Priority Command Arbitration for Home Assistant

Give every command a level of authority, so a manual action and an automation can disagree without one silently clobbering the other.

The problem

An automation turns the porch light on at dusk. You turn it off, because you are going to bed early. Twenty minutes later another automation turns it back on. Or the "restore" automation you wrote to clean up afterwards puts back a state that stopped being true an hour ago.

The usual fixes are an input_boolean guard, a scene you capture and restore, or a set of automations that all know about each other. They work until two of them disagree. If anything changes while your override is active, the state you captured is already stale by the time you restore it.

Home Assistant already records context: every service call carries who or what triggered it, so you can trace it afterwards or branch on it in a template. What it has no notion of is authority. Nothing arbitrates between two callers that both want the same entity. Every service call is a naked write, and the last one wins.

Building automation solved this a long time ago. BACnet gives every commandable point a priority array: sixteen levels, the lowest-numbered occupied level wins, and writers release their claim when they are done. This is that idea, trimmed to five levels because sixteen is more than a house needs.

What it looks like

Open any supported entity. Without any overrides, there is a level picker, a lease picker, and one row showing that ordinary traffic holds the entity:

With two overrides in place, you can see the whole array and what is queued behind what is winning:

Manual Emergency is driving, so the light is off. Each level carries its own remaining lease and can be released on its own, or all at once.

The pickers are modifiers, not buttons. Choose a level and an optional expiry, then use the entity's ordinary controls (the toggle, the brightness slider, the cover position handle) and those commands carry the level you picked. Set a light to 47% at Manual Emergency for half an hour and that is exactly what gets written.

The levels

Level	Name	Who writes here
1	Manual Emergency	You, overriding everything
2	Automatic Emergency	Life-safety automations (smoke, freeze, water leak)
3	Manual	You, when you do not want ordinary automations interfering
4	Automatic	An automation that needs to hold against ordinary traffic
5	Default	Everything else

The lowest-numbered occupied level drives the device. Writes at the same level replace each other. A command at 3 cannot be overridden by an automation writing at 4, but a smoke alarm writing at 2 still gets through.

When a level is released, control falls to the next occupied level down, and that command is re-issued as it stands right now, not as a snapshot taken when the override began.

It changes nothing until you ask it to

Everything defaults to level 5, including automations. Since same-level writes replace each other, a house that never mentions priority behaves exactly as it does today: last command wins, and you can always countermand an automation from the app (though that automation may fire again and countermand you).

If you already have input_boolean guards, you do not have to remove them to try this. Leave them in whatever state disables them and they simply stay out of the way.

That default is deliberate. Splitting it (automations at 4, people at 3) is the faithful BACnet reading, and it is wrong here. Home Assistant automations fire and forget; there is no relinquish idiom. Level 4 would fill up and never drain, and every entity an automation had ever touched would go deaf to the UI. Arbitration has to be something you opt into per command, not something that accumulates behind your back.

Two worked examples

Two automations that wanted the same light

On a time-of-use rate plan, a light turns orange during peak hours as a reminder not to start the oven. That same light is also useful for illumination, so it comes on as a white light in sync with another light nearby.

Without arbitration, those two automations have to know about each other so they do not fight, and the coupling gets worse every time a third reason to touch that light appears.

With it, the sync automation fires at Default and the alert automation fires at Automatic. Automatic outranks Default, so during peak hours the alert wins no matter what the light was doing. At the end of peak, the alert automation releases its level:

# peak starts
- action: light.turn_on
  target: {entity_id: light.kitchen}
  data:
    rgb_color: [255, 140, 0]
    priority: 4          # Automatic

# peak ends
- action: priority.relinquish
  target: {entity_id: light.kitchen}
  data: {priority: 4}

On release, control falls to whatever the sync automation currently wants, which is re-issued as it stands at that moment. Neither automation contains a single line about the other, and each still does exactly one job.

An interlock that ordinary automations cannot undo

A well pump should cut out when the energy monitor says it is sucking air, and it should stay out until a person clears it, even though another automation also commands that relay on its own schedule.

Writing the cut at Automatic Emergency does that:

- action: switch.turn_off
  target: {entity_id: switch.pump}
  data:
    priority: 2          # Automatic Emergency

The scheduling automation keeps running and keeps writing at Default. Those writes are recorded, not dispatched, because level 2 outranks them. The pump stays off until someone calls priority.relinquish on level 2, at which point the schedule takes over again with whatever it currently wants.

Note that no priority_ttl is set here. That is the right call for a safety interlock, and it is also the case worth being careful about: an indefinite hold stays until something releases it. See the caveats.

Temporary overrides

"Turn this light on for twenty minutes, then put it back" has never had a clean answer. The usual shape is turn on, delay, turn off. That breaks if anything else touches the light meanwhile, it breaks across a restart, and it hardcodes "off" as the thing to return to even when that was never true.

Give the command a level and a lease instead. Say an automation turns light.porch off at 10pm, at Default, and at 9pm you want it kept on for two hours:

action: light.turn_on
target:
  entity_id: light.porch
data:
  brightness_pct: 60
  priority: 3              # Manual
  priority_ttl: "02:00:00"

The array now holds:

3  Manual    turn_on    2h 0m left    <- driving
5  Default   turn_on

At 10pm the automation fires. The light does not turn off. Home Assistant records that something wants it off at level 5, but level 5 did not win:

3  Manual    turn_on    1h 0m left    <- driving
5  Default   turn_off

At 11pm the lease expires and level 3 clears. Default is the only occupied level left, so its command is dispatched and the light goes off:

5  Default   turn_off                 <- driving

Notice what did not happen: nothing was captured at 9pm and replayed at 11pm. The lease does not turn the light off, it stops overriding, and Default's command is dispatched as it stands at that moment. That is why an expiring override lands on Default rather than on the prior state. Had the automation wanted the light on at 11pm, it would have stayed on, because its command was outranked the whole time rather than discarded. A lease also survives a restart, which a delay does not.

Omit priority_ttl (or pass 0) to hold until something releases it. An override with no end is easy to issue and easy to forget, and until it is released everything underneath it is dead. It is rejected at level 5, which has nothing below it to expire back to.

Physical switches

Now suppose that at 10:30pm, with half an hour still left on that override, you walk over and hit the switch on the light itself.

Home Assistant sees the state change and knows it did not command it, so it attributes the change to a person and records it at Default. It does not re-send the on command. Your override stays in the array until it expires or something outranks it, but nothing is re-asserted against you while Home Assistant is running. The house should not argue with someone standing at a light switch.

Wall switches, vendor apps and Zigbee group commands are all handled this way.

Using it in YAML

Every arbitrated service takes two extra fields alongside whatever it already accepts:

action: cover.set_cover_position
target:
  entity_id: cover.garage
data:
  position: 40
  priority: 3
  priority_ttl: "03:00:00"

Both appear as real form fields in the automation editor, the script editor, Developer Tools and button tap actions, so you get a proper dropdown rather than having to remember the YAML. The integration rewrites the affected service descriptions at runtime.

Services

Four services are registered for scripts that need to write, release or inspect an array directly.

priority.set

Writes a level without going through the domain service.

action: priority.set
target:
  entity_id: light.porch
data:
  priority: 3
  service: turn_on
  data:
    brightness: 200
  priority_ttl: "00:30:00"     # optional

Field	Required	Notes
priority	yes	1 to 5
service	yes	The bare domain service (turn_on, set_temperature). The domain comes from the target entity.
data	no	The payload that service would take
priority_ttl	no	Duration. Rejected at level 5.

Both the service and the payload are validated before anything is written, and every target is validated before any slot is written. A slot that cannot dispatch would still win arbitration and sit there holding the entity with nothing driving it, which is a silent black hole.

priority.relinquish

Clears one level. If that level was in control, whatever occupies the next level down is re-driven using its current command.

action: priority.relinquish
target:
  entity_id: light.porch
data:
  priority: 1

You do not need to re-issue the level below. Releasing 1 when Manual (3) is occupied lands control on 3 by itself.

priority.relinquish_all

Clears every level above Default.

action: priority.relinquish_all
target:
  entity_id: light.porch

priority.get

Returns the full array. This is a response service.

action: priority.get
target:
  entity_id: light.porch
response_variable: priority_state

The response has a single top-level key, arrays, keyed by entity id:

arrays:
  light.porch:
    entity_id: light.porch
    effective_priority: 1
    effective_priority_name: Manual Emergency
    effective_command:
      domain: light
      service: turn_on
      data: {brightness: 200}
      written_at: "2026-08-14T04:11:07.882Z"
      written_by: <user id or automation entity id>
      expires_at: "2026-08-14T04:41:07.882Z"   # null if no lease
    slots:
      "1": {domain, service, data, written_at, written_by, expires_at}
      "2": null
      "3": null
      "4": null
      "5": {...}

Notes that will save you an hour:

• Slot keys are strings, "1" through "5", not integers.
• The effective_* fields are null only when nothing at all holds the entity, which is not the same as Default holding it. An ordinary command lands at 5 and reports as level 5. In practice null shows up after a restart, for an entity nothing has commanded yet.

So the test for "something is overriding this" is:

- condition: template
  value_template: >
    {{ priority_state.arrays['light.porch'].effective_priority not in [5, none] }}

and to branch on a specific level:

- condition: template
  value_template: >
    {{ priority_state.arrays['light.porch'].effective_priority == 1 }}

A double-click that drops an override

Releasing an emergency hold early and putting something specific underneath it is two calls in a script, no UI required:

- action: priority.relinquish
  target: {entity_id: light.kitchen}
  data: {priority: 1}

- action: priority.set
  target: {entity_id: light.kitchen}
  data:
    priority: 3
    service: turn_on
    data: {brightness: 200}

Dashboard cards

custom:priority-feature is a tile card feature, not a card. Add it to any tile card and the same pickers and array appear there:

type: tile
entity: switch.garage_loft
features:
  - type: custom:priority-feature

This uses a supported frontend extension point, unlike the more-info row, so it is the safest of the three UI surfaces. The tile on the right has nothing recorded, which is what an untouched entity looks like.

custom:priority-overrides-card lists everything currently held, with one-click release:

custom:priority-control-card issues commands at a level, for a chosen set of entities:

Taking, releasing and expiring an override are all written to the entity's logbook, so the history shows what held it and when. There is also an Active overrides sensor whose state is the number of levels currently held, with the details in its attributes.

Supported domains

light, switch, fan, cover, climate, water_heater, humidifier, lock, valve, media_player, input_boolean, input_number.

Only services that actually command a device are wrapped (light.turn_on, cover.set_cover_position, climate.set_temperature and so on). Queries and configuration services, and every other domain, pass through untouched.

Configuration

Set at install time and changeable afterwards from the integration's Configure button.

Option	Default	What it does
Scope	All entities	Arbitrate every entity in the supported domains, or only a selected set
Excluded entities	none	Never arbitrated, even under all
Managed entities / areas / labels	none	Under selected scope, what to include
Default priority for users	5	The level a command gets when a person does not name one
Default priority for automations	5	The same, for automations
Track out-of-band changes	on	Record physical switches and vendor apps at Default

Changing the two default-priority options away from 5 is the one setting that can surprise you, for the reasons in the section above about why everything defaults to 5.

Installation

HACS, Custom repositories, add https://github.com/triosniolin/ha-priority as an Integration, install, restart, then add Priority Command Arbitration from Settings, Devices & Services. Or copy custom_components/priority into your config directory and restart.

Hard-refresh your browser afterwards so the dashboard parts load. The cards register themselves, so there is no Lovelace resource step.

Home Assistant 2026.8.1 or newer. Not in the HACS default store yet; that needs a brands PR.

How it works

No fork of Home Assistant is required. For each arbitrated service the integration takes the Service object already in the registry and registers a wrapper under the same name. The wrapper holds the arbitration decision; the captured original is the only thing that ever touches a device.

Dispatch deliberately does not go back through hass.services.async_call. The captured job is invoked directly, which makes recursion structurally impossible rather than something a guard flag has to catch, and means one relinquish produces exactly one dispatch.

Changes that do not match any dispatch of ours are attributed to the physical world and recorded at Default.

Caveats

Read the first two. They are the ones that could actually cost you something.

It rewrites the service registry

For every supported service (about fifty of them) this pulls the registered handler out of the live service registry and registers a wrapper over the same name. That is the central bet, and it rests on Home Assistant internals rather than public API: async_services_internal(), the shape of Service, and the target-resolution helpers.

Those can change in any core release. The code is careful about it (a marker so a reload cannot double-wrap, a suspend flag so re-registering does not retrigger the registration listener, originals restored on unload) but careful does not help if core renames something. The realistic bad day is an upgrade after which supported entities stop responding, fixed by removing the config entry.

Two things reduce that risk rather than just describing it. tests/test_core_contract.py asserts every core internal this depends on, so a break is one obvious failure naming exactly what moved instead of eighty confusing ones. CI runs that suite weekly against current Home Assistant, so a core release that breaks it shows up as a red build rather than as your lights going unresponsive.

A suppressed command reports success

If a level is holding an entity and something lower tries to move it, the command is recorded and not dispatched. The service call still returns successfully. There is no error to the caller, so a script, a voice assistant or a dashboard button will all look like they worked.

For a light that is mildly confusing. For lock and valve it is worth thinking about first: a forgotten indefinite override on a lock is a genuinely bad failure mode. Either use priority_ttl so overrides expire on their own, or exclude those entities in the options flow. The Active overrides sensor and the overrides card exist to make a forgotten hold visible, but they only help if you look.

Everything else

• It is new. It is in daily production use and has a test suite behind it, but the user base is small. Treat it accordingly.
• The more-info row patches a compiled frontend element, because there is no supported way for a custom integration to add controls to a built-in card. It is written to fail closed: if a Home Assistant update breaks it, the row stops appearing and nothing else changes. The tile card feature uses a supported extension point and is the fallback.
• Every override level (1 to 4) is restored across a restart, leases included. A lease that lapsed while Home Assistant was down is dropped rather than resurrected. Level 5 is not restored, since it is ordinary last-wins traffic and a stored copy of it would be a claim about physical reality that may have moved while Home Assistant was down.
• A restored hold at level 1 or 2 is re-issued once, about half a minute after startup finishes. Nothing else is. While Home Assistant is running the array is never re-asserted against reality, but a restart is the one case that rule does not cover honestly: a change during downtime was observed by nobody, so a power blip that dropped a relay looks identical to a person deciding something. At the emergency levels that is worth one command; at 3 and 4 it is not, and silently re-commanding devices on every boot would be too surprising to do on your behalf. Entities still unavailable at that point are skipped and picked up when they return.
• entity_id: all is arbitrated. A goodnight scene or an "all off" sweep will not defeat your overrides: held entities are skipped, everything else is switched normally. This was not true before 2026-08-11, when all bypassed arbitration entirely.

Development

python -m venv .venv && .venv/bin/pip install -r requirements-test.txt
.venv/bin/python -m pytest tests/     # integration behaviour
node tests/card_test.js               # frontend logic

Licence

Apache 2.0, matching Home Assistant core so the code can be proposed upstream without a relicensing step.