Automation always fails with Message malformed: extra keys not allowed @ data['0'] – how to debug

[shrewd sluice]

Hi all,

I’m struggling with an automation that always fails to load with this error:

Message malformed: extra keys not allowed @ data['0']

The problem is that Home Assistant does not tell me WHICH key is invalid, so I’m stuck guessing.

Context:

• Home Assistant Core
• automations.yaml in YAML mode
• Other automations in the same file work fine
• notify.mobile_app_* works in other automations
• This error appears even when I remove triggers and conditions

This automation fails:

- id: highest_humidity_room_manual_test
  alias: TEST – Highest humidity room (manual)
  mode: single

  actions:
    - action: notify.mobile_app_justy2
      data:
        title: "TEST humidity"
        message: >
          {% set ns = namespace(room='', value=0) %}

          {% set v = states('sensor.adela_humidity') | float(0) %}
          {% if v > ns.value %}{% set ns.room = 'Adela' %}{% set ns.value = v %}{% endif %}

          {% set v = states('sensor.john_humidity') | float(0) %}
          {% if v > ns.value %}{% set ns.room = 'John' %}{% set ns.value = v %}{% endif %}

          {% set v = states('sensor.living_room_humidity') | float(0) %}
          {% if v > ns.value %}{% set ns.room = 'Living room' %}{% set ns.value = v %}{% endif %}

          {% set v = states('sensor.bedroom_humidity') | float(0) %}
          {% if v > ns.value %}{% set ns.room = 'Bedroom' %}{% set ns.value = v %}{% endif %}

          {% set v = states('sensor.storage_humidity') | float(0) %}
          {% if v > ns.value %}{% set ns.room = 'Storage' %}{% set ns.value = v %}{% endif %}

          Result: {{ ns.room }} ({{ ns.value }} %)

Questions:

1. Is there any way to get MORE DETAILED validation errors than just data['0']?
2. Is there a recommended way to TEST automations schema-wise before runtime?
3. Is this error usually caused by:
   • missing required keys (like triggers),
   • mixing old/new automation syntax,
   • or something else entirely?

Any advice on how to debug these schema errors properly would be really appreciated.

[naive hearth]

Are you trying to create an automation without triggers?

[shrewd sluice]

First I tried to create trigger once per hour but now I just wanted to try manual so yea

[naive hearth]

An automation needs a trigger section

If you don't want a trigger, you can create a script

[shrewd sluice]

I wanted to have trigger once per hour but when getting errors i wanted to try if trigger isnt the issue :/

[naive hearth]

At least add

  triggers: []

[shrewd sluice]

wellp still getting Message malformed: extra keys not allowed @ data['0'] even after adding ```yaml
triggers: []

[naive hearth]

I've tested it in the GUI (I'm on mobile right now) and I was able to save this automation without issues

alias: TEST – Highest humidity room (manual)
mode: single
triggers: []
actions:
  - action: notify.mobile_app_justy2
    data:
      title: TEST humidity
      message: >
        {% set ns = namespace(room='', value=0) %}

        {% set v = states('sensor.adela_humidity') | float(0) %} {% if v >
        ns.value %}{% set ns.room = 'Adela' %}{% set ns.value = v %}{% endif %}

        {% set v = states('sensor.john_humidity') | float(0) %} {% if v >
        ns.value %}{% set ns.room = 'John' %}{% set ns.value = v %}{% endif %}

        {% set v = states('sensor.living_room_humidity') | float(0) %} {% if v >
        ns.value %}{% set ns.room = 'Living room' %}{% set ns.value = v %}{%
        endif %}

        {% set v = states('sensor.bedroom_humidity') | float(0) %} {% if v >
        ns.value %}{% set ns.room = 'Bedroom' %}{% set ns.value = v %}{% endif
        %}

        {% set v = states('sensor.storage_humidity') | float(0) %} {% if v >
        ns.value %}{% set ns.room = 'Storage' %}{% set ns.value = v %}{% endif
        %}

        Result: {{ ns.room }} ({{ ns.value }} %)
description: ""

[shrewd sluice]

well problem I found was that ```yaml

• id:

However is there any option to detect more from error? like what HA cannot resovle?

[naive hearth]

Looks like this in automations.yaml

- id: '1766346947217'
  alias: TEST – Highest humidity room (manual)
  description: ''
  triggers: []
  actions:
  - action: notify.mobile_app_justy2
    data:
      title: TEST humidity
      message: '{% set ns = namespace(room='''', value=0) %}

        {% set v = states(''sensor.adela_humidity'') | float(0) %} {% if v > ns.value
        %}{% set ns.room = ''Adela'' %}{% set ns.value = v %}{% endif %}

        {% set v = states(''sensor.john_humidity'') | float(0) %} {% if v > ns.value
        %}{% set ns.room = ''John'' %}{% set ns.value = v %}{% endif %}

        {% set v = states(''sensor.living_room_humidity'') | float(0) %} {% if v >
        ns.value %}{% set ns.room = ''Living room'' %}{% set ns.value = v %}{% endif
        %}

        {% set v = states(''sensor.bedroom_humidity'') | float(0) %} {% if v > ns.value
        %}{% set ns.room = ''Bedroom'' %}{% set ns.value = v %}{% endif %}

        {% set v = states(''sensor.storage_humidity'') | float(0) %} {% if v > ns.value
        %}{% set ns.room = ''Storage'' %}{% set ns.value = v %}{% endif %}

        Result: {{ ns.room }} ({{ ns.value }} %)

        '
  mode: single

Well data[0] was an indication it was one of the keys on the top level of the automation

[shrewd sluice]

however in automations.yaml you see id but in gui you cannot insert it its bit weird

[naive hearth]

But it looks like a valid id to maybe just not in automations.yaml

Oh, you had this code in the YAML editor in the GUI?

It was not copied from automations.yaml

Then the error was the dash -

[shrewd sluice]

yep