Home Assistant Cast

What is Home Assistant Cast?

Home Assistant Cast allows you to show your Home Assistant data on a Chromecast device and allows you to interact with Home Assistant on Google Assistant devices with a screen.

What are the Home Assistant Cast requirements?

Home Assistant Cast requires a Home Assistant installation that is accessible via HTTPS (the url starts with "https://").

What is Home Assistant?

Home Assistant is worlds biggest open source home automation platform with a focus on privacy and local control. You can install Home Assistant for free.

Visit the Home Assistant website.

Why does my Home Assistant needs to be served using HTTPS?

The Chromecast only works with websites served over HTTPS. This means that the Home Assistant Cast app that runs on your Chromecast is served over HTTPS. Websites served over HTTPS are restricted on what content can be accessed on websites served over HTTP. This is called mixed active content (learn more @ MDN).

The easiest way to get your Home Assistant installation served over HTTPS is by signing up for Home Assistant Cloud by Nabu Casa.

Why does Home Assistant Cast require me to authorize my Home Assistant instance?

You're currently looking at the Home Assistant Cast launcher application. This is a standalone application to launch Home Assistant Cast on your Chromecast. Because Chromecasts do not allow us to log in to Home Assistant, we need to supply authentication to it from the launcher. This authentication is obtained when you authorize your instance. Your authentication credentials will remain in your browser and on your Cast device.

Your authentication credentials or Home Assistant url are never sent to the Cloud. You can validate this behavior in the source code.

The launcher application exists to make it possible to use Home Assistant Cast with older versions of Home Assistant.

Starting with Home Assistant 0.97, Home Assistant Cast is also built into the Lovelace UI as a special entities card row. Since the Lovelace UI already has authentication, you will be able to start casting right away.

Wat does Home Assistant Cast do?

Home Assistant Cast is a receiver application for the Chromecast. When loaded, it will make a direct connection to your Home Assistant instance.

Home Assistant Cast is able to render any of your Lovelace views on your Chromecast. Things that work in Lovelace in Home Assistant will work in Home Assistant Cast:

Render Lovelace views, including custom cards
Real-time data stream will ensure the UI always shows the latest state of your house
Navigate between views using navigate actions or weblinks
Instant updates of the casted Lovelace UI when you update your Lovelace configuration.

Things that currently do not work:

Live videostreams using the streaming integration
Specifying a view with a single card with "panel: true".

How do I change what is shown on my Chromecast?

Home Assistant Cast allows you to show your Lovelace view on your Chromecast. So to edit what is shown, you need to edit your Lovelace UI.

To edit your Lovelace UI, open Home Assistant, click on the three-dot menu in the top right and click on "Configure UI".

What browsers are supported?

Chromecast is a technology developed by Google, and is available on:

Google Chrome (all platforms except iOS)
Microsoft Edge (all platforms except iOS)

Why do some custom cards not work?

Home Assistant needs to be configured to allow Home Assistant Cast to load custom cards. Starting with Home Assistant 0.97, this is done automatically. If you are on an older version, or have manually configured CORS for the HTTP integration, add the following to your configuration.yaml file:

http:
  cors_allowed_origins:
    - https://cast.home-assistant.io

Some custom cards rely on things that are only available in the normal Home Assistant interface. This requires an update by the custom card developer.

If you're a custom card developer: the most common mistake is that LitElement is extracted from an element that is not available on the page.