Home Assistant 2025.12 Legacy sensor template deprecation

[pansament]

After update to 2025.12 I have a bunch of repairs. I realy don`t understant how to modify "sensors.yaml" to make the repairs.
Can you please update or create a new example of sensors.yaml with new Template definitions? I tried for a few hours to update the sensors but I run in a bunch of errors.

I`ll add a screenshot.

Thanks.

[Anashost]

Sure. Home assistant introduced a breaking change where they change how sensor templates are created. The current methode will continue to work until 2026.6. But I will try to fix those next week and update the repository once i tested the new logic and make sure everything works well. I will let you know once it's done.

[pansament]

Thank you very much!

[Anashost]

Repo updated, lemme know how it goes.

[pansament]

Repo updated, lemme know how it goes.

Thank You Verry Much!!!

The flow to get rid of the repairs is simple.

1. Create a file templates.yaml containing code from this repo
2. Modify sensors.yaml to example from this repo
3. Edit configuration.yaml to include this files:
   sensor: !include sensors.yaml
   template: !include templates.yaml
4. Restart Home Assistant.

Works like a charm! Thank you!
I was waiting for this fix because programing is not my skill and I hate notifications!
I think this issue need to be open some time to be seen by others... But is closed.

Again...

THANK YOU!
From Romania.
Ionut Bucur.

[Anashost]

No worries. I’ve also updated the repo just now to include a nice card to show the weather data. Check it out.

[pansament]

I will later today... I need some sleep... Is 6 in the morning here... I`ll let you know.
Thanks Again.

[pansament]

Hello again...

When I tested new files I was tired. All repairs was gone and are gone from that point.
Every thing was fine because my dashboard showing data from cache...
After page and android app refresh I get "Entity not found" on my dashboard.
When I search for "weatherxm" in entities I only find "sensor.weatherxm_sensor" from RESTful integration with atributes from sensors.yaml but not sensors as entities.
Searched on documentations of home assistant new Templates how to get sensors from atributes but did not find anything.

So... Need help to get entities from weatherxm.

Thanks again for everything.

LE: After more debug I found that I had a "template:" block in my configuration.yam. Merged that block in templates.yaml and now everything is working as it should.

Sorry for creating new comment on this issue but maybe it will help others who don`t look for obvious problems on their systems.

I am very happy and satisfied that everything is working now.

[Anashost]

Glad you got it sorted.
My advice is to start using templates and sensors in more advanced way, to make things organized and easy to find and edit in the future.

So instead of:

sensor: !include sensors.yaml
template: !include templates.yaml

Use:

sensor: !include_dir_merge_list sensors/
template: !include_dir_merge_list templates/

Now create sensors and templates folders in /homeassistant/

And then create your templates and senors files separately and put then inside these folders.

Example: