Home Assistant YAML Tips: 15 Tricks I Learned After 60 Automations

I have 60+ automations across 11 package files controlling a 700+ entity system. Every tip here comes from something that either saved me real time or cost me an afternoon of debugging. No theory — just the things that actually matter when you're writing YAML every week.

1. YAML Anchors Eliminate Duplicate Blocks

If you're copy-pasting the same condition or action across multiple automations, you're doing it wrong. YAML anchors let you define a block once and reuse it.

Define an anchor with `&name`, reference it with `*name`, and merge mapping keys with `<<:`.

Define once at the top of your package

.common_conditions:

home_and_awake: &home_and_awake

entity_id: person.baily

state: "home"

entity_id: input_boolean.sleep_mode

state: "off"

automation:

alias: "Kitchen Motion Lights"

trigger:

entity_id: binary_sensor.kitchen_motion

to: "on"

condition: *home_and_awake

action:

target:

entity_id: light.kitchen

alias: "Hallway Motion Lights"

trigger:

entity_id: binary_sensor.hallway_motion

to: "on"

condition: *home_and_awake

action:

target:

entity_id: light.hallway

Two automations, one shared condition block. Change it in one place, both update. This is native YAML — no HA-specific feature required.

2. Jinja2 Templates Make Automations Dynamic

Templates let you compute values at runtime instead of hardcoding them. The most common use: brightness that changes based on time of day.

action:

target:

entity_id: light.hallway

data:

brightness: >

{% set hour = now().hour %}

{% if hour >= 23 or hour < 5 %}25

{% elif hour >= 5 and hour < 7 %}77

{% elif hour >= 7 and hour < 21 %}178

{% else %}102{% endif %}

The `>` after `brightness:` tells YAML this is a multi-line scalar. HA evaluates it as a Jinja2 template and returns the number. You can also use templates in `message:` fields for notifications, `data:` for service calls, and even `condition:` blocks with `value_template`.

condition:

value_template: "{{ states('sensor.front_door_battery') | int < 20 }}"

3. secrets.yaml Keeps Credentials Out of Your Config

Never hardcode API keys, passwords, or webhook URLs in your automations. Home Assistant reads `secrets.yaml` from your config directory and substitutes values anywhere you use `!secret`.

/config/secrets.yaml

pushover_api_key: "abc123def456"

camera_password: "mysecretpass"

webhook_camera_front: "a8f3e2b1-unique-id-here"

In your automation

action:

data:

message: "Motion detected"

data:

api_key: !secret pushover_api_key

This also means you can share your entire config on GitHub without leaking credentials. Just add `secrets.yaml` to `.gitignore`.

4. !include and !include_dir_named Split Your Config

As your config grows, one massive file becomes unmanageable. HA supports several include strategies:

Include a single file

automation: !include automations.yaml

Include a directory — each file becomes a named key

homeassistant:

packages: !include_dir_named packages/

Include a directory — each file is a list item merged together

automation: !include_dir_merge_list automations/

Include a directory — each file is a dict merged together

sensor: !include_dir_merge_named sensors/

I use `!include_dir_named packages/` for all my automations. Each YAML file in `packages/` is a self-contained module with its own automations, helpers, timers, and scripts. See my [packages guide](/blog/home-assistant-packages-yaml-guide) for the full setup.

5. Automation IDs: Always Set Them

Every automation needs a unique `id:` field. Without it, HA can't track the automation in the UI — you lose access to the trace debugger, you can't enable/disable it from the dashboard, and the automation editor won't show it.

automation:

alias: "Garage Auto-Close Warning"

trigger:

...

Use descriptive, snake_case IDs. I prefix mine with the package name: `garage_auto_close`, `camera_push_front_motion`, `alarm_triggered_response`. If two automations share an ID, only one loads — and HA won't tell you.

6. mode: Controls What Happens on Re-Trigger

By default, automations use `mode: single` — if the automation is already running, a new trigger is ignored. This is often not what you want.

automation:

alias: "Hallway Motion Light"

mode: restart # Kill current run, start fresh

trigger:

entity_id: binary_sensor.hallway_motion

to: "on"

action:

target:

entity_id: light.hallway

target:

entity_id: light.hallway

The four modes:

If your motion light stays on forever or your notification fires twice, check your `mode:` first.

7. Condition Shortcuts Save Lines

You don't always need the verbose `condition:` block. HA supports shorthand for common checks.

Verbose

condition:

entity_id: input_boolean.notifications_enabled

state: "on"

Shorthand — same result

condition: "{{ is_state('input_boolean.notifications_enabled', 'on') }}"

For combining conditions:

AND (default — all must be true)

condition:

entity_id: person.baily

state: "home"

after: "22:00:00"

OR — at least one must be true

condition:

conditions:

entity_id: cover.garage_bay_1

state: "open"

entity_id: cover.garage_bay_2

state: "open"

NOT — must be false

condition:

conditions:

entity_id: alarm_control_panel.panel

state: "triggered"

8. Trigger Variables Give Context to Actions

When an automation has multiple triggers, you need to know which one fired. Trigger variables solve this.

automation:

alias: "Door Opened Notification"

trigger:

entity_id: binary_sensor.front_door

to: "on"

id: front_door

entity_id: binary_sensor.back_door

to: "on"

id: back_door

action:

data:

title: "Door Opened"

message: "{{ trigger.id }} opened at {{ now().strftime('%H:%M') }}"

The `trigger.id` field is a string you assign to each trigger. Inside actions, you also get `trigger.entity_id`, `trigger.to_state`, `trigger.from_state`, and other context depending on the trigger platform. This eliminates the need for separate automations per door.

9. choose: Branches Your Logic

Instead of writing three separate automations for different scenarios, use `choose:` to branch within one.

action:

after: "06:00:00"

before: "09:00:00"

sequence:

target:

entity_id: media_player.kitchen

data:

message: "Good morning. Garage is {{ states('cover.garage_bay_1') }}."

after: "22:00:00"

sequence:

target:

entity_id: light.hallway

data:

brightness: 25

default:

target:

entity_id: light.hallway

data:

brightness: 178

`choose:` evaluates conditions top-down and runs the first match. The `default:` block runs if nothing matches. This is Home Assistant's version of if/elif/else.

10. wait_for_trigger Pauses Until Something Happens

Sometimes you need an automation to wait for a real-world event before continuing. `wait_for_trigger` pauses execution until a condition is met or a timeout expires.

action:

data:

title: "Garage Open"

message: "Bay 1 has been open 10 minutes. Closing in 2 minutes."

data:

actions:

title: "Keep Open"

event_type: mobile_app_notification_action

event_data:

action: KEEP_OPEN

timeout: "00:02:00"

continue_on_timeout: true

then:

target:

entity_id: cover.garage_bay_1

This sends a notification, waits 2 minutes for the user to tap "Keep Open," and closes the garage if they don't respond. `wait.trigger` is `none` when the timeout fires without a trigger.

11. Use person, Not device_tracker

`device_tracker` entities represent individual tracking methods — your phone's WiFi, Bluetooth, GPS, etc. A single person might have 2-3 device trackers, and they can disagree about whether you're home.

`person` entities combine all device trackers for one individual and apply HA's presence logic. Always use `person` for presence-based automations.

Wrong — depends on one tracking method

trigger:

entity_id: device_tracker.phone_wifi

to: "home"

Right — combines all tracking sources

trigger:

entity_id: person.baily

to: "home"

If your presence automations are unreliable, check Developer Tools > States and look at your `person` entity's source list. You might have a stale device tracker dragging it to "away."

12. service vs. action: Know the Difference

Starting in HA 2024.x, the `service:` key in actions was renamed to `action:`. Both work, but you'll see both in examples online and it causes confusion.

Old syntax (still works)

action:

target:

entity_id: light.kitchen

New syntax (2024+)

action:

target:

entity_id: light.kitchen

They are functionally identical. `service:` is not deprecated and will keep working. But if you're starting fresh or refactoring, `action:` is the current convention. Just be consistent within each file — mixing them won't break anything but it looks messy.

13. Common YAML Syntax Errors (and How to Fix Them)

These three mistakes account for 90% of the YAML errors I've debugged.

**Indentation errors.** YAML is whitespace-sensitive. Every nested level must be exactly 2 spaces (convention, not spec — but HA expects consistency). Tabs will break everything silently.

Broken — mixed indentation

automation:

entity_id: binary_sensor.door

action:

**Unquoted colons.** Any value containing a colon needs quotes. This burns people with timestamps and messages.

Broken — colon in an unquoted string

message: Warning: door is open

Fixed

message: "Warning: door is open"

**Booleans as strings.** YAML treats `on`, `off`, `yes`, `no`, `true`, `false` as booleans. If you mean the string `"on"`, quote it.

This compares to boolean True, not string "on"

state: on

This compares to the string "on" — what you want

state: "on"

If your automation never triggers and the YAML looks fine, check that your state comparisons are quoted.

14. Validate Config Before You Restart

A YAML error in any package file will prevent Home Assistant from starting. Always validate before you restart.

**From the UI:** Go to Developer Tools > YAML > Check Configuration. This parses all your YAML files and reports errors without restarting.

**From the command line** (if you have SSH or terminal access):

ha core check

This runs the same validation. If it returns "Configuration is valid," you're safe to restart.

**From VS Code:** Install the Home Assistant Config Helper extension. It highlights syntax errors in real-time as you type and provides schema validation for known configuration keys.

I validate after every edit, before every restart. The 10 seconds it takes has saved me from plenty of 3-minute restart-crash-fix-restart cycles.

15. Use Traces in Developer Tools to Debug

When an automation doesn't do what you expect, don't guess — read the trace.

Go to **Developer Tools > Automations**, find your automation, and click **Traces**. Each run shows:

Trigger: state of binary_sensor.front_door changed to "on"

Condition: person.baily is "home" → PASS

Condition: input_boolean.notifications → FAIL (state: "off")

Result: Stopped at condition — no actions executed

If your automation ran but the notification didn't arrive, the trace will show you whether the `notify` service call succeeded or threw an error. If it never ran at all, the trace will show which condition blocked it.

You can also fire automations manually from Developer Tools > Services using `automation.trigger` — this bypasses conditions and runs the action sequence directly. Useful for testing the action chain without waiting for the real trigger.

The Boring Truth

Most YAML problems aren't interesting. They're a missing quote, a wrong indentation level, or a `mode: single` that silently swallows re-triggers. The tips above won't make your smart home feel like science fiction — but they'll stop you from losing afternoons to problems that have nothing to do with your actual automation logic.

Write clean YAML, validate before you restart, and read the traces when something breaks. That's 80% of the battle.

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*This post is part of [The Automated Home](/) — practical Home Assistant guides from a 700+ entity production system.*