Google Calendars

The google calendar platform allows you to connect to your Google Calendars and generate binary sensors. The sensors created can trigger based on any event on the calendar or only for matching events. When you first setup this integration it will generate a new configuration file google_calendars.yaml in your configuration directory that will contain information about all of the calendars you can see. It also exposes a service to add an event to one of your Google Calendars.


Generate a Client ID and Client Secret on Google Developers Console.

  1. First go to the Google Developers Console
  2. The wizard will ask you to choose a project to manage your application. Select a project and click continue.
  3. Verify that your calendar API was enabled and click ‘Go to credentials’
  4. When it gets to the Page titled Add credentials to your project just click cancel.
  5. Navigate to APIs & Services (left sidebar) > Credentials
  6. Click on the field on the right of the screen, ‘CONFIGURE CONSENT SCREEN’, select “External” and create.
  7. Set the ‘Application Name’ (the name of the application asking for consent) to anything you want. We suggest “Home-Assistant”.
  8. You then need to select a Support email. To do this, simply click the drop down box and select your email address.
  9. You finally need to complete the section: Developer contact information. To do this, simply enter your email address (same as above is fine).
  10. Scroll to the bottom and click save. (You don’t have to fill out anything else)
  11. You will then be automatically taken to the OAuth consent screen, you do not need to add any scopes here so click SAVE AND CONTINUE to move to the Test users page. You will need to add the Gmail address you will be using with this integration as a test user before you will be allowed to use the API. Once you have added your email address under Test users click SAVE AND CONTINUE which will take to the ‘Summary’ page (you do not need to do anything here).
  12. Click Credentials in the menu on the left hand side of the screen, then click + Create credentials (at the top of the screen), then select OAuth client ID.
  13. Set the Application type to TV and Limited Input and give this credential set a name (like “Home Assistant Credentials”) then click ‘Create’.
  14. You will then be presented with a pop-up saying ‘OAuth client created’ showing Your Client ID and Your Client Secret. Make a note of these (for example, copy and paste them into a text editor) as you will need to put these in your configuration.yaml file shortly. Once you have noted these strings, click OK. If you need to find these credentials again at any point then simply navigate to APIs & Services > Credentials and you will see Home Assistant Credentials (or whatever you named them in the previous step) under OAuth 2.0 Clident IDs. To view both the Client ID and Client secret, click on the pencil icon, this will take you to the settings page for these credentials and the information will be on the right hand side of the page.
  15. We need to double check that the “Google Calendar API” has been automatically enabled. To do this, select Library from the menu, then search for “Google Calendar API”. If it is enabled you will see API Enabled with a green tick next to it. If it is not enabled, then enable it.

If you will later be adding more scopes than just the “Google Calendar API” to the OAuth for this application, you will need to delete your token file under your Home Assistant Profile. You will lose your refresh token due to the re-authenticating to add more API access. It’s recommended to use different authorizations for different pieces of Google.


If you are trying to switch to a new Google account then you would run into the following error message. Make sure to delete the existing .google.token file from your config folder and restart Home Assistant to try again.

‘oauth2client.client.HttpAccessTokenRefreshError: deleted_client: The OAuth client was deleted’


To integrate Google Calendar in Home Assistant, add the following section to your configuration.yaml file:

# Example configuration.yaml entry
  client_id: YOUR_CLIENT_ID
  client_secret: YOUR_CLIENT_SECRET

Configuration Variables

client_id string Required

Use the client ID you generated in the Prerequisites stage.

client_secret string Required

Use the client secret you generated in the Prerequisites stage.

track_new_calendar boolean (Optional, default: true)

Will automatically generate a binary sensor when a new calendar is detected. The system scans for new calendars only on startup.

calendar_access string (Optional, default: read_write)

Determines the level of access that Home Assistant will request when connecting to calendars. This can be read_only or read_write.

The next time you run or restart Home Assistant, you should find a new notification (the little bell icon in the lower-left corner). Click on that notification it will give you a link and an authentication code. Click on that link to open a Google website where you should enter the code found in the notification (NOTE: You may get a message telling you that the API has not been verified and you will need to acknowledge that in order to proceed). This will grant your Home Assistant service read-only or read-write access (based on configuration) to all the Google Calendars that the account you authenticate with can read.

Calendar Configuration

With every restart all calendars of the configured Google account will get pulled and added to the google_calendars.yaml and preconfigured as a single entity. By setting the ‘track’ variable to true the calendar will get monitored for new events which can be used for automations and its content is shown on the ‘Calendar’ dashboard.

A basic entry for a single calendar looks like:

- cal_id: "*****"
  - device_id: test_everything
    name: Give me everything
    track: true

From this, we will get a binary sensor calendar.test_everything triggered by any event on the calendar and will show the next 10 events on the ‘Calendar’ dashboard.

A bit more elaborate configuration:

- cal_id: "*****"
  - device_id: test_unimportant
    name: UnImportant Stuff
    track: true
    search: "#UnImportant"
  - device_id: test_important
    name: Important Stuff
    track: true
    search: "#Important"
    offset: "!!"

From this we will end up with the binary sensors calendar.test_unimportant and calendar.test_important which will toggle themselves on/off based on events on the same calendar that match the search value set for each. calendar.test_unimportant will toggle for events whose title contain ‘#UnImportant’ calendar.test_important will toggle for events whose title contain ‘#Important’. By using the offset variable an event title containing “#Important !!-10” will toggle the sensor 10 minutes before the event starts.

If you use a # sign for search then wrap the whole search term in quotes. Otherwise everything following the hash sign would be considered a YAML comment.

Configuration Variables

cal_id string Required

The Google generated unique id for this calendar.



entities list Required

Yes, you can have multiple sensors for a calendar!

device_id string Required

The name that all your automations/scripts will use to reference this device.

name string Required

What is the name of your sensor that you’ll see in the frontend.

track boolean Required, default: true

Should we create a sensor true or ignore it false?

search string (Optional)

If set will only trigger for matched events.

offset string (Optional, default: !!)

A set of characters that precede a number in the event title for designating a pre-trigger state change on the sensor. This should be in the format of HH:MM or MM.

ignore_availability boolean (Optional, default: true)

Should we respect free/busy flags?

Sensor attributes

  • offset_reached: If set in the event title and parsed out will be on/off once the offset in the title in minutes is reached. So the title Very important meeting #Important !!-10 would trigger this attribute to be on 10 minutes before the event starts.
  • all_day: true/false if this is an all day event. Will be false if there is no event found.
  • message: The event title with the search and offset values extracted. So in the above example for offset_reached the message would be set to Very important meeting
  • description: The event description.
  • location: The event Location.
  • start_time: Start time of event.
  • end_time: End time of event.

Service google.add_event

You can use the service google.add_event to create a new calendar event in a calendar. Calendar id’s can be found in the file google_calendars.yaml. All dates and times are in your local time, the integration gets your time zone from your configuration.yaml file.

This will only be available if you have given Home Assistant read-write access (see calendar_access).

Service data attribute Optional Description Example
calendar_id no The id of the calendar you want. *****
summary no Acts as the title of the event. Bowling
description yes The description of the event. Birthday bowling
start_date_time yes The date and time the event should start. 2019-03-10 20:00:00
end_date_time yes The date and time the event should end. 2019-03-10 23:00:00
start_date yes The date the whole day event should start. 2019-03-10
end_date yes The date the whole day event should end. 2019-03-11
in yes Days or weeks that you want to create the event in. “days”: 2

You either use start_date_time and end_date_time, or start_date and end_date, or in.

Using calendar in automations

A calendar can be used as an external scheduler for special events or reoccurring events instead of hardcoding them in automations.

Trigger as soon as an event starts:

      platform: state
      entity_id: calendar.calendar_name
      to: "on"

By using specific text in the event title, you can set conditions to initiate particular automation flows on designated events while other events will be ignored.

For example, the actions following this condition will only be executed for events named ‘vacation’:

      - condition: state
        entity_id: calendar.calendar_name
        state: vacation
        attribute: message