Description

Since upgrading Home Assistant to 2026.10.1 (which ships python-kasa==0.11.0.1), a Tapo H200 hub that has no child devices paired fails on almost every update with KeyError: 'child_component_list' in SmartDevice._create_delete_children(). All of its entities (siren, LED, alarm sound select) become unavailable. Reloading the config entry only helps for a few minutes.

A second H200 hub on the same network, with 8 child devices (T110 / T315) and firmware 1.7.5, is not affected.

Environment

• python-kasa: 0.11.0.1, via Home Assistant 2026.10.1 (tplink integration). The same code is still on master.
• Device: Tapo H200, hardware 1.0, firmware 1.7.7 Build 20260917 rel.79232, region EU, SMART.TAPOHUB
• Child devices paired to this hub: none (it is only used as a siren)
• Previous working setup: Home Assistant 2026.9.4. Failures started a few hours after the upgrade and then repeated on every poll (about every 8 s) for more than 24 h.

Traceback

ERROR (MainThread) [homeassistant.components.tplink.coordinator] Unexpected error fetching <hub ip> data
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/helpers/update_coordinator.py", line 456, in _async_refresh
    self.data = await self._async_update_data()
  File "/usr/src/homeassistant/homeassistant/components/tplink/coordinator.py", line 78, in _async_update_data
    await self.device.update(update_children=self._update_children)
  File "/usr/local/lib/python3.14/site-packages/kasa/smart/smartdevice.py", line 279, in update
    children_changed = await self._update_children_info()
  File "/usr/local/lib/python3.14/site-packages/kasa/smartcam/smartcamdevice.py", line 116, in _update_children_info
    changed = await self._create_delete_children(
        child_info, self._last_update["getChildDeviceComponentList"]
    )
  File "/usr/local/lib/python3.14/site-packages/kasa/smart/smartdevice.py", line 114, in _create_delete_children
    for child in child_device_components_resp["child_component_list"]
KeyError: 'child_component_list'

Observations

• The failure is intermittent at the device level. A diagnostics dump taken at another moment shows well-formed empty responses:

  "getChildDeviceList": {"start_index": 0, "sum": 0, "child_device_list": []},
  "getChildDeviceComponentList": {"start_index": 0, "sum": 0, "child_component_list": []}

  So on an empty hub, this firmware sometimes returns a getChildDeviceComponentList result that has no child_component_list key, while getChildDeviceList is still a non-empty dict. I could not capture the malformed payload itself: the debug log does not include the raw response.

• In SmartCamDevice._update_children_info(), the getChildDeviceList response goes through _try_get_response(..., {}), but getChildDeviceComponentList is indexed directly. _create_delete_children() then assumes the key is always there.

Suggested fix

Treat a missing component list as empty, the same way a missing child list is handled:

smart_children_components = {
    child["device_id"]: child
    for child in child_device_components_resp.get("child_component_list", [])
}

I applied this one-line change locally in kasa/smart/smartdevice.py. The hub has been stable since, with no more errors and entities available. It might also be worth using _try_get_response(self._last_update, "getChildDeviceComponentList", {}) in smartcamdevice.py.