I believe you need to listen to the state_changed event and look at the entity and the context.
I just tried to turn on one of our lights with GH and this is the state changed event for that event:
{
"event_type": "state_changed",
"data": {
"entity_id": "light.sonoff_1000cb7905",
"old_state": {
"entity_id": "light.sonoff_1000cb7905",
"state": "off",
"attributes": {
"effect_list": [
"Colorful",
"Colorful Gradient",
"Colorful Breath",
"DIY Gradient",
"DIY Pulse",
"DIY Breath",
"DIY Strobe",
"RGB Gradient",
"DIY Gradient",
"RGB Breath",
"RGB Strobe",
"Music"
],
"supported_color_modes": [
"hs"
],
"manufacturer": "SONOFF",
"model": "L1",
"sw_version": "PSF-BTA-GL v2.9.1",
"cloud": "online",
"rssi": -21,
"friendly_name": "Tavlan",
"supported_features": 21,
"templates": {
"icon": "mdi:image-frame"
}
},
"last_changed": "2022-06-14T20:46:02.741882+00:00",
"last_updated": "2022-06-14T20:46:02.741882+00:00",
"context": {
"id": "78273708839b51f2a596c459cc37a9cb",
"parent_id": "e9cf397b4add099013d6f48c0078b804",
"user_id": null
}
},
"new_state": {
"entity_id": "light.sonoff_1000cb7905",
"state": "on",
"attributes": {
"effect_list": [
"Colorful",
"Colorful Gradient",
"Colorful Breath",
"DIY Gradient",
"DIY Pulse",
"DIY Breath",
"DIY Strobe",
"RGB Gradient",
"DIY Gradient",
"RGB Breath",
"RGB Strobe",
"Music"
],
"supported_color_modes": [
"hs"
],
"color_mode": "hs",
"brightness": 255,
"hs_color": [
29.032,
100
],
"rgb_color": [
255,
123,
0
],
"xy_color": [
0.617,
0.37
],
"effect": "Colorful",
"manufacturer": "SONOFF",
"model": "L1",
"sw_version": "PSF-BTA-GL v2.9.1",
"cloud": "online",
"rssi": -21,
"friendly_name": "Tavlan",
"supported_features": 21,
"templates": {
"icon": "mdi:image-frame"
}
},
"last_changed": "2022-06-15T12:34:15.796455+00:00",
"last_updated": "2022-06-15T12:34:15.796455+00:00",
"context": {
"id": "b20320135304803cf6f3b6c10d1fbc03",
"parent_id": null,
"user_id": "9a2b0a52bd8342fcb96f6df6a128a04c"
}
}
},
"origin": "LOCAL",
"time_fired": "2022-06-15T12:34:15.796455+00:00",
"context": {
"id": "b20320135304803cf6f3b6c10d1fbc03",
"parent_id": null,
"user_id": "9a2b0a52bd8342fcb96f6df6a128a04c"
}
}