Chatterbox TTS MCP Server

A simplified Model Context Protocol (MCP) server that provides text-to-speech generation with automatic playback using the Chatterbox TTS model. The server loads the model automatically on first use and provides real-time progress notifications to keep users informed throughout the process.

Overview

This MCP server exposes Chatterbox TTS functionality through a single, streamlined tool that generates speech from text and plays it automatically. The server handles model loading, progress reporting, temporary file management, and audio playback seamlessly.

Features

Single Tool: speak_text

The speak_text tool provides complete text-to-speech functionality:

• Parameters:

  • text (required): The text to convert to speech
  • exaggeration (optional): Controls expressiveness (0.0-1.0, default 0.5)
  • cfg_weight (optional): Controls classifier-free guidance (0.0-1.0, default 0.5)

• Features:

  • Automatic model loading with progress notifications
  • Generates speech using temporary files (auto-cleanup)
  • Plays audio automatically on macOS using afplay
  • Real-time progress updates during all phases:
    • Model initialization and loading
    • Speech generation
    • Audio playback

Resource: chatterbox://model-info

Get information about the TTS model status and device capabilities:

• Model loading status (loaded/not loaded)
• Device information (MPS/CUDA/CPU)
• Hardware acceleration availability

Progress Notifications

The server provides detailed progress notifications throughout the speech generation process:

1. Model Loading Phase:

   • "Loading Chatterbox TTS model..."
   • "Initializing PyTorch device..."
   • "Loading model weights..."
   • "Model loaded successfully!"

2. Speech Generation Phase:

   • "Starting speech generation..."
   • "Speech generated, saving to temporary file..."

3. Playback Phase:

   • "Playing audio..."
   • "Audio playback completed!"

4. Status Updates:

   • Device selection (MPS/CUDA/CPU)
   • Voice prompt usage when applicable
   • Success/error messages

Installation

1. Install dependencies:

   pip install mcp torch torchaudio
   

2. Install Chatterbox TTS: Follow the Chatterbox TTS installation instructions to ensure the chatterbox.tts module is available.

Configuration

Audio File Storage

By default, the server stores audio files in ~/.chatterbox/audio. You can configure a custom location using:

Command line argument:

python chatterbox_mcp_server.py --audio-dir /path/to/custom/audio/directory

Environment variable:

export CHATTERBOX_AUDIO_DIR="/path/to/custom/audio/directory"
python chatterbox_mcp_server.py

Priority order:

1. Command line --audio-dir argument (highest priority)
2. CHATTERBOX_AUDIO_DIR environment variable
3. Default: ~/.chatterbox/audio (lowest priority)

Audio File TTL (Time To Live)

By default, audio files are automatically cleaned up after 1 hour. You can configure a custom TTL:

Command line argument:

python chatterbox_mcp_server.py --audio-ttl-hours 24  # Keep files for 24 hours

Environment variable:

export CHATTERBOX_AUDIO_TTL_HOURS=24
python chatterbox_mcp_server.py

Priority order:

1. Command line --audio-ttl-hours argument (highest priority)
2. CHATTERBOX_AUDIO_TTL_HOURS environment variable
3. Default: 1 hour (lowest priority)

Model Auto-Loading

By default, the TTS model is loaded on first use to minimize startup time. You can pre-load it at startup:

Command line argument:

python chatterbox_mcp_server.py --auto-load-model

This will load the model during server startup, which takes a few seconds but ensures the first TTS request is faster.

Audio Storage Features:

• Audio files are stored persistently with configurable automatic cleanup
• Files are accessible via chatterbox://audio/{resource_id} resources
• Directory is created automatically if it doesn't exist
• Supports relative paths (will be expanded) and ~ home directory notation

Usage

Running the Server

Standalone:

python chatterbox_mcp_server.py

With MCP tools:

mcp dev chatterbox_mcp_server.py

Integration with Claude Desktop

Add to your Claude Desktop MCP configuration:

Basic configuration:

{
  "mcpServers": {
    "chatterbox-tts": {
      "command": "python",
      "args": ["/path/to/chatterbox_mcp_server.py"],
      "env": {}
    }
  }
}

With custom configuration:

{
  "mcpServers": {
    "chatterbox-tts": {
      "command": "python",
      "args": [
        "/path/to/chatterbox_mcp_server.py", 
        "--audio-dir", "/custom/audio/path",
        "--auto-load-model",
        "--audio-ttl-hours", "24"
      ],
      "env": {
        "CHATTERBOX_AUDIO_DIR": "/custom/audio/path",
        "CHATTERBOX_AUDIO_TTL_HOURS": "24"
      }
    }
  }
}

Example Usage from LLM

1. Basic text-to-speech:

   Please use the speak_text tool to say "Hello, welcome to the Chatterbox TTS demonstration!"
   

2. Expressive speech:

   Use speak_text to generate enthusiastic speech for "This is amazing!" with high expressiveness
   

The tool will automatically:

• Load the model if needed (with progress updates)
• Generate the speech
• Play the audio
• Clean up temporary files
• Provide status updates throughout

Technical Details

Device Support

• Apple Silicon (M1/M2/M3/M4): Uses MPS acceleration when available
• NVIDIA GPUs: Uses CUDA when available
• CPU fallback: Works on any system

Audio Processing

• Uses temporary files for audio storage
• Automatic cleanup after playback
• WAV format output
• High-quality audio generation

Model Management

• Model loads once on first use
• Shared across all subsequent requests
• Thread-safe loading with progress tracking
• Automatic device detection and optimization

File Structure

chatterbox-mcp/
├── chatterbox_mcp_server.py    # MCP server implementation
└── README.md                   # This documentation

Development

Key Improvements in This Version

1. Simplified Interface: Single speak_text tool instead of multiple tools
2. Automatic Playback: No need to manually play generated files
3. Progress Notifications: Real-time updates on model loading and generation
4. Persistent Audio Storage: Audio files are stored with configurable automatic cleanup
5. Better Error Handling: Comprehensive error reporting and recovery
6. Streamlined Workflow: One command generates and plays speech

Troubleshooting

Common Issues:

1. Model loading slow:

   • First-time loading downloads model weights
   • Progress notifications show current status
   • Subsequent uses are much faster

2. Audio playback issues:

   • afplay command is macOS-specific
   • Ensure system audio is working
   • Check volume settings

3. Memory issues:

   • Model requires significant GPU/CPU memory
   • Monitor system resources during loading
   • Consider closing other applications

4. Device selection:

   • Server automatically selects best available device
   • Check model info resource for current device
   • MPS (Apple Silicon) > CUDA (NVIDIA) > CPU

License

This MCP server implementation follows the same license as the underlying Chatterbox TTS model.