@squirrelsoft/dev-say

An MCP (Model Context Protocol) server that provides text-to-speech functionality using the macOS say command. This allows Claude Code running in a devcontainer to trigger speech synthesis on your Mac host.

Features

• Convert text to speech using macOS native say command
• Choose from available system voices
• Adjust speech rate
• Save audio to file (AIFF format)
• Works seamlessly with Claude Code in devcontainers

Prerequisites

• macOS (required - uses the native say command)
• Node.js 16+
• npm or yarn

Installation

Global Installation via npm

npm install -g @squirrelsoft/dev-say

Local Installation from Source

1. Clone this repository on your Mac host:

git clone https://github.com/sbeardsley/dev-say.git
cd dev-say

2. Install dependencies:

npm install

3. Build the TypeScript code:

npm run build

4. Link globally (optional):

npm link

Quick Start

After installing globally with npm, you can manage the server with these simple commands:

# Start the server (runs in background on port 8837)
dev-say start

# Stop the server
dev-say stop

# Check if server is running
dev-say status

# Restart the server
dev-say restart

# View server logs
dev-say logs

The server will run in the background and automatically log to ~/.dev-say.log.

Usage

Running the Server

Using the CLI (Recommended)

Once installed globally via npm install -g @squirrelsoft/dev-say:

# Start the server in the background
dev-say start

# Stop the server
dev-say stop

# Check server status
dev-say status

# Restart the server
dev-say restart

# View logs
dev-say logs

Manual Mode

The server supports two transport modes:

HTTP Mode (for Devcontainer/Remote Access)

# Default mode - runs HTTP server on port 8837
npm start

# Or explicitly set HTTP mode
MCP_TRANSPORT=http PORT=8837 npm start

Stdio Mode (Legacy)

MCP_TRANSPORT=stdio npm start

For development with hot reload:

npm run dev

Configuration

For Claude Code in Devcontainer

1. Start the server on your Mac host:

If installed globally:

dev-say start

Or manually:

cd /path/to/dev-say
npm install
npm run build
npm start  # Runs HTTP server on port 8837

2. Configure Claude Code inside the devcontainer:

Use the Claude Code CLI to add the MCP server:

claude mcp add --transport http dev-say http://host.docker.internal:8837/mcp

Alternatively, you can manually add to your MCP settings (typically ~/.config/claude/settings.json in the container):

{
  "mcpServers": {
    "dev-say": {
      "url": "http://host.docker.internal:8837/mcp",
      "transport": "http"
    }
  }
}

Important: The server uses the MCP Streamable HTTP transport which requires:

• Proper Accept headers (application/json, text/event-stream)
• Session management via Mcp-Session-Id header
• Initialize request to start a session

Claude Code should handle this automatically when configured with "transport": "http".

The host.docker.internal hostname automatically resolves to your Mac host from within the Docker container.

For Local Claude Code on Mac

1. Start the server on your Mac:

If installed globally:

dev-say start

Or manually:

cd /path/to/dev-say
npm install
npm run build
npm start  # Runs HTTP server on port 8837

2. Configure Claude Code:

Use the Claude Code CLI to add the MCP server:

claude mcp add --transport http dev-say http://localhost:8837/mcp

Alternatively, you can manually add to your Claude Code MCP settings (~/Library/Application Support/Claude/claude_code_config.json):

{
  "mcpServers": {
    "dev-say": {
      "url": "http://localhost:8837/mcp",
      "transport": "http"
    }
  }
}

Available Tools

The server exposes a single speak tool with the following parameters:

• text (required): The text to speak
• voice (optional): The voice to use (run say -v ? in terminal to see available voices)
• rate (optional): Speech rate in words per minute (default: 175)
• outputFile (optional): Path to save audio file instead of playing

Example Usage in Claude Code

Once configured, you can use the speak tool in Claude Code:

Use the speak tool to say "Hello, world!"

With options:

Use the speak tool to say "Hello" with voice "Samantha" at rate 200

Save to file:

Use the speak tool to save "This is a test" to output.aiff

Available Voices

To see all available voices on your system, run:

say -v ?

Popular voices include:

• Alex (US English)
• Samantha (US English)
• Daniel (British English)
• Karen (Australian English)
• Tessa (South African English)

Troubleshooting

Devcontainer Connection Issues

Server not accessible from container

• Ensure the server is running on your Mac: npm start
• Check the server is listening on all interfaces: should show 0.0.0.0:8837
• Test connectivity from container: curl http://host.docker.internal:8837/health
• Verify Docker Desktop settings allow host networking

MCP configuration not working

• Check Claude Code settings location in your container
• Verify the curl command can reach the server
• Look for error messages in Claude Code logs

General Issues

Server not connecting

• Ensure the path in your MCP config is absolute and correct
• Check that the server builds successfully with npm run build
• Verify Node.js is in your PATH

No sound output

• Check your Mac's volume settings
• Ensure the say command works in terminal: say "test"
• Verify you're running on macOS (not Linux/Windows)

Voice not found

• Use say -v ? to list available voices
• Voice names are case-sensitive

Testing the Server

Test HTTP endpoint directly:

# From your Mac
curl -X POST http://localhost:8837/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"tools/list","params":{},"id":1}'

# From devcontainer
curl -X POST http://host.docker.internal:8837/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"tools/list","params":{},"id":1}'

Test health endpoint:

curl http://localhost:8837/health

Development

Project Structure

dev-say/
├── bin/
│   └── cli.js          # CLI commands (start/stop/status)
├── src/
│   └── server.ts       # MCP server implementation
├── dist/               # Compiled JavaScript (generated)
├── package.json        # Dependencies and scripts
├── tsconfig.json       # TypeScript configuration
└── README.md          # This file

Building

npm run build

Testing Locally

You can test the say command directly:

say "Hello, world!"
say -v Samantha "Hello"
say -r 300 "Fast speech"
say -o output.aiff "Save to file"

License

MIT