Garmin Messenger Plugin for OpenClaw

Channel plugin that connects OpenClaw to Garmin Messenger (Hermes) — let your AI agent send and receive satellite messages.

Built on the Go CLI via MCP stdio.

Quick Start

# 1. Install the plugin
openclaw plugins install @slush-openclaw/garmin-messenger

# 2. Add and authenticate (interactive wizard)
openclaw channels add
# Select "Garmin Messenger" from the list — the wizard handles SMS login automatically.

To install a specific version:

openclaw plugins install @slush-openclaw/[email protected]

curl -LO https://github.com/slush-dev/garmin-messenger/releases/latest/download/garmin-messenger-openclaw-plugin.tgz
openclaw plugins install ./garmin-messenger-openclaw-plugin.tgz

The postinstall script downloads the garmin-messenger binary for your platform from the same GitHub release.

Authentication

Interactive wizard (recommended)

openclaw channels add

Select Garmin Messenger from the channel list. The wizard prompts for your phone number, sends an SMS verification code, and saves the session.

Note: openclaw channels add --channel garmin-messenger uses the non-interactive path — it enables the channel in config but does not start the login wizard. Use the bare openclaw channels add for the full setup experience.

Re-login

openclaw channels login --channel garmin-messenger

Prompts for phone number and SMS code via stdin.

Agent-driven login

If the channel is enabled but not logged in, the AI agent can authenticate during conversation using the garmin_login tool. The agent will ask for your phone number and SMS code.

Non-interactive (flags only)

openclaw channels add --channel garmin-messenger --auth-dir ~/.garmin-messenger --cli-path /usr/bin/garmin-messenger

Enables the channel without logging in. Authenticate afterwards with openclaw channels login or let the agent handle it.

Configuration

| Option | Type | Default | Description | |--------|------|---------|-------------| | binaryPath | string | auto-detect | Path to garmin-messenger binary | | sessionDir | string | ~/.garmin-messenger | Directory for saved credentials | | verbose | boolean | false | Enable debug logging for the MCP binary | | dmPolicy | string | pairing | DM policy: open, pairing, or allowlist | | allowFrom | string[] | — | Phone numbers allowed to send messages (allowlist policy) |

DM Policies

• open — accept messages from anyone
• pairing — accept messages from existing conversations
• allowlist — only accept messages from numbers in allowFrom

How It Works

The plugin spawns the garmin-messenger mcp binary as a subprocess and communicates via MCP (Model Context Protocol) over stdio:

1. Outbound — OpenClaw calls send_message / send_media_message MCP tools
2. Inbound — the MCP server pushes notifications/resources/updated when new messages arrive via FCM
3. Binary resolution — checks config path, then bundled bin/ directory (populated by postinstall), then PATH

Development

cd apps/openclaw-plugin

# Install dependencies
npm install --ignore-scripts

# Run tests
npm test

# Run tests in watch mode
npm run test:watch

# Build tarball
make build-openclaw-plugin    # outputs build/openclaw-plugin/*.tgz

Project Structure

| File | Purpose | |------|---------| | index.ts | Plugin entry point — register(api) | | src/channel.ts | Channel plugin implementation (gateway, outbound, security, directory, setup, auth) | | src/onboarding.ts | Interactive onboarding wizard for openclaw channels add | | src/agent-tools.ts | garmin_login agent tool for LLM-driven authentication | | src/mcp-bridge.ts | MCP client wrapper for the Go binary | | src/binary.ts | Binary resolution (config / bundled / PATH) | | src/platform.ts | Shared platform constants and helpers | | src/postinstall.ts | Downloads platform binary from GitHub Releases | | src/types.ts | TypeScript type definitions | | openclaw.plugin.json | Plugin manifest for OpenClaw |