Home Assistant Entities

When to Use This Skill

Use this skill when...	Use ha-automations instead when...
Understanding entity domains	Creating automation rules
Customizing entities	Working with triggers/actions
Creating template sensors	Writing automation conditions
Setting up groups	Working with scripts/scenes
Working with device classes	Handling events

Entity ID Structure

domain.object_id

Examples:

• light.living_room_ceiling
• sensor.outdoor_temperature
• binary_sensor.front_door_contact
• switch.garden_irrigation

Common Domains

Domain	Description	Example
light	Lighting control	light.kitchen
switch	On/off switches	switch.outlet
sensor	Numeric sensors	sensor.temperature
binary_sensor	On/off sensors	binary_sensor.motion
climate	HVAC control	climate.thermostat
cover	Blinds, garage doors	cover.garage
lock	Door locks	lock.front_door
media_player	Media devices	media_player.tv
camera	Camera feeds	camera.front_yard
vacuum	Robot vacuums	vacuum.roomba
fan	Fan control	fan.bedroom
alarm_control_panel	Alarm systems	alarm_control_panel.home
person	People tracking	person.john
device_tracker	Device location	device_tracker.phone
weather	Weather info	weather.home
input_boolean	Virtual toggle	input_boolean.guest_mode
input_number	Virtual number	input_number.target_temp
input_select	Virtual dropdown	input_select.house_mode
input_text	Virtual text	input_text.message
input_datetime	Virtual date/time	input_datetime.alarm
input_button	Virtual button	input_button.reset
automation	Automations	automation.motion_light
script	Scripts	script.morning_routine
scene	Scenes	scene.movie_night
group	Entity groups	group.all_lights
timer	Countdown timers	timer.laundry
counter	Counters	counter.guests
zone	Geographic zones	zone.home
sun	Sun position	sun.sun

For complete device class tables (binary sensor and sensor), see REFERENCE.md.

Entity Customization

customize.yaml

# Single entity
light.living_room:
  friendly_name: "Living Room Light"
  icon: mdi:ceiling-light

# Binary sensor
binary_sensor.front_door:
  friendly_name: "Front Door"
  device_class: door

# Sensor
sensor.outdoor_temperature:
  friendly_name: "Outdoor Temperature"
  device_class: temperature
  unit_of_measurement: "°C"

Glob Customization

customize_glob:
  "light.*_ceiling":
    icon: mdi:ceiling-light

  "sensor.*_temperature":
    device_class: temperature
    unit_of_measurement: "°C"

  "binary_sensor.*_motion":
    device_class: motion

Template Sensors

template:
  - sensor:
      # Simple state
      - name: "Average Temperature"
        unit_of_measurement: "°C"
        device_class: temperature
        state: >-
          {{ ((states('sensor.living_room_temp') | float +
               states('sensor.bedroom_temp') | float +
               states('sensor.kitchen_temp') | float) / 3) | round(1) }}

      # With attributes
      - name: "Power Usage"
        unit_of_measurement: "W"
        device_class: power
        state: "{{ states('sensor.energy_meter_power') }}"
        attributes:
          cost_per_hour: >-
            {{ (states('sensor.energy_meter_power') | float * 0.15 / 1000) | round(2) }}

      # Availability
      - name: "Solar Power"
        unit_of_measurement: "W"
        device_class: power
        state: "{{ states('sensor.inverter_power') }}"
        availability: "{{ states('sensor.inverter_power') != 'unavailable' }}"

For template binary sensors, switches, buttons, numbers, groups, utility meters, counters, and timers, see REFERENCE.md.

State Attributes

Common Attributes

Domain	Common Attributes
light	brightness, color_temp, rgb_color, hs_color, effect
climate	temperature, current_temperature, hvac_action, preset_mode
media_player	volume_level, media_title, media_artist, source
cover	current_position, current_tilt_position
weather	temperature, humidity, pressure, wind_speed, forecast
person	source, latitude, longitude, gps_accuracy
sun	elevation, azimuth, next_rising, next_setting

Accessing Attributes

# In templates
{{ state_attr('light.living_room', 'brightness') }}
{{ state_attr('climate.thermostat', 'current_temperature') }}
{{ state_attr('sun.sun', 'elevation') }}

# In conditions
condition:
  - condition: numeric_state
    entity_id: light.living_room
    attribute: brightness
    above: 100

Quick Reference

State Functions

Function	Description	Example
states('entity')	Get state	states('sensor.temp')
state_attr('entity', 'attr')	Get attribute	state_attr('light.x', 'brightness')
is_state('entity', 'value')	Check state	is_state('light.x', 'on')
is_state_attr('entity', 'attr', 'val')	Check attribute	is_state_attr('climate.x', 'hvac_action', 'heating')
states.domain	All entities in domain	states.light
expand('group.x')	Expand group members	expand('group.all_lights')

Agentic Optimizations

Context	Command
Find entity usage	grep -r "entity_id:" config/ --include="*.yaml"
List customizations	grep -rA2 "^[a-z_]*\\..*:" config/customize.yaml
Find template sensors	grep -rB2 "platform: template" config/ --include="*.yaml"
Find groups	grep -rA5 "^group:" config/ --include="*.yaml"
List domains used	grep -roh "[a-z_]*\\." config/ --include="*.yaml" | sort -u