Home Assistant Blueprint: Offline detection for Z2M devices with last_seen

offline-notification-for-sensors-with-last_seen.yaml

blueprint:
  name: Offline detection for Z2M devices with last_seen
  description: Regularly test all sensors with 'last_seen' in name and 'timestamp' device_class
    ('last seen' Z2M sensors) to detect offline and if so execute an action.
  domain: automation
  input:
    hours:
      name: Hours not seen
      description: Sensors not seen this amount of time are assumed to be offline.
      default: 24
      selector:
        number:
          min: 1.0
          max: 168.0
          unit_of_measurement: h
          mode: slider
          step: 1.0
    time:
      name: Time to test on
      description: Test is run at configured time
      default: '10:00:00'
      selector:
        time: {}
    day:
      name: Weekday to test on
      description: 'Test is run at configured time either everyday (0) or on a given
        weekday (1: Monday ... 7: Sunday)'
      default: 0
      selector:
        number:
          min: 0.0
          max: 7.0
          mode: slider
          step: 1.0
    exclude:
      name: Excluded Sensors
      description: "'last seen' sensors (from devices that you want to exclude) to
        exclude from detection. Only entities with 'last seen' in name and 'timestamp'
        in device_class are supported, devices must be expanded!"
      default:
        entity_id: []
      selector:
        target:
          entity:
            domain: sensor
    actions:
      name: Actions
      description: Notifications or similar to be run. {{sensors}} is replaced with
        the names of sensors being offline.
      selector:
        action: {}
  source_url: https://gist.github.com/Mr-Groch/bf073b142b507e3b6f8154223f81803b
variables:
  day: !input 'day'
  hours: !input 'hours'
  exclude: !input 'exclude'
  sensors: "{% set result = namespace(sensors=[]) %}\
    \ {% for state in states.sensor | rejectattr('attributes.device_class', 'undefined') | selectattr('attributes.device_class', '==', 'timestamp') %}\
    \   {% if 'last_seen' in state.entity_id and not state.entity_id in exclude.entity_id and (states(state.entity_id) == 'unavailable' or ((as_timestamp(now()) - as_timestamp(states(state.entity_id))) > ((hours | int) * 60 * 60))) %}\
    \     {% set result.sensors = result.sensors + [state.name | regex_replace(find=' last seen', replace='') ~ ' (' ~ relative_time(strptime(states(state.entity_id), '%Y-%m-%dT%H:%M:%S%z', 'unavailable')) ~ ')'] %}\
    \   {% endif %}\
    \ {% endfor %}\
    \ {{ result.sensors | join(', ') }}"
trigger:
- platform: time
  at: !input 'time'
condition:
- '{{ sensors != '''' and (day | int == 0 or day | int == now().isoweekday()) }}'
action:
- choose: []
  default: !input 'actions'
mode: single

Hello @Mr-Groch and thank you for this Blueprint that I have been using for months.

Is it possible to have a line break in the notification for each device?
This would be much more readable when there are a lot of devices offline.

thanks again

I have HA supervised + Z2M, but I don't see last_seen in the attributes. My sensors in HA have these attributes only (examlpe):
state_class: measurement unit_of_measurement: °C device_class: temperature friendly_name: Датчик на улице Температура
But in the Z2M, I see an attribute last_seen, so for the sensor from the example, I see this:
{ "humidity": 86, "last_seen": "2024-02-22T12:38:26+03:00", "linkquality": 29, "temperature": -0.2 }
How do I transfer the last_seen attribute from Z2M to HA to use this blueprint? It's not working right now.

Sorry, I figured it out myself. I've added objects that are deactivated by default. Now I see it in HA. Thanks.