Counter decremented

The Counter decremented trigger fires when a counter helperA helper is a virtual entity you create inside Home Assistant. It is not backed by a physical device. Helpers store values, track state, or do calculations that your automations and dashboards need. [Learn more] decreases by its configured step size. Use it when you want an automation to react as a count goes down, like turning something off, sending a warning that a balance is getting low, or reacting when a user-created tally is being worked back down to zero.

Using this trigger from the user interface

If you prefer building automations visually, Home Assistant walks you through this trigger step by step. You pick what to watch, tweak a few options, and save. No YAML knowledge required.

To use this trigger in an automation:

1. Go to Settings > Automations & scenes.
2. Open an existing automation, or select Create automation > Create new automation.
3. In the When section, select Add trigger.
4. Select what you want to monitor. Under By target (see Targets), pick the counter helper you want to monitor. You can also select an area, a floor, a device, or a label.
5. From the triggers shown for that target, select Counter decremented.
6. Select Save.

Options in the UI

This trigger has no additional options in the UI.

Using this trigger in YAML

If you work directly in YAML, or you want to know exactly what Home Assistant does under the hood, this section has the technical reference. It lists the field names you use in YAML, their types, and which ones are required.

In YAML, refer to this trigger as counter.decremented. A basic example looks like this:

trigger: counter.decremented
target:
  entity_id: counter.items_left

This fires when counter.items_left decrements.

Options in YAML

This trigger has no additional YAML options.

Targets of the trigger

This trigger requires a target. The target is the object that Home Assistant will watch. You can select a single entityAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more], a device, an area, a floor, or a label as a target, and Home Assistant will watch every matching counter entity behind that target.

• Entity: one specific counter entity, such as counter.living_room.
• Device: every counter entity that belongs to a device.
• Area: every counter entity in a room or area.
• Floor: every counter entity on a floor.
• Label: every counter entity that shares a label.

You can also select different target types in one trigger. For example, you can add a specific entity and an area as targets in the same trigger to monitor both of them at once.

Good to know

• The trigger fires each time the counter decrements.
• A counter in the unknown or unavailable state does not fire the trigger until it has a valid value again.
• Resetting a counter does not count as a decrement. To react to resets, use Counter reset.
• To react only when a counter reaches its configured minimum, use Counter reached minimum.

Try it yourself

Ready to test this? Go to Settings > Automations & scenes, create a new automation, and add this trigger. Save the automation, then change the state of the targeted entity to watch the trigger fire on your actual entitiesAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more].

More examples

Real scenarios where this trigger fires in automations and scripts. Copy any example and adapt it to your setup.

Automation: turn off a fan when a break counter decrements to its last step

If you have created a counter helper to track short cooling breaks, you can turn off a fan whenever the count is worked back down.

• Trigger: Counter decremented
  • Target: Cooling break counter
• Action: Turn off fan

alias: "Turn off the fan when the cooling break counter decrements"
triggers:
  - trigger: counter.decremented
    target:
      entity_id: counter.cooling_breaks_left
actions:
  - action: fan.turn_off
    target:
      entity_id: fan.office

Automation: send a message when a queue counter decrements

If you use a counter helper to track chores left to finish, you can send a quick update each time the count goes down.

• Trigger: Counter decremented
  • Target: Chore queue counter
• Action: Send a notification message
  • Target: My Device (notify.my_device)

alias: "Notify when the chore queue counter decrements"
triggers:
  - trigger: counter.decremented
    target:
      entity_id: counter.chores_left
actions:
  - action: notify.send_message
    target:
      entity_id: notify.my_device
    data:
      message: "The chore queue counter went down."

Still stuck?

The Home Assistant community is quick to help: join Discord for real-time chat, post on the community forum with the trigger you’re using and what you expected to happen, or share on our subreddit /r/homeassistant.

Related triggers

These triggers work well alongside this one:

• Counter incremented: Triggers after one or more counters increment.

• Counter reached minimum: Triggers after one or more counters reach their minimum value.