Hey y’all, sharing a project that may be useful to anyone running Cync / C by GE Lighting who wants it working without the cloud.
What it is: a native Home Assistant integration. Home Assistant runs a small TCP/TLS server, your Cync devices connect to it instead of Cync’s cloud (via a DNS override at your router), and from then on every command and state update stays on your LAN. Lights keep working with the internet down.
What’s different from the existing options. Local Cync control isn’t new, @baudneo’s cync-lan has been around a while, and this is a fork of it. What’s new here is that it’s a native integration rather than a bridge:
- no MQTT broker
- no Docker
- set up through the normal config flow, no YAML
- devices arrive as real HA entities, lights, switches, plugs, fans, scenes, buttons, selects, numbers, binary sensors
Requirements, please read before trying:
- DNS redirection is mandatory. You must point the
xlink.cn-family hostnames at your HA host from your router / Pi-hole / AdGuard / dnsmasq. Without it nothing connects. Devices already talking to the cloud need a power cycle afterwards. - At least one mains-powered Wi-Fi (“Direct Connect”) Cync device, to act as the TCP↔Bluetooth bridge for the rest of your mesh. Battery devices can’t do this.
- Your Cync account email and password, plus inbox access, Cync emails a one-time code during setup.
- Home Assistant 2024.11.0 or newer.
- A free port on the HA host (23779 by default).
You still need the official Cync app to add new devices to your account. This controls what’s already there.
What works well: on/off, brightness, colour temperature, RGB, fans, plugs, switches, scenes, and state updates pushed from the devices themselves.
What’s experimental: a good chunk of the more advanced command set, hub-side scenes and schedules, motion-sensor tuning, indicator-LED control, group commands, is reverse-engineered from the app, and some of those commands
have a header field predicted from a length formula rather than confirmed against a packet capture. Those are all behind an opt-in “experimental” toggle that’s off by default, and they’re documented as unconfirmed in the repo.
They work or they silently do nothing; they won’t damage anything. If you try them, I’d like to hear either result, that feedback is the main thing standing between “probably right” and “confirmed”, and I can only test against the hardware I own.
Two cautions inherited from upstream, both still worth respecting:
- Don’t firmware-upgrade Cync devices once you’re using this. It would be trivial for Savant to break this method of local control.
- Don’t contact GE / Savant support about problems while running this. Open an issue on the repo instead.
Install: HACS → custom repository. (Submitted for the HACS default list; pending review.) or use the button below:
Full setup, all the entity types, services, example automations and troubleshooting are in the integration’s own README. There’s also a Docker/MQTT add-on and a standalone protocol library in the same repo if the integration isn’t the shape you want.
Credit where it’s due: this builds directly on @baudneo’s cync-lan and the protocol work behind it.