voice-transcriber-mcp 2.1.0

MCP server for transcribing Google Chat voice messages using Groq Whisper API

Voice Transcriber MCP Server

MCP server that automatically transcribes Google Chat voice messages using Groq Whisper API (whisper-large-v3). No local GPU needed.

When Claude Code encounters an audio attachment in a Google Chat message, this server transcribes it immediately without asking for confirmation.

Features

• Transcribe Google Chat voice messages by URL (automatic)
• Transcribe local audio files (mp3, m4a, wav, ogg, flac, webm, aac)
• Uses Groq Whisper API (free tier, fast, cloud-based)
• Reuses Google Chat OAuth2 credentials (no separate Google auth needed)

Prerequisites

1. Groq API Key (free)

1. Go to console.groq.com/keys
2. Create a free account
3. Generate an API key
4. You'll set this as GROQ_API_KEY in your MCP config (see below)

2. Google Chat OAuth2 Token

This server needs a valid Google Chat OAuth2 token (token.json) to fetch messages and download audio attachments.

If you already use a Google Chat MCP server (e.g. multi-chat-mcp-server), the token is already available. Default path:

~/tools/multi-chat-mcp-server/src/providers/google_chat/token.json

If your token is in a different location, set the GCHAT_TOKEN_PATH environment variable.

If you don't have a Google Chat token yet, you need to:

1. Create a Google Cloud project with Chat API enabled
2. Create OAuth2 credentials (Desktop app)
3. Run the OAuth flow to generate token.json with scopes:
   • https://www.googleapis.com/auth/chat.messages.readonly
   • https://www.googleapis.com/auth/chat.spaces.readonly

3. uv (Python package manager)

OS	Command
Linux / macOS / WSL	curl -LsSf https://astral.sh/uv/install.sh | sh
Windows	powershell -c "irm https://astral.sh/uv/install.ps1 | iex"

Verify: uv --version

Installation

git clone https://github.com/fgasparetto/voice-transcriber-mcp.git
cd voice-transcriber-mcp
uv sync

Configuration

Add to your Claude Code MCP config (.mcp.json or ~/.claude.json):

{
  "mcpServers": {
    "voice-transcriber": {
      "type": "stdio",
      "command": "uv",
      "args": [
        "--directory", "/path/to/voice-transcriber-mcp",
        "run", "python", "server.py"
      ],
      "env": {
        "GROQ_API_KEY": "gsk_your_groq_api_key_here"
      }
    }
  }
}

Replace:

• /path/to/voice-transcriber-mcp with the actual clone directory
• gsk_your_groq_api_key_here with your Groq API key

Environment Variables

Variable	Required	Default	Description
GROQ_API_KEY	Yes	—	Groq API key (get one free)
GCHAT_TOKEN_PATH	No	~/tools/multi-chat-mcp-server/src/providers/google_chat/token.json	Path to Google Chat OAuth2 token

Tools

transcribe_voice_message

Transcribe a voice message from Google Chat. Called automatically by Claude when it encounters an audio attachment.

transcribe_voice_message(
  message_url="https://chat.google.com/dm/SPACE/THREAD/MSG",
  language="it"
)

transcribe_audio_file

Transcribe a local audio file.

transcribe_audio_file(
  file_path="/tmp/recording.m4a",
  language="it"
)

Platform Notes

Linux

No additional steps. Ensure uv is in your PATH.

macOS

• If uv not found after install: export PATH="$HOME/.local/bin:$PATH"

Windows (WSL)

Claude Code runs inside WSL. All paths must be Linux-style:

• Token path: /home/USER/tools/... (NOT /mnt/c/...)
• If uv not found: source ~/.bashrc or add ~/.local/bin to PATH

Troubleshooting

Problem	Solution
GROQ_API_KEY not set	Add it to the env section in your MCP config
Google Chat token not found	Set GCHAT_TOKEN_PATH or authenticate your Google Chat MCP
Groq API error 413	Audio file too large (Groq limit: 25MB)
uv: command not found	Install uv (see Prerequisites)

How It Works

Claude Code → MCP tool call → server.py
  1. Parse Google Chat URL
  2. Fetch message via Google Chat API (OAuth2 token)
  3. Download audio attachment via media API
  4. Send to Groq Whisper API (whisper-large-v3)
  5. Return transcribed text

License

MIT