Hi everyone,
I’m sharing Cross-Platform Device Sync, an independent Home Assistant community custom integration for one repetitive problem:
When the same Home Assistant devices should appear in Google Home, HomeKit, and Matter ecosystems through Matterbridge, you should not have to select and maintain the same entities separately for every platform.
Choose the devices once from a Home Assistant-side source, select the target platforms, and the integration continuously keeps those exposure lists aligned. Each target can still have its own additions and exclusions.
What this is — and what it is not
This is not a Home Assistant backup, failover, clustering, migration, or instance-to-instance synchronization tool.
It does not copy a Home Assistant installation, automations, history, settings, entity states, or device data to another HA server. It also does not copy live state between Google Home, Apple Home, and Matter controllers.
It manages one specific thing:
Which Home Assistant entities should be exposed to each selected smart-home platform.
For example, you can choose a dashboard view as the source. When an entity is added to that view, the integration can add it to the Home Assistant-side Google Home, HomeKit, or Matterbridge exposure configuration you selected. When the entity leaves the source, it can remove only that platform exposure. The HA entity itself is not copied, deleted, or controlled.
How it works
Choose a source of truth from:
- one or more Home Assistant dashboard views;
- a manually selected entity list; or
- the current Home Assistant-side Google Home, HomeKit, or Matterbridge exposure list.
Then independently select Google Home, HomeKit, and/or Matterbridge as targets. Each target has its own Always include and Exclude lists, so the platforms do not need to expose identical devices.
The integration performs one complete check when Home Assistant or the integration starts. Dashboard and HomeKit sources use change events where available; sources without a suitable event use a 15-second fallback check. Rapid changes are combined, and unchanged results are treated as a no-op.
Safety and predictable changes
- Preview additions and removals with
platform_sync.preview. - Back up target configuration before writes.
- Read back exact results and attempt reverse-order rollback after a failure.
- Never turn devices on or off or control locks, alarms, climate devices, cameras, or media playback.
- Never delete Home Assistant entities or native platform pairings.
- Create no extra sensor, button, or settings entity.
- Use no project-provided cloud service or telemetry endpoint.
For each selected target, the generic final list is:
(source - exclusions) ∪ always-included entities
Because synchronization is exact, an existing exposure outside the final list can be removed from that selected target even if it predates this integration. Unselected targets are untouched. Please create a full HA backup and review a preview before the first synchronization or a major source change.
Version 0.6.2 also adds guarded Matterbridge recovery: it waits for a verified backup, restarts matterbridge-hass first, and attempts at most one full Matterbridge process restart only when exact runtime readback still fails. Missing credentials, unreachable APIs, disabled plugins, changed allowlists, competing filters, and other ambiguous conditions remain fail closed.
Install with HACS
This project is installed as a HACS custom repository:
- Open HACS → Integrations → three-dot menu → Custom repositories.
- Enter
jameslu34/ha-platform-syncand select Integration. - Download Cross-Platform Device Sync, create a Home Assistant backup, and restart HA.
- Open Settings → Devices & services → Integrations → Add integration and search for Cross-Platform Device Sync.
Open the custom repository in HACS
The platform integrations you select must already be configured. Google Home targets require Home Assistant Google Assistant with expose_by_default: false, a dedicated entity_config include file, and google_assistant.request_sync. HomeKit requires existing HA HomeKit Bridge or Accessory entries. Matterbridge requires a connected matterbridge-hass plugin.
The current release was live-validated with Home Assistant Core 2026.8.3, Matterbridge 3.10.7, and matterbridge-hass 1.5.0. These are tested versions, not declared minimum versions.
Documentation and feedback
Feedback and real-world testing reports are welcome, especially from people using different source and target combinations. Please sanitize diagnostics and never post credentials, private host names, or unredacted configuration.
A successful Home Assistant-side readback does not prove that a native Google Home, Apple Home, or Matter controller app has already refreshed; those apps still need to be checked separately.
Cross-Platform Device Sync is an independent, community-maintained custom integration. It is not part of Home Assistant Core and is not reviewed, maintained, or supported by the Home Assistant project. It is not affiliated with or endorsed by Home Assistant, Nabu Casa, Google, Apple, or Matterbridge.
Version 0.6.1 and later use the PolyForm Noncommercial License 1.0.0. This is a noncommercial source-available project, not an OSI-approved open-source project.
Cross-Platform Device Sync v0.7.1 is now available!