pycync_lan (cync_lan)

Important

DNS redirection REQUIRED

Async HTTP/MQTT LAN controller for Cync/C by GE devices. Local only control of most Cync devices via MQTT JSON payloads following the Home Assistant MQTT JSON schema. This project masquerades as the cloud server, allowing you to control your devices locally.

This is a work in progress, and may not work for all devices. See known devices for more information. Battery powered devices are currently not supported due to them being BTLE only.

Forked from cync-lan and cync2mqtt - All credit to iburistu and juanboro

Prerequisites

• Python 3.8+ (Walrus [:=] operator used)
• A minimum of 1, non battery powered, Wi-Fi (Direct Connect) Cync / C by GE device to act as the TCP <-> BT bridge (always on)
• Cync account with devices added
• MQTT broker (I recommend EMQX)
• Export devices from the Cync cloud to a YAML file; first export requires account email, password and an OTP emailed to you
• DNS override/redirection for cm.gelighting.com or cm-ge.xlink.cn to a local host that will run cync-lan
• Non Docker: Create self-signed SSL certs using CN=*.xlink.cn for the server. You can use the create_certs.sh script
• Optional: Firewall rules to allow cync devices to talk to cync-lan (VLANs?)

Note

You still need to use your Cync account to add new devices as you acquire them.

Installation

Important

You must create a virtualenv and download the cync-lan.py script in order to export your Cync devices from the Cync cloud API. Even if you only plan on using a docker set-up. This requires your email, password and the code that will be emailed to you during export.

You will want to save the virtualenv setup for future use. If you add new devices to your Cync account, you need to export the config. Please see Install docs for more information.

Updating Docker Container

Updating using a new image

• cd to cync-lan docker directory where docker-compose.yaml is located
• run: docker compose pull && docker compose up -d --force-recreate

'Upgrade in-place'

If you want to update the container in-place, you can:

• cd to cync-lan docker directory where docker-compose.yaml is located
• wget 'https://raw.githubusercontent.com/baudneo/cync-lan/refs/heads/python/src/cync-lan.py'
• edit docker-compose.yaml and uncomment the bind mount line in volumes for ./cync-lan.py

  • volumes:
      # Create a ./config dir and place the exported config file in this directory
      - ./config:/root/cync-lan/config
      # Want to run custom code or upgrade in place? Bind-mount the custom/upgraded cync-lan.py into the container!
      #- ./cync-lan.py:/root/cync-lan/cync-lan.py  <---- uncomment this line
    
• docker compose up -d --force-recreate to finalize the upgrade in place.

Re-routing / Overriding DNS

Warning

After freshly redirecting DNS: Devices that are currently talking to the Cync cloud will need to be power cycled before they make a DNS request and connect to the local cync-lan server.

There are detailed instructions for OPNSense and Pi-hole. See DNS docs for more information.

Tips

See Tips for more information on how to get the most out of this project.

Config file

See the example config file

Export config from Cync cloud API

There is an export sub command that will query the Cync cloud API and export all homes and each homes devices to a YAML file.

CLI arguments

You can always supply --help to the cync-lan.py script to get a breakdown. Please see the sub-command docs for more information.

Env Vars

Note

The CYNC_MQTT_URL variable is deprecated and will be removed in a future release. For now, it will be parsed into CYNC_MQTT_HOST, CYNC_MQTT_PORT, CYNC_MQTT_USER, and CYNC_MQTT_PASS.

Variable	Description	Default
CYNC_MQTT_HOST	Host of MQTT broker	homeassistant.local
CYNC_MQTT_PORT	Port of MQTT broker	1883
CYNC_MQTT_USER	Username for MQTT broker
CYNC_MQTT_PASS	Password for MQTT broker
CYNC_MQTT_CONN_DELAY	Delay between MQTT re-connections (seconds)	10
CYNC_DEBUG	Enable debug logging	0
CYNC_RAW_DEBUG	Enable raw binary message debug logging	0
CYNC_CERT	Path to cert file	certs/server.pem
CYNC_KEY	Path to key file	certs/server.key
CYNC_PORT	Port to listen on (shouldn't need to change)	23779
CYNC_HOST	Interface to listen on	0.0.0.0
CYNC_TOPIC	MQTT topic	cync_lan
CYNC_HASS_TOPIC	Home Assistant topic	homeassistant
CYNC_HASS_STATUS_TOPIC	HASS status topic for birth / will	status
CYNC_HASS_BIRTH_MSG	HASS birth message	online
CYNC_HASS_WILL_MSG	HASS will message	offline
CYNC_CMD_BROADCASTS	Number of WiFi devices to send state commands to	2
CYNC_MAX_TCP_CONN	Maximum Wifi devices allowed to connect at a time	8
CYNC_TCP_WHITELIST	Comma separated string of allowed IPs	Allow ALL IPs

Controlling devices

Devices are controlled by JSON MQTT messages. This was designed to be used with Home Assistant, but you can use any MQTT client to send messages to the MQTT broker.

Please see Home Assistant MQTT documentation for more information on JSON payloads. This repo will try to stay up to date with the latest Home Assistant MQTT JSON schema.

Home Assistant

This script uses the MQTT discovery mechanism in Home Assistant to automatically add devices. You can control the Home Assistant MQTT topic via the environment variable CYNC_HASS_TOPIC (default: homeassistant).

Debugging / socat

If your devices are not responding to commands, it's likely that the TCP communication on the device is different. You can either open an issue and I can walk you through getting good debug logs, or you can use socat to inspect (MITM) the traffic of the device communicating with the cloud server in real-time yourself by running:

# make sure to create the self-signed certs first
# Older firmware devices
socat -d -d -lf /dev/stdout -x -v 2> dump.txt ssl-l:23779,reuseaddr,fork,cert=certs/server.pem,verify=0 openssl:34.73.130.191:23779,verify=0
# Newer firmware devices (Notice the last IP change)
sudo socat -d -d -lf /dev/stdout -x -v 2> dump.txt ssl-l:23779,reuseaddr,fork,cert=certs/server.pem,verify=0 openssl:35.196.85.236:23779,verify=0

In dump.txt you will see the back-and-forth communication between the device and the cloud server. > is device to server, < is server to device.

Firewall

Once the devices are local, they must be able to initiate a connection to the cync-lan server. If you block them from the internet, don't forget to allow them to connect to the cync-lan server.

OPNsense Example

Please see the example in the troubleshooting docs.

Power cycle devices after DNS re-route

Devices make a DNS query on first startup (or after a network loss, like AP reboot) - you need to power cycle all devices that are currently connected to the Cync cloud servers before they request a new DNS record and will connect to the local cync-lan server.

Troubleshooting

If you are having issues, please see the Troubleshooting docs for more information.

Buy devices to be supported

If you really want a device added, purchase it from this Amazon wish list, and it will be sent to me. I will add support ASAP.