MQTT and Shellies_Discovery_Gen2 not running?

othyssen · January 2, 2026, 6:29pm

I’m struggling with the discovery of my Shellies, ok I only have H&T and Smoke, yet.

I feel that I have done everything correctly (Mosquitto broker, MQTT, Python, and the YAMLs, but the devices won’t appear.
As they are battery driven (even USB connected) I woke them up and run Shellies Announce Gen2 manually, but still no device. I only see the MQTT integration itself

configuration.yaml
python_scrippt: added

Python script shellies_discovery_gen2.py is under config/python_scripts

automation.yaml
I even added my known three devices under device ids

device_ids: # enter the list of device IDs (MQTT prefixes) here
  - shellyhtg3-e4b3232f910c
  - shellyhtg3-e4b323309d20
  - shellyplussmoke-2cbcbbf7568c

I see the Shellies in Mosquitto

With MQTT Explorer I see the correct values of the devices, connecting every 5 minutes (H&T) and delivering them

In the Automation I see both
Shellies Announce Gen2
Shellies Discovery Gen2

but I only have traces for Announce, but none for Discovery.
It seems it won’t be triggered ?
The docs saying it cannot be run manually as it need the variables passed.

litte bit clueless …

Bieniu · January 2, 2026, 9:58pm

Devices should respond to the shellies_discovery topic, but that one is not visible in your screenshot.

How to debug

othyssen · January 4, 2026, 4:22pm

I can see shellies_discovery in the RPC part

The Python debug is not giving errors …

2026-01-04 11:06:44.392 INFO (MainThread) [homeassistant.components.automation.shellies_announce_gen2] Shellies Announce Gen2: Running automation actions
2026-01-04 11:06:44.392 INFO (MainThread) [homeassistant.components.automation.shellies_announce_gen2] Shellies Announce Gen2: Repeating sequence: Iteration 1 of 3 with item: 'shellyhtg3-e4b3232f910c'
2026-01-04 11:06:44.398 INFO (MainThread) [homeassistant.components.automation.shellies_announce_gen2] Shellies Announce Gen2: Repeat at step 1: Running automation actions
2026-01-04 11:06:44.398 INFO (MainThread) [homeassistant.components.automation.shellies_announce_gen2] Shellies Announce Gen2: Repeat at step 1: Executing step call service
2026-01-04 11:06:44.399 INFO (MainThread) [homeassistant.components.automation.shellies_announce_gen2] Initialized trigger Shellies Announce Gen2
2026-01-04 11:06:44.399 INFO (MainThread) [homeassistant.components.automation.shellies_discovery_gen2] Initialized trigger Shellies Discovery Gen2
2026-01-04 11:06:44.407 INFO (MainThread) [homeassistant.components.automation.shellies_announce_gen2] Shellies Announce Gen2: Repeat at step 1: Executing step call service
2026-01-04 11:06:44.447 INFO (MainThread) [homeassistant.components.automation.shellies_announce_gen2] Shellies Announce Gen2: Repeating sequence: Iteration 2 of 3 with item: 'shellyhtg3-e4b323309d20'
2026-01-04 11:06:44.447 INFO (MainThread) [homeassistant.components.automation.shellies_announce_gen2] Shellies Announce Gen2: Repeat at step 1: Running automation actions
2026-01-04 11:06:44.448 INFO (MainThread) [homeassistant.components.automation.shellies_announce_gen2] Shellies Announce Gen2: Repeat at step 1: Executing step call service
2026-01-04 11:06:44.461 INFO (MainThread) [homeassistant.components.automation.shellies_announce_gen2] Shellies Announce Gen2: Repeat at step 1: Executing step call service

Bieniu · January 4, 2026, 7:43pm

No, you can see the messages that Shellies Discovery sends to the device, you can’t see the response. Probably your MQTT config is wrong.

othyssen · January 6, 2026, 9:13am

I feel there is not much I can configure, checked various “tutorials”

When I test the wildcard “#” listener in “Listen to a topic”
the Shellies are contributing towards MQTT

How should MQTT behave from here, where do I need to check that everything is ok with my MQTT settings?

Bieniu · January 6, 2026, 9:38am

Shelly device must send the response to the shellies_discovery topic.
Remember that battery-powered devices (even if powered by USB) must be awake when the announce automation is triggered.

othyssen · January 6, 2026, 10:00am

I’m aware of it and already tried. Doing it again tonight.

Nikklaus · January 7, 2026, 10:42pm

hello world script is working…

If I try to run the py script, the action task response:

The action python_script.shellies_discovery_gen2 could not be executed. Error executing script (KeyError): ‘id’

Bieniu · January 7, 2026, 11:28pm

You cannot run this script manually, it needs data from the device response.

Show me your Shellie’s discovery automations and a screenshot from the MQTT configuration from device’s web UI.

Nikklaus · January 8, 2026, 9:02am

Thank you for your quick response.

Ahh, okay. The script is working, I got all the shellies in my MQTT integration.

othyssen · January 8, 2026, 5:42pm

success

I was inpatient with such 3 seconds press on the H&T to get it really awaken. I was under the impression that a fresh power on does the same

Thanks for accompany me @Bieniu