Multi-User Support

When multiple users are configured, the app automatically identifies who stepped on the scale based on the measured weight. The setup wizard walks you through adding users and setting weight ranges — no manual YAML editing needed.

How It Works

1. Someone steps on the scale
2. The app reads the weight and identifies the user by their weight range
3. Body composition is calculated using that user's profile (height, age, gender, athlete mode)
4. Data is exported to that user's configured exporters
5. last_known_weight is updated in config.yaml for better future matching

Each user defines a weight_range so the app knows who's who:

users:
  - name: Alice
    weight_range: { min: 50, max: 70 }
    last_known_weight: null
  - name: Bob
    weight_range: { min: 75, max: 100 }
    last_known_weight: 85.5

Weight Matching

The app uses a 4-tier priority system to identify users:

Priority	Condition	Behavior
1	Single user	Always matches (warns if weight is outside range)
2	Exact range match	One user's range contains the weight
3	Overlapping ranges	Multiple matches — tiebreak by last_known_weight proximity, then config order
4	No range match	Closest last_known_weight

If no match is found, the unknown_user strategy decides what happens:

Strategy	Behavior
nearest (default)	Picks the closest range midpoint (with a warning)
log	Logs a warning and skips
ignore	Silently skips

Drift Detection

After matching, the app checks if the weight falls in the outer 10% of the user's range. If it does, a warning is logged — so you can adjust the range before mismatches start happening.

For example, if Alice's range is 50–70 kg and she weighs 68.5 kg, the app warns that she's near the upper boundary.

Automatic Weight Tracking

After each measurement, the matched user's last_known_weight is automatically updated in config.yaml. This improves matching accuracy over time, especially when ranges overlap. Updates are debounced (5s) and skipped for changes under 0.5 kg.

Per-User Exporters

By default, all users share global_exporters. If a user needs different export targets (e.g., separate Garmin accounts), define exporters on that user — it completely replaces global_exporters for them:

users:
  - name: Alice
    # ...
    exporters:
      - type: garmin
        email: 'alice@example.com'
        password: '${ALICE_GARMIN_PASSWORD}'

  - name: Bob
    # ...
    exporters:
      - type: garmin
        email: 'bob@example.com'
        password: '${BOB_GARMIN_PASSWORD}'

global_exporters:
  - type: influxdb
    # ... shared by users without their own exporters list

Exporter behavior in multi-user mode

Exporter	What changes
MQTT	Publishes to {topic}/{slug}, per-user HA device + LWT
InfluxDB	Adds user={slug} tag to line protocol
Webhook	Adds user_name + user_slug fields to JSON
Ntfy	Prepends [{name}] to notification
Garmin	One account per user via per-user exporter config

Live Config Reload

On Linux/macOS, you can reload config.yaml without restarting by sending SIGHUP:

kill -HUP $(pgrep -f "ble-scale-sync")

The config is re-validated before applying. If validation fails, the previous config is kept.