Host reboot required

The Host reboot required trigger fires when the system Home Assistant runs on needs a reboot, for example after an update of Home Assistant OS. This is only available on Home Assistant OS.

Use it to know about it without opening Home Assistant, for example to send a notification to your phone, so you can reboot at a moment that suits you.

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. From the search box, search for and select Host reboot required.
5. Select Save.

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. For how an automation is built in YAML, refer to Automations in YAML.

In YAML, put the settings that are specific to this trigger under options. Keep target, if the trigger uses one, and general settings such as id, alias, enabled, and variables at the top level, next to trigger.

When this trigger starts an automation, it passes data about what happened to the automation. You can use this trigger data in the templates of your conditions and actions. To see which data is available, refer to Trigger data in templates.

In YAML, refer to this trigger as homeassistant.host_reboot_required. It has no options:

trigger: homeassistant.host_reboot_required

Good to know

• This trigger only fires on Home Assistant OS. On other installation types, Home Assistant does not manage the host, so it never needs a reboot.
• The reboot stays pending until the host reboots, also when you restart Home Assistant in the meantime.
• If a reboot was already pending when the automation was turned on, the trigger does not fire for it. To check for a pending reboot, use the Host reboot required condition.
• A reboot restarts Home Assistant as well, so a pending reboot also takes care of a pending restart.

Try it yourself

Ready to test this? Go to Settings > Automations & scenes, create a new automation, and add this trigger. Save the automation, and then make the trigger react. For example, change the state of the targeted 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], turn on a light that the trigger monitors, or change its brightness. To check whether the automation ran, open its traces.

For this trigger, there is no target entity to change. To test it, wait for the next update that needs a reboot, or temporarily switch to a trigger you can control while you build the rest of the automation.

More examples

Real scenarios where this trigger fires in automations and scripts. Copy any example and adapt it to your setup. In the visual editor, select the UI options listed in the example when they are available, or paste the YAML code.

Automation: notify when a reboot is needed

When the host needs a reboot, send a notification.

• Trigger: Host reboot required
• Action: Send a notification message
  • Target: My Device (notify.my_device)

alias: "Notify when a reboot is needed"
triggers:
  - trigger: homeassistant.host_reboot_required
actions:
  - action: notify.send_message
    target:
      entity_id: notify.my_device
    data:
      message: "The Home Assistant host needs a reboot."

Still stuck?

To find out why the trigger didn’t react, make the change that it should react to, and then open the traces of the automation. If the automation didn’t run, there’s usually no trace, but some triggers record a Did not trigger trace. For details, refer to Testing automations. For common problems and their solutions, refer to Troubleshooting automations.

If that doesn’t help, 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

Explore related triggers:

• Restart required: Triggers when Home Assistant needs a restart to apply installed updates or changed settings.