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.

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 safe-refactoring 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 a purpose-specific, then generic native, trigger/condition

Since 2026.7 the default building blocks are purpose-specific triggers/conditions — <domain>.<name> keys (motion detected, battery low, door opened) with area/floor/label targets. Check for one that matches the intent first, then a generic native trigger/condition, and only then a template. See automation-patterns #purpose-specific-triggers--conditions-default-since-20267.

Common substitutions:

• List of individual sensor entities in a trigger → one purpose-specific trigger with an area/floor/label target:
• {{ 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 safe-refactoring #trigger-restructuring)

2. Check for built-in helper or Template Helper

Before creating a template sensor, check helper-selection.

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

If no built-in helper fits, use a Template Helper — not YAML. Create it via the HA config flow (programmatically or in the UI: Settings → Devices & Services → Helpers → Create Helper → Template). A flow-created helper is UI-editable; a template: YAML entry needs a template.reload and is not.

Write template: YAML when the user asks for it, when neither path is available, or when the config needs a key the flow has no field for — trigger-based templates and attributes: are the common ones. Then use managed YAML editing (yaml-only-integrations), not a hand-edit.

3. Select correct automation mode

Default single mode is often wrong. See automation-patterns #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 device-control.

Exception: Zigbee2MQTT autodiscovered device triggers are acceptable.

5. For buttons and remotes

• Any integration exposing an event.* entity: Use event.received targeting that entity — a normal entity, so it can be renamed and survives a re-add when the integration keeps a stable unique ID
• ZHA: No event entities — use an event trigger with device_ieee (persistent)
• Z2M: Event entities are experimental and off by default — use a device trigger (autodiscovered) or mqtt trigger

See device-control #buttonremote-patterns.

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Critical Anti-Patterns

Anti-pattern	Use instead	Why	Reference
condition: template with float > 25	condition: numeric_state	Validated at load, not runtime	automation-patterns #native-conditions
wait_template: "{{ is_state(...) }}"	wait_for_trigger with state trigger	Event-driven, not polling; waits for change (see safe-refactoring #trigger-restructuring for semantic differences)	automation-patterns #wait-actions
device_id in triggers	entity_id (or device_ieee for ZHA)	device_id breaks on re-add	device-control #entity-id-vs-device-id
mode: single for motion lights	mode: restart	Re-triggers must reset the timer	automation-patterns #automation-modes
enabled: false as a top-level key in automations.yaml	automation.turn_off (temporary) or entity registry disable (permanent)	Not a valid top-level key — rejected during schema validation; automation loads as unavailable	automation-patterns #disabling-automations
Template sensor for sum/mean	min_max helper	Declarative, handles unavailable states	helper-selection #numeric-aggregation
Template binary sensor with threshold	threshold helper	Built-in hysteresis support	helper-selection #threshold
Renaming entity IDs without impact analysis	Follow safe-refactoring workflow	Renames break dashboards, scripts, scenes, Config-Entry data, and storage dashboards silently	safe-refactoring #entity-renames
Renaming members of Config-Entry-based groups (UI groups) without updating membership	Update group membership via Options Flow after the registry rename	The entity registry rename does not update options.entities in the Config Entry — group silently breaks	safe-refactoring #config-entry-groups
Renaming entities used by Config-Entry integrations (Better/Generic Thermostat, Min/Max, Threshold) without patching Config-Entry data	Scan and patch core.config_entries data+options fields	These integrations store entity_ids in Config Entry — not updated by entity registry renames	safe-refactoring #config-entry-data--blind-spots-for-entity-registry-renames
template: sensor/binary sensor in YAML	Template Helper via the config flow	A flow helper reloads in place and stays UI-editable; a template: entry needs a config reload and does not. Exceptions are real — trigger-based templates and attributes: have no flow field	helper-selection #template-helpers
Editing .storage/ files or other HA internal state directly	Use the HA REST/WebSocket API to manage state and config entries	.storage/ files are HA's internal state database; direct edits bypass validation, risk corruption, and can be silently overwritten by HA	—
Writing raw YAML to configuration.yaml by hand for YAML-only integrations	Use managed YAML config editing with backup and validation	Unmanaged writes risk syntax errors, have no backup, and skip check_config — managed editing provides all three	yaml-only-integrations
Generating YAML snippets for automations/scripts/scenes	Use the HA config API to create automations/scripts programmatically	API calls validate config, avoid syntax errors, and don't require manual file edits or restarts	automation-patterns, examples.yaml
Telling user to edit configuration.yaml for integrations	Direct user to Settings > Devices & Services in the HA UI	Most integrations are UI-configured; YAML integration config is rare and integration-specific	—
Referring to HA "add-ons"	Use the term "Apps"	HA renamed add-ons to Apps in 2026.2 — "Apps are standalone applications that run alongside Home Assistant"	—
vacuum.send_command with vendor room IDs	vacuum.clean_area with HA area_id (if segments are mapped)	Uses native HA areas, works across integrations — but requires segment-to-area mapping in entity settings first	device-control #vacuum-control
Using color_temp (mireds) in light actions	Use color_temp_kelvin	The color_temp parameter was removed in 2026.3; only Kelvin is supported	device-control #lights
Person/Device Tracker entered_home/left_home device triggers or is_home/is_not_home conditions	state trigger to: home / to: not_home, or state condition	These were removed in 2026.5 — state triggers and conditions are the correct replacements	automation-patterns #presence-and-person-triggers-and-conditions-removed-in-20265
Entity list in a trigger where an area/floor/label target fits	Purpose-specific trigger with target: {area_id: ...}	Automation follows area membership as devices change — no stale entity lists	automation-patterns #purpose-specific-triggers--conditions-default-since-20267
Old purpose-specific keys (battery.low, vacuum.docked, timer.time_remaining, ...) or trigger behavior: any/last	Renamed 2026.7 keys (battery.became_low, ...) and behavior: each/all	Old keys no longer load; old behavior values raise a repair issue and face removal	automation-patterns #purpose-specific-triggers--conditions-default-since-20267
AppDaemon: callbacks in __init__, uncancelled run_in timers, state in instance variables, hardcoded entity IDs	Register in initialize(), cancel before rescheduling, persist via input_* helpers, pass IDs through self.args	Each fails silently, resets on reload, or blocks reuse	appdaemon #appdaemon-specific-anti-patterns
Blueprints: hardcoded entities, free text where a selector belongs, !input inside a template, missing source_url	Typed !input selectors; bind an input to variables: before templating it; always set source_url	Hardcoding defeats reuse, text lets typos through, and !input is a YAML tag rather than a template value	blueprint-guide #common-pitfalls
Backups: full restore to undo one object edit, no backup before an irreversible operation (registry deletion, integration removal, Core/OS upgrade), calling an action "reversible" without naming its inverse	Roll the single object back; take the backup before; name the exact inverse or treat it as irreversible	A full restore reverts every unrelated change since and restarts HA; a backup taken afterward captures the damage	backups #when-a-full-backup-earns-its-cost
Restoring a backup, deleting a backup, or upgrading Core or the OS without explicit user confirmation	Ask, name the concrete effect, and wait for an answer — every time, backup or not	A full restore discards everything since the archive for all restored parts and restarts HA; a Supervisor partial restore overwrites only the selected archive parts; deletion destroys a recovery point; a Core/OS upgrade is high-impact and its recovery path IS the pre-upgrade backup	backups
The same non-trivial Jinja expression repeated across templates	Once a native trigger/condition and a built-in helper are ruled out, define it once as a macro in config/custom_templates/*.jinja and import it	One definition to fix when the rule changes, instead of copies that drift apart	template-guidelines #reusable-macros
trigger, this, value_json, or a {% set %} variable used inside an imported macro	Pass it to the macro as an argument	An import does not carry the caller's context — the variable is undefined inside the macro, so it renders empty and any attribute access on it errors (HA's own functions like states are globals and do work)	template-guidelines #imports-do-not-carry-the-callers-context

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Reference Files

Read these when you need detailed information:

File	When to read
safe-refactoring	Renaming entities, replacing helpers, restructuring automations, or any modification to existing config
automation-patterns	Writing triggers, conditions, waits, variables, or choosing automation modes; capturing action responses; documenting/annotating steps; disabling automations; continue_on_error, stopping a sequence, repeat, if/then vs choose, parallel, trigger IDs
helper-selection	Deciding whether to use a built-in helper vs template sensor — aggregation, rate of change, thresholds, time-in-state, counting/timing, scheduling, grouping, probabilistic inference, smoothing, climate, domain conversion, decision matrix
template-guidelines	Confirming templates ARE appropriate for a use case; sharing Jinja logic between templates with custom_templates macros
yaml-only-integrations	Creating or editing YAML-only integrations that have no config flow (e.g. command_line, platform-based mqtt, rest)
device-control	Writing actions, button/remote automations, or using target:
scenes	Authoring or activating scenes; snapshot/restore patterns; snapshot-vs-script distinction
dashboard-guide	Designing or modifying Lovelace dashboards — layout, view types, strategies, sections, cards, badges, CSS styling, HACS
dashboard-cards	Looking up available card types or fetching card-specific documentation
domain-docs	Looking up integration/domain documentation, or the dedicated doc page for a specific trigger, condition, or action
examples.yaml	Need compound examples combining multiple best practices
appdaemon	AppDaemon apps: when to use vs. native HA, app structure, actions, scheduling, error handling, safe refactoring impact
blueprint-guide	Authoring reusable blueprints: metadata & source_url, inputs & selectors, target vs entity, defaults, input sections, !input templating, versioning
backups	Deciding whether an operation needs a backup first; choosing between a full restore, a partial restore, and rolling one object back; what an archive actually contains; encryption keys and the emergency kit; restore verification; what HA does and does not protect when deleting a backup