MQTT discovery configuration for HA deprecated in HA Core 2026.4

[Kaibob2]

The Problem

Seit HA 2025.10 erscheint folgender Eintrag im Protokoll:

Logger: homeassistant.components.mqtt.entity
Quelle: components/mqtt/entity.py:1455
Integration: MQTT ([Dokumentation](https://www.home-assistant.io/integrations/mqtt), [Probleme](https://github.com/home-assistant/core/issues?q=is%3Aissue+is%3Aopen+label%3A%22integration%3A+mqtt%22))
Erstmals aufgetreten: 09:56:58 (19 Vorkommnisse)
Zuletzt protokolliert: 09:56:59

- The configuration for entity sensor.watermeter_error uses the deprecated option `object_id` to set the default entity id. Replace the `"object_id": "watermeter_error"` option with `"default_entity_id": "sensor.watermeter_error"` in your published discovery configuration to fix this issue, or contact the maintainer of the integration that published this config to fix this. This will stop working in Home Assistant Core 2026.4
- The configuration for entity sensor.watermeter_rate_per_time_unit uses the deprecated option `object_id` to set the default entity id. Replace the `"object_id": "watermeter_rate_per_time_unit"` option with `"default_entity_id": "sensor.watermeter_rate_per_time_unit"` in your published discovery configuration to fix this issue, or contact the maintainer of the integration that published this config to fix this. This will stop working in Home Assistant Core 2026.4
- The configuration for entity sensor.watermeter_rate_per_digitization_round uses the deprecated option `object_id` to set the default entity id. Replace the `"object_id": "watermeter_rate_per_digitization_round"` option with `"default_entity_id": "sensor.watermeter_rate_per_digitization_round"` in your published discovery configuration to fix this issue, or contact the maintainer of the integration that published this config to fix this. This will stop working in Home Assistant Core 2026.4
-  The configuration for entity sensor.watermeter_timestamp uses the deprecated option `object_id` to set the default entity id. Replace the `"object_id": "watermeter_timestamp"` option with `"default_entity_id": "sensor.watermeter_timestamp"` in your published discovery configuration to fix this issue, or contact the maintainer of the integration that published this config to fix this. This will stop working in Home Assistant Core 2026.4
- The configuration for entity sensor.watermeter_json uses the deprecated option `object_id` to set the default entity id. Replace the `"object_id": "watermeter_json"` option with `"default_entity_id": "sensor.watermeter_json"` in your published discovery configuration to fix this issue, or contact the maintainer of the integration that published this config to fix this. This will stop working in Home Assistant Core 2026.4

Version

16.0.0 forked to support OV3660

Logfile

[0d00h00m00s] 2025-10-02T08:17:25	<INF>	[MAIN] =================================================
[0d00h00m00s] 2025-10-02T08:17:25	<INF>	[MAIN] ==================== Start ======================
[0d00h00m00s] 2025-10-02T08:17:25	<INF>	[MAIN] =================================================
[0d00h00m00s] 2025-10-02T08:17:25	<INF>	[SDCARD] Basic R/W check started...
[0d00h00m00s] 2025-10-02T08:17:25	<INF>	[SDCARD] Basic R/W check successful
[0d00h00m00s] 2025-10-02T08:17:25	<INF>	[MAIN] PSRAM size: 8388608 byte (8MB / 64MBit)
[0d00h00m00s] 2025-10-02T08:17:25	<INF>	[MAIN] Total heap: 4377019 byte
[0d00h00m03s] 2025-10-02T08:17:28	<INF>	[MAIN] Camera info: PID: 0x3660, VER: 0x00, MIDL: 0x00, MIDH: 0x00
[0d00h00m03s] 2025-10-02T08:17:28	<INF>	[SNTP] TimeServer: pool.ntp.org
[0d00h00m03s] 2025-10-02T08:17:28	<INF>	[SNTP] TimeZone not set, using default: CET-1CEST,M3.5.0,M10.5.0/3
[0d00h00m03s] 2025-10-02T08:17:28	<INF>	[SNTP] Configuring NTP Client...
[0d00h00m03s] 2025-10-02T10:17:28	<INF>	[SNTP] Time zone set to CET-1CEST,M3.5.0,M10.5.0/3
[0d00h00m03s] 2025-10-02T10:17:28	<INF>	[SNTP] time zone: +0200 Delta to UTC: 7200 seconds
[0d00h00m03s] 2025-10-02T10:17:28	<INF>	[SNTP] Time is already set: 2025-10-02 10:17:28
[0d00h00m03s] 2025-10-02T10:17:28	<INF>	[MAIN] CPU frequency: 160 MHz
[0d00h00m03s] 2025-10-02T10:17:28	<INF>	[SDCARD] Folder/file presence check started...
[0d00h00m03s] 2025-10-02T10:17:28	<INF>	[SDCARD] Folder/file presence check successful
[0d00h00m03s] 2025-10-02T10:17:28	<INF>	[MAIN] Tag: 'ov3660', Release: ov3660 (Commit: bdc4bef), Date/Time: 2025-09-29 08:47, Web UI: Release: ov3660 (Commit: bdc4bef)
[0d00h00m03s] 2025-10-02T10:17:28	<INF>	[MAIN] Reset reason: Via esp_restart
[0d00h00m03s] 2025-10-02T10:17:28	<INF>	[WLANINI] SSID: xxxxxxx
[0d00h00m03s] 2025-10-02T10:17:28	<INF>	[WLANINI] Password: XXXXXXXX
[0d00h00m03s] 2025-10-02T10:17:28	<INF>	[WLANINI] Hostname: wasserzaehler
[0d00h00m03s] 2025-10-02T10:17:28	<INF>	[WLANINI] RSSIThreshold: -75
[0d00h00m03s] 2025-10-02T10:17:28	<INF>	[MAIN] WLAN config loaded, init WIFI...
[0d00h00m03s] 2025-10-02T10:17:28	<INF>	[WIFI] Automatic interface config --> Use DHCP service
[0d00h00m03s] 2025-10-02T10:17:28	<INF>	[WIFI] Set hostname to: wasserzaehler
[0d00h00m03s] 2025-10-02T10:17:28	<INF>	[WIFI] Init successful
[0d00h00m06s] 2025-10-02T10:17:31	<INF>	[WIFI] Connected to: FriBo, RSSI: -53
[0d00h00m07s] 2025-10-02T10:17:32	<INF>	[WIFI] Assigned IP: 192.168.0.162
[0d00h00m10s] 2025-10-02T10:17:35	<INF>	[SNTP] Time is synced with NTP Server pool.ntp.org: 2025-10-02 10:17:35
[0d00h00m11s] 2025-10-02T10:17:36	<INF>	[MAIN] Device info: CPU cores: 2, Chip revision: 301
[0d00h00m11s] 2025-10-02T10:17:36	<INF>	[MAIN] SD card info: Name: MSD, Capacity: 30024MB, Free: 29995MB
[0d00h00m13s] 2025-10-02T10:17:38	<INF>	[MAIN] Initialization completed successfully
[0d00h00m16s] 2025-10-02T10:17:41	<INF>	[TFLITE] Trying to load the model. If it crashes here, it ist most likely due to a corrupted model!
[0d00h00m16s] 2025-10-02T10:17:41	<INF>	[TFLITE] Trying to load the model. If it crashes here, it ist most likely due to a corrupted model!
[0d00h00m16s] 2025-10-02T10:17:41	<INF>	[LOGFILE] Set log level to WARNING

Expected Behavior

No response

Screenshots

No response

Additional Context

No response

[z-master42]

Changing object_id to default_entity_id in this line will only work for HA >= 2025.10.
For a transitional period, both variants must therefore work.

AI-on-the-edge-device/code/components/jomjol_mqtt/server_mqtt.cpp

Line 104 in f3e3ce5

"\"object_id\": \"" + maintopic + "_" + configTopic + "\"," + // This used to generate the Entity ID

As it stands, it will work until HA 2026.4.

@Kaibob2 could you perhaps clarify the title a little, to make it clear that this is about Home Assistant MQTT Discovery and not a general MQTT problem?

[Kaibob2]

I see, thanks for clarification.

[Seger85]

@z-master42 @Kaibob2

Hello everyone,

I apologise for writing this here, I know it's a HA change, but maybe someone can help me.
I have created several mqqt sensors via Configuration.yaml where the change needs to take place. I can also do this in conf.yaml, but then I lose my historical data. The error is then gone, but so is my data. Is there already a solution for this?

Thank you,
seger

`mqtt:
sensor:

name: Stromzähler Gesamtverbrauch
unique_id: Stromzähler Gesamtverbrauch
object_id: electricity.total_energy_consumption_kwh
state_topic: wmbusmeters/62936823
value_template: "{{ value_json.total_energy_consumption_kwh | round(1) }}"
state_class: total_increasing
device_class: energy
unit_of_measurement: kWh`

[z-master42]

@Seger85 I don't see any connection to AI on the edge.

This is an MQTT sensor configuration. Why is object_id even in there? I've created various MQTT sensors in YAML myself and I've never come across object_id. Can't you just delete that line? It's not supposed to be there at all.

See https://www.home-assistant.io/integrations/sensor.mqtt/

[Anto79-ops]

Changing object_id to default_entity_id in this line will only work for HA >= 2025.10. For a transitional period, both variants must therefore work.

AI-on-the-edge-device/code/components/jomjol_mqtt/server_mqtt.cpp

Line 104 in f3e3ce5

""object_id": "" + maintopic + "_" + configTopic + ""," + // This used to generate the Entity ID
As it stands, it will work until HA 2026.4.

@Kaibob2 could you perhaps clarify the title a little, to make it clear that this is about Home Assistant MQTT Discovery and not a general MQTT problem?

Hi, is this something that can be changed manually on the device itself (before a fix/update is issued)? thanks

[z-master42]

Nope. This is part of the firmware and must therefore be compiled.

[caco3]

Thanks for pointing it out. Before I update it in our firmware:
@z-master42, you write

Changing object_id to default_entity_id in this line will only work for HA >= 2025.10.

Do I understand it right? If I change it now, it will no longer work with HA < 2025.10?
If yo, we only should change it in a year... 😒

[Matze89x]

As @z-master42 said:

#3932 (comment)

Both variants must be output: object_id and default_entity_id.
After the year, you can remove one variant if necessary, or it will be ignored by the system.

Thank you very much.

[z-master42]

That's the way to do it.

Here's an example of how it's implemented in Zigbee2MQTT:
Koenkk/zigbee2mqtt#28560

https://github.com/Koenkk/zigbee2mqtt/blob/129a80d1bb1fc8a26017650b1fb9260d093b2763/lib/extension/homeassistant.ts#L1505-L1521

[Elle4u]

Will there be a new firmware in the next months? Or how can I get rid of the "error"?
I cannot see a code change so far.?

[z-master42]

Just ignore it.