Deprecation of legacy template entities in 2025.12

Which migration guide did you choose? There are 3 and each one is tailored towards possible existing configurations with step by step instructions on what to do.

I wasn’t given an option of three imgrations. I ran the action in the Developer Tools and it gave me two lines of code.

Then you haven’t looked at the guides I’m talking about that are linked in this post.

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I followed every step on this guide:

That is the custom integration. You’re asking questions that are answered in the official guides.

Well I looked through the official guide and I’m having trouble what lines of code need to be added or swapped. It’s not as straightforward for me at the very least so I tried the Migration tool so I could at least understand what needed to be deleted or added. I have no issue doing it manually, but I’m clearly not seeing the concept here.

The custom integration migration tool does everything for you, including add all the files. The only thing it does not do is remove the legacy configuration, which you have to do manually.

Let me ask this. I see all of the lines of code exported with the helper in the sensor.yaml file. Do I just need to add the template code sections for each sensor and then add that into my main configuration?

Got it. So I just need to delete the old data.

If you followed the directions on the custom integration, step 4 adds all the new template entities to your configuration.

Understood thank you. I wasn’t getting past step 3 because I needed to remove all of the older data since the guide didn’t list that out separately. All appears to be working now! Thank you for your help.

Removing is step 6

How is config file splitting achieved?
The information in Splitting up the configuration - Home Assistant seems not to be updated to the new template syntax

New and old was never covered in that documentation. That documentation provides examples of how to split up the config and it uses random integrations to show examples.

I’m confused here - need some help. Best I can tell I followed the recommendation provided verbatim, but I’m getting a "entity - ā€˜sensor…’ does not exist’ message in my configuration.yaml. See below

Here’s the recommendation from the system - think I added it as it states. What am I missing?

Should be safe to ignore the warning. It’s been stated multiple times in this thread that yaml parsers like VSCode haven’t been updated and throw false alerts.

EDIT: it’ll exist once you restart HA.

This guide seems very clear: https://jirkovynavody.cz/en/homeassistant/configuration/template-migration/ but it always refers to unique_id and this thread refers to default_entity_id (as do my HA warning messages/suggestions).
I do not know the difference nor what to change mine to. This thread (I blame myself) does not make it clear to me. I currently have all these in configuration.yaml but intend to make these changes and move the template sensors to the seperate templates.yaml. i think i read somewhere historystats should stay in configuration.yaml

I tried to find relevant data regarding the migration on https://www.home-assistant.io/docs/configuration/ but could not find any.

Any suggestions? many thanks!

Why are you following some random guide? That guide is making massive assumptions without actually knowing what the key translations are.

The code provided by the deprecation repair is what you should be using, nothing else.

Use the documentation linked in the top of this post. There are 3 guides, choose the guide based on your current configuration.

as i politely pointed out, this guide did not make it clear to me. I also clearly said that it is my fault. This is written in the form of a forum post rather than a guide or in the docs made available on the home-assistant.io website. (ignore the other link as anything else clearly brings out allergic reactions.
The code suggested is useful (even if the formatting is then all messed up, if i copy paste from the message in home-assistant), but, given we have many sensors, it would be nice to gain better understanding. The question was simple and woudl help people understand the underlying rational and learn what should be done now.

Calling anything ā€œrandomā€ is a little rude given so many people put effort into this project but whatever.

I’m frustrated because I can see you did not click on the link, that tells me you haven’t used the guides in the official documentation on home-assistant.io.

Here’s the link again.

Please try to use those guides before asking questions. And if you have problems, mention which guide you’re using (there is 3 of them) and what you’re confused about.


Sorry, it’s not rude. That person created a guide off incorrect information. It is a random guide and it likely gets things wrong.