Graindrop

Audio capture pipeline. Listens for audio files, transcribes via whisper.cpp, and serves audio + transcript through an MCP server.

Audio file → graindrop → whisper.cpp → manifest.json → MCP server (:8648)

Any MCP-compatible agent (Hermes, Claude Code, Cursor, etc.) connects to the graindrop MCP and discovers new recordings as they land.

One-sentence pitch

A self-contained daemon that watches a directory, transcribes anything that lands in it, and presents the results to any AI agent through a standard protocol — no cloud, no subscriptions, no vendor lock-in.

How it works

1. Drop an audio file (.m4a, .wav, .mp3) into the watched directory
2. graindrop copies it to audio/, transcribes via whisper.cpp to transcripts/, archives the original to _archive/, and logs it in manifest.json
3. The MCP server exposes the recording to any connected agent through tools and resources
4. The agent reads the transcript, fetches the audio, and does what it does

Quick start

# Install
pip install graindrop
# or from source:
git clone https://github.com/stuartmhannon/graindrop
cd graindrop
pip install -e .

# Start the MCP server
graindrop-mcp --port 8648

# The server watches ~/Dropbox/graindrop/ by default
# Drop an .m4a in there and the MCP server picks it up

MCP Tools

Tool	Purpose
graindrop_list	List all recordings, newest first
graindrop_list_unread	List only unacknowledged recordings
graindrop_get_transcript	Full transcript text for a recording
graindrop_get_audio	Audio file path for a recording
graindrop_ack	Mark a recording as read
graindrop_stats	Summary counts

MCP Resources

URI	Content
graindrop://recording/{id}/transcript	Plain text transcript
graindrop://recording/{id}/audio	Binary audio (m4a/wav)

Configuration

graindrop-mcp --port 8648 --dir ~/grain/reference/graindrop

• --port: HTTP SSE port (default: 8648)
• --dir: Data directory (default: ~/grain/reference/graindrop)

The watched directory defaults to ~/Dropbox/graindrop/. Override by editing WATCH_DIR in graindrop_mcp.py.

Storage layout

~/grain/reference/graindrop/
├── audio/{slug}.{ext}       ← canonical audio copy
├── transcripts/{slug}.txt   ← whisper transcript
├── _archive/{original}      ← source file backup
├── manifest.json            ← searchable index
├── graindrop_mcp.py         ← MCP server
├── graindrop_watcher.py     ← processing script

Requirements

• Python 3.10+
• whisper.cpp (for transcription)
• ffmpeg (for audio conversion)
• mcp[cli] (installed automatically)

Agent integration

Hermes Agent

Add to ~/.hermes/config.yaml:

mcp_servers:
  graindrop:
    url: http://127.0.0.1:8648/sse
    transport: sse

Any MCP client

Connect to http://127.0.0.1:8648/sse using the MCP protocol's HTTP SSE transport. Call tools/list to discover available tools, then tools/call to invoke them.

License

MIT — do what you want, just don't blame us.