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🎙️ Kokoro TTS

All-in-One Docker image for Kokoro-82M Text-to-Speech

Web UI • REST API • WebSocket • Streaming • Batch • MCP

✨ Features

• 🎨 Beautiful Web UI - Modern interface with real-time audio playback

• 🔌 REST API - Full-featured HTTP endpoints with Swagger docs

• 📡 WebSocket - Real-time bidirectional TTS communication

• 🌊 Streaming - Audio chunks delivered as they generate

• 📦 Batch Processing - Process multiple texts in one request

• 🤖 MCP Server - AI agent integration (Claude, etc.)

• 🌍 Multi-language - English, Chinese, Japanese, Spanish, French, Hindi, Italian, Portuguese

• 🚀 GPU Accelerated - CUDA support with automatic memory management

• 📱 54+ Voices - Wide variety of male and female voices

Related MCP server: Open AI Text To Speech1 MCP Server

🚀 Quick Start

docker run -d --name kokoro-tts --gpus all -p 8300:8300 neosun/kokoro-tts:latest

Open http://localhost:8300 in your browser.

📦 Installation

Prerequisites

• Docker 20.10+

• NVIDIA GPU with CUDA support (optional, CPU fallback available)

• nvidia-docker2 (for GPU support)

Docker Run

# With GPU
docker run -d \
  --name kokoro-tts \
  --gpus all \
  -p 8300:8300 \
  -e GPU_IDLE_TIMEOUT=600 \
  --restart unless-stopped \
  neosun/kokoro-tts:latest

# CPU only
docker run -d \
  --name kokoro-tts \
  -p 8300:8300 \
  --restart unless-stopped \
  neosun/kokoro-tts:latest

Docker Compose

services:
  kokoro-tts:
    image: neosun/kokoro-tts:latest
    container_name: kokoro-tts
    ports:
      - "8300:8300"
    environment:
      - GPU_IDLE_TIMEOUT=600
      - KEEP_MODEL_LOADED=true  # Never release model from memory
    deploy:
      resources:
        reservations:
          devices:
            - driver: nvidia
              count: 1
              capabilities: [gpu]
    restart: unless-stopped

docker-compose up -d

Verify Installation

# Health check
curl http://localhost:8300/health

# Generate speech
curl -X POST http://localhost:8300/api/tts \
  -H "Content-Type: application/json" \
  -d '{"text":"Hello world","voice":"af_heart"}' \
  -o output.wav

⚙️ Configuration

📖 Usage

Web UI

REST API

Generate Speech (WAV)

curl -X POST http://localhost:8300/api/tts \
  -H "Content-Type: application/json" \
  -d '{"text":"Hello world","voice":"af_heart","speed":1.0}' \
  -o output.wav

Generate Speech (Base64)

curl -X POST http://localhost:8300/api/tts/base64 \
  -H "Content-Type: application/json" \
  -d '{"text":"Hello world","voice":"af_heart","speed":1.0}'

Streaming

curl -X POST http://localhost:8300/api/tts/stream \
  -H "Content-Type: application/json" \
  -d '{"text":"Long text here...","voice":"af_heart"}'

Batch Processing

curl -X POST http://localhost:8300/api/tts/batch \
  -H "Content-Type: application/json" \
  -d '{
    "items": [
      {"id":"1","text":"First","voice":"af_heart"},
      {"id":"2","text":"Second","voice":"am_michael"}
    ]
  }'

WebSocket

const ws = new WebSocket('ws://localhost:8300/ws/tts');
ws.onopen = () => {
  ws.send(JSON.stringify({
    text: "Hello world",
    voice: "af_heart",
    speed: 1.0
  }));
};
ws.onmessage = (e) => {
  const data = JSON.parse(e.data);
  if (data.status === 'chunk') {
    // Play audio: data.audio (base64)
  }
};

MCP Integration

{
  "mcpServers": {
    "kokoro-tts": {
      "command": "docker",
      "args": ["exec", "-i", "kokoro-tts", "python", "/app/docker/server.py", "mcp"]
    }
  }
}

🎤 Available Voices

Models

Voice Examples

📚 API Documentation

• Swagger UI: http://localhost:8300/docs

• ReDoc: http://localhost:8300/redoc

🏗️ Project Structure

kokoro/
├── docker/
│   ├── server.py        # FastAPI server
│   ├── ui_template.py   # Web UI
│   └── mcp_server.py    # MCP tools
├── kokoro/              # Core TTS library
├── Dockerfile
├── docker-compose.yml
└── README.md

🛠️ Tech Stack

• Backend: FastAPI, Uvicorn

• TTS Engine: Kokoro-82M (StyleTTS 2)

• Deep Learning: PyTorch, CUDA

• Container: Docker, NVIDIA Container Toolkit

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the repository

2. Create your feature branch (git checkout -b feature/amazing)

3. Commit your changes (git commit -m 'Add amazing feature')

4. Push to the branch (git push origin feature/amazing)

5. Open a Pull Request

📖 Documentation

• Streaming Optimization Guide - How we reduced latency from 2s to 50ms

📝 Changelog

v1.1.1 (2025-01) - 🔒 Keep Model Loaded

🆕 New Features

• Added KEEP_MODEL_LOADED environment variable

• When set to true, model stays in GPU memory permanently

• Eliminates cold start delay completely for consistent 51ms TTFB

📊 Latest Performance (2025-01-29)

• Local TTFB: 51-53ms (stable)

• Cloudflare TTFB: 138-178ms

• First chunk: 54ms, 71.5KB

v1.1.0 (2025-01) - 🚀 Streaming Latency Optimization

⚡ Major Performance Improvements

• 40x faster first play - Reduced from 2s+ to ~50ms

• 6x smaller first chunk - Reduced from 436KB to 71.5KB

• 10x faster TTFB - Reduced from ~500ms to ~50ms (local)

🔧 Backend Optimizations

• Split audio by sentence/clause ([.!?。！？,，;；:：]+) instead of newline

• Model warmup on startup - eliminates cold start delay (93ms → 56ms)

• Added X-Accel-Buffering: no and Cache-Control: no-cache headers

• Streaming chunks now generated per sentence for immediate delivery

🎨 Frontend Optimizations

• Non-blocking audio decoding with .then() instead of await

• AudioContext auto-resume for browser autoplay policy

• Immediate playback when first chunk decoded

• Parallel chunk receiving and audio decoding

📊 Performance Metrics Panel (Stream tab)

• Time to First Byte (TTFB) - measures server response time

• Time to First Play - measures actual audio start time

• Total Time - real-time elapsed time counter

• Data Size - total bytes received

🎛️ UI Enhancements

• Added Model selector to Stream, WebSocket, Batch tabs

• Added Voice selector to Stream, WebSocket, Batch tabs

• Added Speed slider to Stream, WebSocket, Batch tabs

• Real-time metrics update during streaming

• Improved status indicators and toast notifications

🐛 Bug Fixes

• Fixed WebSocket sendWS() using wrong model selector

• Fixed Batch tab missing audio playback controls

• Fixed version number display in UI footer

v1.0.0 (2025-01) - 🎉 Initial Release

✨ Core Features

• Beautiful Web UI with 4 tabs (Single, Stream, WebSocket, Batch)

• Full-featured REST API with Swagger/ReDoc documentation

• WebSocket real-time bidirectional TTS

• Streaming audio delivery as chunks generate

• Batch processing for multiple texts

🤖 AI Integration

• MCP Server for AI agent integration (Claude, Cursor, etc.)

• Tool-based TTS generation for AI workflows

🌍 Multi-language Support

• 9 languages: English, Chinese, Japanese, Spanish, French, Hindi, Italian, Portuguese, Korean

• 54+ voices with male and female options

• Multi-model support: Kokoro-82M (general) and Kokoro-82M-v1.1-zh (Chinese optimized)

🚀 Infrastructure

• GPU accelerated with CUDA support

• Automatic GPU memory management with configurable idle timeout

• CPU fallback when GPU unavailable

• Docker containerized deployment

v1.0.0 (2025-01) - 🎉 Initial Release

✨ Core Features

• Beautiful Web UI with 4 tabs (Single, Stream, WebSocket, Batch)

• Full-featured REST API with Swagger/ReDoc documentation

• WebSocket real-time bidirectional TTS

• Streaming audio delivery as chunks generate

• Batch processing for multiple texts

🤖 AI Integration

• MCP Server for AI agent integration (Claude, Cursor, etc.)

• Tool-based TTS generation for AI workflows

🌍 Multi-language Support

• 9 languages: English, Chinese, Japanese, Spanish, French, Hindi, Italian, Portuguese, Korean

• 54+ voices with male and female options

• Multi-model support: Kokoro-82M (general) and Kokoro-82M-v1.1-zh (Chinese optimized)

🚀 Infrastructure

• GPU accelerated with CUDA support

• Automatic GPU memory management with configurable idle timeout

• CPU fallback when GPU unavailable

• Docker containerized deployment

📄 License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.

🙏 Acknowledgements

• hexgrad/Kokoro-82M - The amazing TTS model

• StyleTTS 2 - Model architecture

⭐ Star History

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