Google has an automation scripting engine in public preview located at (https://home.google.com/) that could be of use to you to achieve what you want. To use the scripting engine, select the automation control on the left side of the page listed above.
The starter type you would be looking for would be (device.event.FaceFamiliarDetection)
The action type you would be looking for would be (home.command.Notification)
I've not tried this out myself but it's where I would start and your script would look something like this
metadata:
name: Untitled # Choose a short name that summarizes important starters and actions, like “Sunset lights”.
description: Scripted automation # Write a detailed description that includes everything the automation does, like “At sunset, on weekdays, close blinds, turn on lights to 50%, and play the sunset playlist on certain speakers.”
automations:
# “starters” and “actions” are required; “conditions” are optional.
# Use Ctrl + Space to see autocomplete suggestions.
# ---- STARTERS ---- #
# Starters describe events that will start the automation.
# To add more than one starter, duplicate the "- type" section under "starters".
# If you add multiple starter events, any one of them happening will start the automation.
starters:
- type: device.event.FaceFamiliarDetection # A familiar face has been detected by the camera.
device: Front Door Camera - Entryway
# ---- CONDITIONS ---- #
# Conditions are optional. Delete this section if it’s empty.
# Conditions will prevent an automation from starting if the conditions aren’t met.
# See g.co/home/script-editor-docs for documentation about how to use logical operators like “and”, “or”, and “not”.
condition:
type:
# ---- ACTIONS ---- #
# Actions will start when a starter event takes place and all conditions are met.
# Actions will start in the order they appear in the script and with any delay specified.
# To add more than one action, duplicate the "- type" section under "actions".
actions:
- type: home.command.Notification # Send a notification to the specified home members.
# Title of the notification. [Available parameter options: title, body, members]
title: Person Detected
body: Familiar face detected at front door
members: #
