How to integrate Google Calendar with Home Assistant

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Our in-depth guide unlocks the full potential of integrating Google Calendar with Home Assistant, transforming your day-to-day automations and scripts. Imagine your entire schedule seamlessly blended into your smart home ecosystem, displayed elegantly on the Home Assistant Dashboard through the stunning Calendar Card. While basic guides may leave you wanting more, our comprehensive walkthrough, enriched with detailed screenshots and expert tips, is tailored to ensure a smooth and efficient integration experience, elevating your smart home to new heights of convenience and functionality.


Setting Up on Google Cloud Platform

Integrating Google Calendar with Home Assistant requires more than a simple URL copy-paste or dashboard clicks. The process begins on the Google Cloud Platform, which may seem daunting at first. But fear not! By following these steps, you can easily set up your integration.

Creating a Google Cloud Platform Project

Begin by creating a new project or selecting an existing one on the Google Cloud Platform. For a thorough guide, I'll demonstrate creating a new project. However, if you have a pre-existing project from a previous integration, it's best to use that to avoid multiple individual projects.

Home Assistant Google Calendar 16
Home Assistant Google Calendar 14

After project creation or selection, a confirmation message will appear, signalling the API's activation. Click on 'go to credential' to proceed. Keep the API set to Google Calendar API. Since this integration doesn't collect third-party user data, selecting 'application data' is appropriate. Answer 'no' to the final question, as this integration does not require access to other services.

In the 'service account details' section, assign a name to your account and take note of the assigned account identification. You can also add a description if desired. The next two parts are optional and can be quickly completed by clicking 'done'.

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Home Assistant Google Calendar 11

Generating Client ID and Secret for Home Assistant

The next step involves configuring a consent screen in the Google Cloud Console. Choose the external user type and create your “app” (a term used in the process) by naming it, preferably Home Assistant, and providing your email as the user support email. Fill in the required information and proceed.

Skip the scopes section and add your email as a test user. This completes the consent screen configuration.

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Home Assistant Google Calendar 02
Home Assistant Google Calendar 07

Creating Home Assistant Credentials in the Google Cloud Platform

Now, create credentials for Home Assistant to access Google Calendar. In the APIs and services page, select 'create credentials' and choose 'OAuth client ID'.

Select 'TVs and Limited Input devices' as the application type and name it recognizably, like 'Home Assistant Credentials'. After creation, a pop-up with your client ID and secret will appear. Copy these to an external editor for later use, and remember never to share them. If you were to accidentally leak your credentials, delete them immediately and create a new set.

If accidentally closed, you can retrieve them from the credentials overview. Simply click on the pencil icon, and they will be displayed on the right-hand side.

Home Assistant Google Calendar 01
Home Assistant Google Calendar 15
Home Assistant Google Calendar 12

Enabling the Google Calendar API

To prevent future issues, verify that the Google Calendar API is enabled by clicking on 'Library' in the menu and searching for the Google Calendar API. It should be enabled, as signified by a green tick; if not, enable it here.

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Home Assistant Google Calendar 09

Completing Google Calendar Integration with Home Assistant

Now, almost there with integrating Google Calendar into Home Assistant! Add the copied client ID and secret to your configuration.yaml file:

  client_id: YOUR_CLIENT_ID
  client_secret: YOUR_CLIENT_SECRET
  # Optional options

For security, store these credentials in your secrets.yaml file instead of directly in the configuration file. Additional configuration options include:

As the client identification and secret strings are highly confidential, I recommend storing them in your secrets.yaml file, and not directly in the configuration file. There are two further optional options that can be configured:

Restart Home Assistant and wait for the authentication notification, but note there might be a current issue preventing its appearance, which shall be tackled in the following paragraphs.

Resolving Authentication Issues

If an error stating “Authentication code expired, please restart Home Assistant and try again” appears, set your time zone to Etc/GMT in general settings, restart Home Assistant, and then complete the authentication. Afterward, revert to your original time zone.

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Home Assistant Google Calendar 03

Configuring Individual Calendars

Your Google Calendars will now be visible in Home Assistant’s developer options, and a google_calendars.yaml file will be created. Customize this file as needed, ensuring not to alter the cal_id.

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Required variables for the Google Calendar integration with Home Assistant

Optional variables for the Google Calendar integration with Home Assistant

A portrait photo oif Liam Alexander Colman, the author, creator, and owner of Home Assistant Guide wearing a suit.

About Liam Alexander Colman

is an experienced Home Assistant user who has been utilizing the platform for a variety of projects over an extended period. His journey began with a Raspberry Pi, which quickly grew to three Raspberry Pis and eventually a full-fledged server. Liam's current operating system of choice is Unraid, with Home Assistant comfortably running in a Docker container.
With a deep understanding of the intricacies of Home Assistant, Liam has an impressive setup, consisting of various Zigbee devices, and seamless integrations with existing products such as his Android TV box. For those interested in learning more about Liam's experience with Home Assistant, he shares his insights on how he first started using the platform and his subsequent journey.

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