---
title: "Script Syntax"
description: "Documentation for the Home Assistant Script Syntax."
redirect_from: /getting-started/scripts/
---
Scripts are a sequence of actions that Home Assistant will execute. Scripts are available as an entity through the standalone [Script component] but can also be embedded in [automations] and [Alexa/Amazon Echo] configurations.
The script syntax basic structure is a list of key/value maps that contain actions. If a script contains only 1 action, the wrapping list can be omitted.
```yaml
# Example script integration containing script syntax
script:
example_script:
sequence:
# This is written using the Script Syntax
- service: light.turn_on
data:
entity_id: light.ceiling
- service: notify.notify
data:
message: 'Turned on the ceiling light!'
```
### Call a Service
The most important one is the action to call a service. This can be done in various ways. For all the different possibilities, have a look at the [service calls page].
```yaml
- alias: Bedroom lights on
service: light.turn_on
data:
entity_id: group.bedroom
brightness: 100
```
#### Activate a Scene
Scripts may also use a shortcut syntax for activating scenes instead of calling the `scene.turn_on` service.
```yaml
- scene: scene.morning_living_room
```
### Test a Condition
While executing a script you can add a condition to stop further execution. When a condition does not return `true`, the script will stop executing. There are many different conditions which are documented at the [conditions page].
```yaml
# If paulus is home, continue to execute the script below these lines
- condition: state
entity_id: device_tracker.paulus
state: 'home'
```
### Delay
Delays are useful for temporarily suspending your script and start it at a later moment. We support different syntaxes for a delay as shown below.
```yaml
# Waits 1 hour
- delay: '01:00'
```
```yaml
# Waits 1 minute, 30 seconds
- delay: '00:01:30'
```
```yaml
# Waits 1 minute
- delay:
# Supports milliseconds, seconds, minutes, hours, days
minutes: 1
```
{% raw %}
```yaml
# Waits however many seconds input_number.second_delay is set to
- delay:
# Supports milliseconds, seconds, minutes, hours, days
seconds: "{{ states('input_number.second_delay') | int }}"
```
{% endraw %}
{% raw %}
```yaml
# Waits however many minutes input_number.minute_delay is set to
# Valid formats include HH:MM and HH:MM:SS
- delay: "{{ states('input_number.minute_delay') | multiply(60) | timestamp_custom('%H:%M:%S',False) }}"
```
{% endraw %}
### Wait
Wait until some things are complete. We support at the moment `wait_template` for waiting until a condition is `true`, see also on [Template-Trigger](/docs/automation/trigger/#template-trigger). It is possible to set a timeout after which the script will continue its execution if the condition is not satisfied. Timeout has the same syntax as `delay`.
{% raw %}
```yaml
# Wait until media player have stop the playing
- wait_template: "{{ is_state('media_player.floor', 'stop') }}"
```
{% endraw %}
{% raw %}
```yaml
# Wait for sensor to trigger or 1 minute before continuing to execute.
- wait_template: "{{ is_state('binary_sensor.entrance', 'on') }}"
timeout: '00:01:00'
```
{% endraw %}
When using `wait_template` within an automation `trigger.entity_id` is supported for `state`, `numeric_state` and `template` triggers, see also [Available-Trigger-Data](/docs/automation/templating/#available-trigger-data).
{% raw %}
```yaml
- wait_template: "{{ is_state(trigger.entity_id, 'on') }}"
```
{% endraw %}
It is also possible to use dummy variables, e.g., in scripts, when using `wait_template`.
{% raw %}
```yaml
# Service call, e.g., from an automation.
- service: script.do_something
data_template:
dummy: input_boolean.switch
# Inside the script
- wait_template: "{{ is_state(dummy, 'off') }}"
```
{% endraw %}
You can also get the script to abort after the timeout by using optional `continue_on_timeout`
{% raw %}
```yaml
# Wait until a valve is < 10 or abort after 1 minute.
- wait_template: "{{ state_attr('climate.kitchen', 'valve')|int < 10 }}"
timeout: '00:01:00'
continue_on_timeout: 'false'
```
{% endraw %}
Without `continue_on_timeout` the script will always continue.
### Fire an Event
This action allows you to fire an event. Events can be used for many things. It could trigger an automation or indicate to another integration that something is happening. For instance, in the below example it is used to create an entry in the logbook.
```yaml
- event: LOGBOOK_ENTRY
event_data:
name: Paulus
message: is waking up
entity_id: device_tracker.paulus
domain: light
```
You can also use event_data_template to fire an event with custom data. This could be used to pass data to another script awaiting
an event trigger.
{% raw %}
```yaml
- event: MY_EVENT
event_data_template:
name: myEvent
customData: "{{ myCustomVariable }}"
```
{% endraw %}
### Raise and Consume Custom Events
The following automation shows how to raise a custom event called `event_light_state_changed` with `entity_id` as the event data. The action part could be inside a script or an automation.
{% raw %}
```yaml
- alias: Fire Event
trigger:
- platform: state
entity_id: switch.kitchen
to: 'on'
action:
- event: event_light_state_changed
event_data:
state: 'on'
```
{% endraw %}
The following automation shows how to capture the custom event `event_light_state_changed`, and retrieve corresponding `entity_id` that was passed as the event data.
{% raw %}
```yaml
- alias: Capture Event
trigger:
- platform: event
event_type: event_light_state_changed
action:
- service: notify.notify
data_template:
message: "kitchen light is turned {{ trigger.event.data.state }}"
```
{% endraw %}
### Repeat a Group of Actions
This action allows you to repeat a sequence of other actions. Nesting is fully supported.
There are three ways to control how many times the sequence will be run.
#### Counted Repeat
This form accepts a count value. The value may be specified by a template, in which case
the template is rendered when the repeat step is reached.
{% raw %}
```yaml
script:
flash_light:
mode: restart
sequence:
- service: light.turn_on
data_template:
entity_id: "light.{{ light }}"
- repeat:
count: "{{ count|int * 2 - 1 }}"
sequence:
- delay: 2
- service: light.toggle
data_template:
entity_id: "light.{{ light }}"
flash_hallway_light:
sequence:
- service: script.flash_light
data:
light: hallway
count: 3
```
{% endraw %}
#### While Loop
This form accepts a list of conditions (see [conditions page] for available options) that are evaluated _before_ each time the sequence
is run. The sequence will be run _as long as_ the condition(s) evaluate to true.
{% raw %}
```yaml
script:
do_something:
sequence:
- service: script.get_ready_for_something
- alias: Repeat the sequence AS LONG AS the conditions are true
repeat:
while:
- condition: state
entity_id: input_boolean.do_something
state: 'on'
# Don't do it too many times
- condition: template
value_template: "{{ repeat.index <= 20 }}"
sequence:
- service: script.something
```
{% endraw %}
#### Repeat Until
This form accepts a list of conditions that are evaluated _after_ each time the sequence
is run. Therefore the sequence will always run at least once. The sequence will be run
_until_ the condition(s) evaluate to true.
{% raw %}
```yaml
automation:
- trigger:
- platform: state
entity_id: binary_sensor.xyz
to: 'on'
condition:
- condition: state
entity_id: binary_sensor.something
state: 'off'
mode: single
action:
- alias: Repeat the sequence UNTIL the conditions are true
repeat:
sequence:
# Run command that for some reason doesn't always work
- service: shell_command.turn_something_on
# Give it time to complete
- delay:
milliseconds: 200
until:
# Did it work?
- condition: state
entity_id: binary_sensor.something
state: 'on'
```
{% endraw %}
#### Repeat Loop Variable
A variable named `repeat` is defined within the repeat action (i.e., it is available inside `sequence`, `while` & `until`.)
It contains the following fields:
field | description
-|-
`first` | True during the first iteration of the repeat sequence
`index` | The iteration number of the loop: 1, 2, 3, ...
`last` | True during the last iteration of the repeat sequence, which is only valid for counted loops
### Choose a Group of Actions
This action allows you to select a sequence of other actions from a list of sequences.
Nesting is fully supported.
Each sequence is paired with a list of conditions (see [conditions page] for available options.) The first sequence whose conditions are all true will be run.
An optional `default` sequence can be included which will be run if none of the sequences from the list are run.
{% raw %}
```yaml
automation:
- trigger:
- platform: state
entity_id: binary_sensor.motion
mode: queued
action:
- choose:
# IF motion detected
- conditions:
- condition: template
value_template: "{{ trigger.to_state.state == 'on' }}"
sequence:
- service: script.turn_on
entity_id:
- script.slowly_turn_on_front_lights
- script.announce_someone_at_door
# ELSE (i.e., motion stopped)
default:
- service: light.turn_off
entity_id: light.front_lights
```
{% endraw %}
[Script component]: /integrations/script/
[automations]: /getting-started/automation-action/
[Alexa/Amazon Echo]: /integrations/alexa/
[service calls page]: /getting-started/scripts-service-calls/
[conditions page]: /getting-started/scripts-conditions/