Garmin MCP Worker

Ask Claude about your own Garmin data — from your phone or your desktop.

A read-only remote MCP server that connects Claude (or any MCP client with remote OAuth support) to your Garmin Connect account through Garmin's official Personal API. It runs on Cloudflare Workers' free tier and signs you in with OAuth, so it works in the Claude mobile app, not just on a desktop.

中文说明

"Should I do intervals today?" · "How has my HRV trended this month?" · "Compare my last three long runs." · "Did short sleep hurt my next-day runs?"

Why this one

• Stable: Garmin's documented Personal API with a revocable key. No password, no scraping.

• Free: fits comfortably in Cloudflare's free tier.

• Model-friendly: compact rows, long ranges split for you, bulky sample arrays left out unless asked.

• Current protocol: speaks MCP 2026-07-28 (stateless, server/discover) and 2025-03-26 … 2025-11-25.

Related MCP server: garmin-connect-mcp-server

Tools

All tools are annotated readOnlyHint: true.

Deploy

You need a free Cloudflare account and a Garmin Personal API key: sign in to Garmin Connect on the web, open Settings → Personal API, choose Create Key and copy it (it's shown once; pick up to a year of validity).

Option A — one click

Press Deploy to Cloudflare above. Cloudflare copies the repo to your GitHub account, creates the KV namespace, and asks for:

• GARMIN_API_KEY — your Personal API key

• LOGIN_PASSWORD — a long password you'll type when connecting Claude

• TIMEZONE — e.g. Europe/London (used for "today")

Option B — command line

Requires Node.js 20+.

git clone https://github.com/wesleysui/garmin-mcp-worker && cd garmin-mcp-worker
npm install
npx wrangler login
npx wrangler secret put GARMIN_API_KEY
npx wrangler secret put LOGIN_PASSWORD
npm run deploy            # the KV namespace is created automatically

Set your time zone in wrangler.jsonc (vars.TIMEZONE) before deploying.

Connect Claude

1. In Claude (web), open the connector settings and choose Add custom connector.

2. URL: https://garmin-mcp.<your-subdomain>.workers.dev/mcp

3. Press Connect, enter your LOGIN_PASSWORD on the sign-in page, choose Allow.

4. Enable the connector in a chat. Connectors added on the web also appear in the mobile apps.

Other MCP clients that support remote servers with OAuth work the same way.

What the Personal API doesn't have

• Training Readiness, Training Status, race predictions — not exposed. Use garmin_get_recovery_trend and let the model reason from HRV, sleep and resting HR instead.

• VO2max — Garmin currently strips it from API data; read it from your watch.

• Writing anything — the API is read-only, so no pushing workouts or courses to the watch.

• Push notifications — data is pulled on request; new activities appear after your watch syncs.

Security

• OAuth 2.1 with PKCE via Cloudflare's workers-oauth-provider; tokens are stored only as hashes.

• The consent page shows which app is asking and where tokens go, can't be framed, and uses a one-time, browser-bound form.

• One owner password, compared in constant time; 5 wrong attempts lock sign-in for 15 minutes.

• The Garmin key lives only in Worker secrets and never appears in responses or logs.

• Only GET requests ever reach Garmin; the token endpoint is blocked from the raw reader.

Found a problem? Please open a private security advisory rather than a public issue.

Maintenance

• Key expiry: Garmin emails you about a week before. Create a new key and run npx wrangler secret put GARMIN_API_KEY — no need to reconnect Claude.

• Staying signed in: Claude refreshes its access automatically; after 30 idle days you'll be asked for the password again.

• Logs: npx wrangler tail

Development

npm install
cp .dev.vars.example .dev.vars   # fill in real values for local runs
npm run dev                      # http://localhost:8787
npm run typecheck
npm test                         # needs Bun; end-to-end with a fake Garmin API, no account needed

The test walks the whole path a client takes: discovery → dynamic client registration → consent page → password → token exchange → MCP calls in both protocol eras.

Layout: src/index.ts wiring · src/auth.ts sign-in and consent · src/mcp.ts protocol · src/tools.ts tools · src/garmin.ts API client · src/dates.ts date ranges.

Garmin's response shapes are only partly documented. If a field comes back empty for your device, open an issue with the tool name and (redacted) response.

Credits

Built on ideas and endpoint knowledge from garmin/connect-personal-api-python (Garmin's official client), Mason-Levyy/garmin-personal-mcp and Janhsen/ha-garmin-personal.

Disclaimer

This is an independent project, not affiliated with or endorsed by Garmin Ltd. Garmin and Garmin Connect are trademarks of Garmin Ltd. or its subsidiaries. Use it only with your own account, in line with Garmin's Personal API terms. Not medical advice.

License

MIT