunk);
});

// Handle turn-taking events
session.on('turn_start', () => {
  console.log('Model started speaking');
});

session.on('turn_end', () => {
  console.log('Model finished speaking');
});

session.on('interruption', () => {
  console.log('User interrupted — model yielding');
  audioOutput.flush();
});

// Send mic audio in real-time
microphoneStream.on('data', (chunk: Buffer) => {
  session.sendAudio(chunk);
});

// End session
await session.close();

Events Reference

Event	Payload	Description
`audio`	Buffer	Audio chunk from the model (PCM)
`transcript`	{ text, isFinal }	Transcription of user speech
`response`	{ text, isFinal }	Model response text
`turn_start`	—	Model began speaking
`turn_end`	—	Model finished its turn
`interruption`	—	User interrupted; model yields
`error`	Error	Session error
`close`	—	Session closed

Session Configuration

Parameter	Type	Default	Description
`model`	string	seeduplex-v1	Model version
`mode`	"full-duplex" \| "half-duplex"	full-duplex	Interaction mode
`language`	"en" \| "zh" \| "auto"	auto	Primary language
`sampleRate`	8000 \| 16000 \| 24000	16000	Audio sample rate (Hz)
`channels`	1 \| 2	1	Audio channels
`noiseSuppress`	boolean	true	Enable noise suppression
`sensitivity`	"low" \| "medium" \| "high"	medium	Turn-detection sensitivity
`systemPrompt`	string	—	Persona / system instructions

Pricing

Free

100 min/month

Full-duplex sessions
All languages
Email support

Pro

$0.008

per minute

Everything in Free
Unlimited minutes
Priority support
99.9% SLA

Enterprise

Custom

Custom rate limits
Dedicated capacity
On-prem option
SLA + support

Browser Integration (WebRTC)

For web applications, stream audio via WebRTC for lowest latency:

javascript

// Browser-side WebRTC integration
const stream = await navigator.mediaDevices.getUserMedia({ audio: true });
const mediaRecorder = new MediaRecorder(stream, { mimeType: 'audio/webm' });

const session = await client.voice.createSession({
  model: 'seeduplex-v1',
  transport: 'webrtc',
});

mediaRecorder.ondataavailable = (e) => {
  session.sendAudio(e.data);
};

session.on('audio', (chunk) => {
  // Play audio chunk through Web Audio API
  audioContext.decodeAudioData(chunk, (buffer) => {
    const source = audioContext.createBufferSource();
    source.buffer = buffer;
    source.connect(audioContext.destination);
    source.start();
  });
});

mediaRecorder.start(20); // 20ms chunks for low latency

Get API Access

Seed API access is rolling out in waves. Apply for early access at seed.bytedance.com.

Apply for Early Access