Home Assistant

Home Assistant Configuration

You are working inside a Home Assistant environment. The configuration directory is mounted at /homeassistant.

File Layout

/homeassistant/
  configuration.yaml    # Main config, loads other files via includes
  automations.yaml      # UI-created automations (list format)
  scripts.yaml          # UI-created scripts (list format)
  scenes.yaml           # UI-created scenes (list format)
  secrets.yaml          # Secret values (passwords, tokens, API keys)
  customize.yaml        # Entity customizations
  packages/             # Package-based config (self-contained bundles)
  blueprints/           # Automation and script blueprints
  custom_components/    # HACS and manual custom integrations
  www/                  # Static files served at /local/
  dashboards/           # Lovelace dashboard YAML files

Key Rules

• Never expose secrets. Use !secret key_name references instead of hardcoding values. Secrets are defined in secrets.yaml.
• Validate before restarting. Always run ha core check after config changes. Only suggest a restart if validation passes.
• Preserve UI-managed files. Files like automations.yaml, scripts.yaml, and scenes.yaml use a list format managed by the UI. Edits must preserve this format (list of objects with id, alias, etc.).
• Use packages for organization. Packages under packages/ bundle related entities together. Each package is a self-contained YAML file that mirrors the top-level config structure.

YAML Syntax

Home Assistant extends YAML with special constructors:

Jinja2 Templates

Templates use Jinja2 syntax inside YAML values:

sensor:
  - platform: template
    sensors:
      friendly_temp:
        value_template: "{{ states('sensor.temperature') | float | round(1) }}"
        unit_of_measurement: "F"

Common template objects: states('entity_id'), state_attr('entity_id', 'attribute'), is_state('entity_id', 'value'), now(), as_timestamp().

Automations

Manual automations in configuration.yaml or packages use the mapping format:

automation:
  - alias: "Turn on lights at sunset"
    trigger:
      - platform: sun
        event: sunset
        offset: "-00:30:00"
    condition:
      - condition: state
        entity_id: binary_sensor.someone_home
        state: "on"
    action:
      - service: light.turn_on
        target:
          entity_id: light.living_room

Available CLI

The ha command provides access to the Home Assistant CLI: