macwhisper-mcp-server

Local MCP server that connects MacWhisper to Claude Desktop.

What it does: Drop an audio file on your Desktop, then ask Claude to transcribe it, summarise it, or pull out action items — in one step. MacWhisper does the transcription on your Mac; Claude does the thinking. Nothing leaves your machine. No cloud APIs. No data ever leaves your Mac.

Audio file  →  MacWhisper CLI  →  MCP server  →  Claude Desktop

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Requirements

• macOS (MacWhisper is macOS-only)
• MacWhisper — installed and licensed
• MacWhisper CLI enabled: open MacWhisper → Settings → Advanced → Command-Line Tool → Install. This places mw at /usr/local/bin/mw.
• Python 3.13.x via pyenv
• Claude Desktop

Installing MacWhisper via Homebrew:

brew install --cask macwhisper

After installation, enable the CLI in MacWhisper Settings as above. When you later run brew upgrade --cask macwhisper, the CLI symlink updates automatically — no re-install needed.

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Install

git clone https://github.com/docdyhr/macwhisper-mcp-server.git
cd macwhisper-mcp-server

pyenv install 3.13.13   # skip if already installed
pyenv local 3.13.13
python -m venv .venv
source .venv/bin/activate
pip install -e .

Verify the MacWhisper CLI is reachable:

mw version

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Configure Claude Desktop

Edit ~/Library/Application Support/Claude/claude_desktop_config.json and add:

{
  "mcpServers": {
    "macwhisper": {
      "command": "/Users/<you>/macwhisper-mcp-server/.venv/bin/macwhisper-mcp",
      "args": [],
      "env": {
        "MACWHISPER_ALLOWED_PATHS": "/Users/<you>/Desktop:/Users/<you>/Downloads",
        "FASTMCP_CHECK_FOR_UPDATES": "off"
      }
    }
  }
}

Replace <you> with your macOS username. Restart Claude Desktop.

Note: Audio files must be saved to your Mac's filesystem (Desktop, Downloads, or another allow-listed folder) before asking Claude to transcribe them. Files uploaded directly to the Claude chat window live in Claude's container and are not accessible to the local MacWhisper CLI.

Verify it works

In Claude Desktop, ask:

Transcribe ~/Desktop/memo.m4a

You should see a transcribe_audio tool call appear, followed by the transcript.

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Available tools

Tool	Description
transcribe_audio(path, model?, persist?)	Transcribe an audio file and return the transcript as plain text. Pass persist=true to save to MacWhisper history.
list_models()	List transcription models installed in MacWhisper; active model is marked
cancel_transcription()	Cancel the currently running transcription
list_allowed_paths()	Return the directories the server is allowed to read from
start_watch(folder)	Watch a folder and auto-transcribe new audio files into ../done/
stop_watch()	Stop the active folder watcher
get_watch_results()	Return completed watch-folder transcriptions and clear the queue

Supported audio formats: .m4a .mp3 .mp4 .mov .wav .aiff .flac

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Configuration

All configuration is via environment variables. Pass them through the env dict in claude_desktop_config.json (for Claude Desktop) or set them in .env for local development.

Env var	Default	Description
MACWHISPER_ALLOWED_PATHS	~/Desktop	Colon-separated list of directories the server may read from
MACWHISPER_CLI	auto-detected	Path to the mw binary. Defaults to /Applications/MacWhisper.app/Contents/MacOS/mw if that file exists, otherwise mw on PATH
MACWHISPER_LOG_PATH	~/Library/Logs/macwhisper-mcp.log	Log file path (never stdout — that's reserved for MCP)

Local development: copy .env.example to .env and adjust. With direnv, .envrc exports .env automatically. Without direnv: source .env.

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Development

source .venv/bin/activate
pip install -e ".[dev]"

# Tests
pytest -q

# Lint + format
ruff check .
ruff format .

# Pre-commit hooks (one-time setup)
pip install pre-commit
pre-commit install

# Smoke-test against a real audio file (server must not be running in Claude Desktop)
python scripts/smoke_test.py ~/Downloads/Test.m4a

Logs

tail -f ~/Library/Logs/macwhisper-mcp.log

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Security

• All file paths are resolved (symlinks followed) and checked against the MACWHISPER_ALLOWED_PATHS allow-list before anything reaches the CLI.
• subprocess.run is always called with an argv list — never shell=True.
• No network calls. Ever.

See PRD §7 for the full threat model.

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Known limitations

• Uploaded files: Files dragged into the Claude chat window live in Claude's container and are not accessible to the local MacWhisper CLI. Save the file to your Desktop or Downloads folder (or another allow-listed directory), then ask Claude to transcribe it from there.
• Danish letter names: Whisper may phonetically approximate letter names (e.g. "Æ, Ø, Å" → "E, Y, U") when they are spoken in isolation. Letters inside words transcribe correctly. This is a Whisper engine limitation, not a bug in this wrapper. See PRD §12.
• Cold-start latency: First transcription after MacWhisper launches takes ~13s (model load). Subsequent calls are ~2s.

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License

MIT — see LICENSE.