---
title: Demo Voice Agent Data Eyond
emoji: 🌍
colorFrom: pink
colorTo: pink
sdk: docker
pinned: true
---

# Voice Agent Service

Real-time voice agent backend dengan WebSocket-based STT (Deepgram) dan TTS (Cartesia). Menerima audio stream dari client, mendeteksi wake word, lalu streaming kembali synthesized speech.

**Versi saat ini: Phase 1 (Echo Mode)** — teks setelah wake word langsung di-echo melalui TTS. Phase 2 (LLM + RAG) direncanakan namun belum diimplementasi.

## Requirements

- Python 3.11+
- [uv](https://docs.astral.sh/uv/getting-started/installation/)
- Deepgram API key
- Cartesia API key + Voice ID

## Setup

**1. Clone & install dependencies**
```bash
uv sync
```

**2. Configure environment**
```bash
cp .env.example .env
```

Edit `.env` dan isi API keys:
```env
DEEPGRAM_API_KEY=your_key
CARTESIA_API_KEY=your_key
CARTESIA_VOICE_ID=your_voice_id
```

**Konfigurasi opsional:**
```env
CARTESIA_MODEL=sonic-3               # Default: sonic-3
DEEPGRAM_LANGUAGE=id                 # Default: id (Indonesian)
DEEPGRAM_ENDPOINTING_MS=300          # Default: 300ms
DEEPGRAM_UTTERANCE_END_MS=2000       # Default: 2000ms
SAMPLE_RATE=16000                    # Default: 16000 Hz
WAKE_WORD=Hai EMA                    # Default: "Hai EMA"
```

## Run

```bash
`uv run uvicorn main:app --host 0.0.0.0 --port 7861`
or
`uv run uvicorn main:app --host 0.0.0.0 --port 7861 --reload`

```

Server akan berjalan di `http://localhost:7861`.

## Test

**Health check:**
```bash
curl http://localhost:7861/health
```

Expected response:
```json
{
  "status": "ok",
  "version": "1.1.0",
  "stt_ready": true,
  "tts_ready": true
}
```

Status `degraded` (HTTP 503) akan dikembalikan jika API keys tidak lengkap.

**WebSocket test — kirim audio WAV, terima TTS response:**
```bash
uv run python test_client.py --test audio --wav path/to/audio.wav --save-tts output.wav
```

> File WAV harus dalam format: **16kHz, 16-bit, mono PCM**.

**Test spesifik:**
```bash
uv run python test_client.py --test health      # Health check
uv run python test_client.py --test ping        # Heartbeat ping/pong
uv run python test_client.py --test interrupt   # Cancel ongoing TTS
uv run python test_client.py --test stop        # Graceful disconnect
```

**Connectivity check (tanpa file audio):**
```bash
uv run python test_client.py
```

**Konversi audio M4A ke WAV:**
```bash
uv run python convert_audio.py                     # Konversi semua file di playground/mp4/
uv run python convert_audio.py path/to/file.m4a   # Konversi satu file
```

## Docker

**Build:**
```bash
docker build -t voice-agent .
```

**Run:**
```bash
docker run -p 7861:7861 --env-file .env voice-agent
```

## Wake Word

Default wake word: **"Hai EMA"** (bahasa Indonesia, case-insensitive)

Contoh: ucapkan _"Hai EMA, apa kabar?"_ → agent akan membalas dengan TTS _"apa kabar"_.

Dapat dikonfigurasi via environment variable `WAKE_WORD`.

## Arsitektur

### Alur saat ini (Phase 1 — Echo)

```
Client Audio Stream (PCM 16kHz 16-bit mono)
    ↓
Deepgram STT (nova-2, real-time streaming)
    ↓
Wake Word Detection
    ↓
Echo Response
    ↓
Cartesia TTS (streaming chunks)
    ↓
Client Audio Playback
```

### Alur yang direncanakan (Phase 2 — LLM + RAG)

```
Client Audio Stream
    ↓
Deepgram STT
    ↓
Wake Word Detection
    ↓
PDF Knowledge Base Retrieval (belum diimplementasi)
    ↓
LLM Answer Generation (belum diimplementasi)
    ↓
Cartesia TTS
    ↓
Client Audio Playback
```

## WebSocket Protocol

**Endpoint:** `ws://localhost:7861/ws/voice`

**Client → Server:**

| Type | Format | Keterangan |
|------|--------|------------|
| Binary | PCM audio chunk | Audio 16kHz, 16-bit, mono |
| Text | `{"action": "ping"}` | Heartbeat keep-alive |
| Text | `{"action": "stop"}` | Graceful disconnect |
| Text | `{"action": "interrupt"}` | Cancel ongoing TTS |

**Server → Client:**

| Type | Format | Keterangan |
|------|--------|------------|
| Binary | PCM audio chunk | TTS response audio |
| Text | `{"event": "transcript", "text": "..."}` | Hasil STT |
| Text | `{"event": "reply", "text": "..."}` | Teks setelah wake word |
| Text | `{"event": "tts_end"}` | TTS selesai |
| Text | `{"event": "interrupted"}` | TTS dibatalkan |
| Text | `{"event": "pong"}` | Response ping |
| Text | `{"event": "error", "code": "...", "message": "..."}` | Error |

Lihat [API_CONTRACT.md](API_CONTRACT.md) untuk dokumentasi lengkap WebSocket protocol.

## Struktur Project

```
├── src/
│   ├── config.py              # Konfigurasi & environment variables
│   ├── pipeline.py            # Core voice pipeline (STT → Wake Word → TTS)
│   ├── stt/
│   │   ├── deepgram_client.py # Deepgram real-time STT (aktif)
│   │   └── assemblyai_client.py # AssemblyAI STT (alternatif, tidak digunakan)
│   ├── tts/
│   │   └── cartesia_client.py # Cartesia TTS streaming
│   ├── llm/
│   │   └── answerer.py        # LLM answer generation (Phase 2, belum diimplementasi)
│   └── knowledge/
│       └── loader.py          # PDF loader & RAG (Phase 2, belum diimplementasi)
├── main.py                    # FastAPI entry point & WebSocket handler
├── test_client.py             # Test client
├── convert_audio.py           # Konverter M4A → WAV
├── playground/                # Audio sample dan output TTS
├── Dockerfile
├── .env.example
└── API_CONTRACT.md
```