Agent Skills: Home Assistant Best Practices

Home Assistant Best Practices

Core principle: Use native Home Assistant constructs wherever possible. Templates bypass validation, fail silently at runtime, and make debugging opaque.

If task scope is unclear, route first with: homeassistant-router/SKILL.md. For scripted bulk execution, use: homeassistant-ops/SKILL.md. For interactive runtime CLI execution, use: home-assistant-cli-ops/SKILL.md.

Decision Workflow

Follow this sequence when creating any automation:

0. Gate: modifying existing config?

If your change affects entity IDs or cross-component references — renaming entities, replacing template sensors with helpers, converting device triggers, or restructuring automations — read references/safe-refactoring.md first. That reference covers impact analysis, device-sibling discovery, and post-change verification. Complete its workflow before proceeding.

Steps 1-5 below apply to new config or pattern evaluation.

1. Check for native condition/trigger

Before writing any template, check references/automation-patterns.md for native alternatives.

Common substitutions:

• {{ states('x') | float > 25 }} → numeric_state condition with above: 25
• {{ is_state('x', 'on') and is_state('y', 'on') }} → condition: and with state conditions
• {{ now().hour >= 9 }} → condition: time with after: "09:00:00"
• wait_template: "{{ is_state(...) }}" → wait_for_trigger with state trigger (caveat: different behavior when state is already true — see references/safe-refactoring.md#trigger-restructuring)

2. Check for built-in helper

Before creating a template sensor, check references/helper-selection.md.

Common substitutions:

• Sum/average multiple sensors → min_max integration
• Binary any-on/all-on logic → group helper
• Rate of change → derivative integration
• Cross threshold detection → threshold integration
• Consumption tracking → utility_meter helper

3. Select correct automation mode

Default single mode is often wrong. See references/automation-patterns.md#automation-modes.

| Scenario | Mode | |----------|------| | Motion light with timeout | restart | | Sequential processing (door locks) | queued | | Independent per-entity actions | parallel | | One-shot notifications | single |

4. Use entity_id over device_id

device_id breaks when devices are re-added. See references/device-control.md.

Exception: Zigbee2MQTT autodiscovered device triggers are acceptable.

5. For Zigbee buttons/remotes

• ZHA: Use event trigger with device_ieee (persistent)
• Z2M: Use device trigger (autodiscovered) or mqtt trigger

See references/device-control.md#zigbee-buttonremote-patterns.

Critical Anti-Patterns

| Anti-pattern | Use instead | Why | Reference | |---|---|---|---| | condition: template with float > 25 | condition: numeric_state | Validated at load, not runtime | references/automation-patterns.md#native-conditions | | wait_template: "{{ is_state(...) }}" | wait_for_trigger with state trigger | Event-driven, not polling; waits for change (see references/safe-refactoring.md#trigger-restructuring for semantic differences) | references/automation-patterns.md#wait-actions | | device_id in triggers | entity_id (or device_ieee for ZHA) | device_id breaks on re-add | references/device-control.md#entity-id-vs-device-id | | mode: single for motion lights | mode: restart | Re-triggers must reset the timer | references/automation-patterns.md#automation-modes | | Template sensor for sum/mean | min_max helper | Declarative, handles unavailable states | references/helper-selection.md#numeric-aggregation | | Template binary sensor with threshold | threshold helper | Built-in hysteresis support | references/helper-selection.md#threshold | | Renaming entity IDs without impact analysis | Follow references/safe-refactoring.md workflow | Renames break dashboards, scripts, and scenes silently | references/safe-refactoring.md#entity-renames |

Reference Files

Read these when you need detailed information:

| File | When to read | Key sections | |------|--------------|--------------| | references/safe-refactoring.md | Renaming entities, replacing helpers, restructuring automations, or any modification to existing config | #universal-workflow, #entity-renames, #helper-replacements, #trigger-restructuring | | references/automation-patterns.md | Writing triggers, conditions, waits, or choosing automation modes | #native-conditions, #trigger-types, #wait-actions, #automation-modes, #ifthen-vs-choose, #trigger-ids | | references/helper-selection.md | Deciding whether to use a built-in helper vs template sensor | #numeric-aggregation, #rate-and-change, #time-based-tracking, #counting-and-timing, #scheduling, #entity-grouping, #decision-matrix | | references/template-guidelines.md | Confirming templates ARE appropriate for a use case | #when-templates-are-appropriate, #when-to-avoid-templates, #template-sensor-best-practices, #common-patterns, #error-handling | | references/device-control.md | Writing service calls, Zigbee button automations, or using target: | #entity-id-vs-device-id, #service-calls-best-practices, #zigbee-buttonremote-patterns, #domain-specific-patterns | | references/examples.yaml | Need compound examples combining multiple best practices | — |