eufy-garmin-sync 1.3.0

Sync Eufy smart scale body composition data to Garmin Connect

eufy-garmin-sync

Syncs body composition data from a Eufy smart scale to Garmin Connect. Weight, body fat %, muscle mass, bone mass, hydration, BMR, visceral fat, and metabolic age all come through.

macOS only. Requires Python 3.9+ and a terminal. Setup is guided - you just answer a few prompts.

The problem

Eufy scales sync to Apple Health, Fitbit, and Google Fit - but not Garmin. If you use Garmin for training, your body comp data is stuck in a separate app. This fixes that.

Why not just use python-garminconnect?

Every Python library that talked to Garmin broke in March 2026. Garmin put Cloudflare in front of their SSO, which blocks any login that doesn't come from a real browser. garth is deprecated, python-garminconnect can't authenticate anymore, and there's no official API.

This project gets around it with Playwright. On first run, a real Chromium window opens and you log in normally. OAuth2 tokens get saved locally and refresh on their own for about a year. After that first login, no browser needed - body comp data goes up as FIT files through Garmin's upload endpoint.

Install

You need Python 3.9+, a Eufy scale with cloud sync, and a Garmin Connect account.

First, install pipx if you don't have it:

brew install pipx

Or if you don't use Homebrew: pip3 install pipx

Then install and run:

pipx install eufy-garmin-sync
eufy-sync

Setup is guided on first run - enter your credentials, log into Garmin in the browser that opens, and your data syncs automatically.

Note: If you've cloned this repo, run pipx commands from outside the repo directory to avoid path conflicts (e.g., cd /tmp && pipx install eufy-garmin-sync).

Usage

eufy-sync                      # sync new measurements
eufy-sync --status           # check last sync + token health
eufy-sync --dry-run          # preview without uploading
eufy-sync --reauth           # re-login to Garmin if tokens expire
eufy-sync --update-password  # change stored passwords
eufy-sync --backfill-days 30 # sync last 30 days
eufy-sync --verbose          # show detailed sync logs
eufy-sync --install-agent   # set up automatic sync
eufy-sync --uninstall-agent # remove automatic sync
eufy-sync --uninstall       # remove all data and clean up

Automatic sync (macOS)

On first run, you'll be asked if you want to sync automatically every 4 hours. If you say yes, a macOS Launch Agent is installed that runs in the background - weigh yourself, open your laptop later, and it syncs on its own.

Logs go to /tmp/eufy-garmin-sync.log. You get a macOS notification if something fails.

To disable: eufy-sync --uninstall-agent

How it works

Eufy Cloud API --> eufy_client.py --> transform.py --> garmin_client.py --> Garmin Connect
(fetch history)    (auth + pull)     (filter, dedup)   (FIT file + upload)
                                          |
                                      state.db
                                   (sync watermark)

1. Authenticate to Eufy cloud API, pull measurement history
2. Check local SQLite DB for what's already been synced
3. Check Garmin for existing entries on the same date (handles multi-machine dedup)
4. Generate a FIT binary file for each new measurement
5. Upload to Garmin Connect, record in DB

Security

Your credentials and tokens are stored in ~/.garmin-sync/ with 600 permissions (only your user can read). They are only sent to Eufy and Garmin's own servers over HTTPS. They are never logged, uploaded, or transmitted anywhere else. The only other outbound call is a weekly version check to pypi.org (no credentials sent). You can verify this yourself - the codebase is small and the outbound calls are in eufy_client.py, garmin_auth.py, and the update checker in cli.py.

If your machine is compromised, these tokens could be used to access your Garmin account - but that's true of any saved login.

Known quirks

Weight precision: The Eufy cloud API returns weight at ~0.05 kg resolution, which can differ slightly from what the Eufy app displays (the app may read from Bluetooth/local storage with higher precision). In testing, most days match within 0.1 lbs, but occasional readings can be off by up to ~0.5 lbs. If Garmin displays in lbs, the kg-to-lbs conversion adds a bit more rounding on top.

Tests

pytest tests/ -v

Disclaimer

Uses unofficial APIs for both Eufy and Garmin. Could break if either company changes things. Use at your own risk.