Left behind notifications

[nprez83]

First of thank you very much for the hard work that's taken to get this integration to where it is.

One of the main things missing in Google's FMD imo is left behind notifications. I was wondering if there's anyway to overcome that using this integration. I've currently enabled this using distance calculated via GPS coordinates, but that's slow and prone to inaccuracies, especially when moving fast (eg driving).

Is there any way to use this API/integration to detect when the tracker is connected to my phone? This way we could enable notifications based on Bluetooth rather than GPS.

[jleinenbach]

Basically a good idea, but relying on is_own_report via the Cloud API is unsuitable for real-time separation alerts due to the polling latency (defaulting to 5 minutes) and the fact that the status only updates when a new device locates and reports the tracker. If the tracker is left in a low-traffic area, no new report will be generated, causing the status to incorrectly remain "connected" for an indefinite period. Consequently, this metric acts merely as a retrospective indicator of the last reporter rather than a reliable trigger for instant "left behind" notifications.

Simply reducing the polling interval is ineffective, as the Google API enforces internal rate limits and data refresh latencies that far exceed the timeframe necessary for immediate alerts. Reliable separation detection requires an event-driven trigger implemented locally on the smartphone to instantly report a lost connection, rather than relying on delayed cloud status updates.

Cloud API (is_own_report): This flag reflects the source of the last received location report, not the live connection state. It only updates when a different device in the Find My network reports the tracker. In areas with few Android devices, this can take minutes to hours — or never update at all if no other participant is nearby.

Companion App (local BLE): The Android Companion App reports connected BLE devices via its bluetooth_connection sensor. However, FMDN tracker connections are managed by Google Play Services in a sandboxed process. Android's getConnectedDevices(GATT) only returns connections owned by the calling app — the tracker's GATT connection, held by Google Play Services, is invisible to third-party apps. The tracker appears as "bonded" (paired via Fast Pair) but not as "connected."

Both approaches fail for the same fundamental reason: Google does not expose the tracker's real-time BLE connection state to third-party applications or APIs.

[nprez83]

I was afraid this was the case 😔. Thanks for the explanation though.