Standing on other people's work
homebridge-wiz-lan by 9constellations and its contributors. This plugin exists because WiZ's broadcast discovery cannot work on a mesh that drops broadcast frames, which is a property of the network rather than a defect in that plugin. Its handling of the protocol is careful work: per-device offline tracking, coalesced probes, and write generations that stop a delayed reply rolling back a fresh write. Several behaviours documented here were learned by reading it.
Accessory UUIDs are generated the same way it generates them, deliberately, so that swapping one for the other keeps every bulb's HomeKit room, scenes and automations.
The WiZ protocol has no public specification. What is implemented here comes from the community's reverse engineering, chiefly pywizlight, and from asking real bulbs what they do.
OpenBridge provides the HAP bridge, the device model and the plugin host.
hap-nodejs implements the HomeKit Accessory Protocol underneath all of it.
Sponsorship
This is MIT licensed and free. If it is useful, sponsorship helps keep it maintained: device integrations need hardware to test against, and hardware costs money.