Home Assistant Beginner’s Guide: Integrating Google Assistant

Update: Dec 31, 2022

Update: Google Home is now Nest Audio

Since my fingers first hit the keyboard for this piece, the Google Home line-up has given way to the Google Nest range. Currently, we're talking about the Nest Audio and Nest Mini. However, both are still powered by the same trusty Google Assistant found on the original Google Home devices. I've tweaked this beginner's guide to reflect these updates.

But let's be clear, this integration isn't just about turning your smart speaker into a Home Assistant sidekick. Google Assistant is sprouting up everywhere, expanding its footprint by the day. From your trusty smartphone, to wristwatches, security cams, and even car dashboards, Google Assistant is popping up like mushrooms after a rainstorm. It just so happens that Google Home was the pioneer that first introduced Google Assistant to our humble abodes.

Welcome back, home automation aficionados! As we march into the third instalment of our Home Assistant Beginner's Guide, we're delving into the task of syncing your Home Assistant with Google Assistant (which implies your Google Home, Google Nest Audio, or Google Nest Mini). By the sunset of this guide, you'll be bossing your Google Assistant around, asking it to flick the lights on in your desired hue, and handling most gizmos that you've roped into your Home Assistant.

Integration without a Nabu Casa subscription

This guide will walk you through integrating Home Assistant with Google Assistant, sans the assistance of Nabu Casa. Sure, throwing down a few bucks to use this service would streamline the process, but since I'm already lord of the domain and juggling several services alongside Home Assistant on my server, I opted for the hands-on route. That said, if you choose to shell out for Nabu Casa's monthly subscription, you'll be pitching in towards the future development of Home Assistant, which is a noble cause and one I'm not trying to dissuade you from.

Heads up, though, before you embark on this Home Assistant Beginner's Guide journey: This part might be the gnarliest yet. It involves a good dose of “coding”, and we’ll be juggling more than one tool. But fear not, I'll break it down Barney-style. We're all beginners here, after all!

Splitting hairs: Google Home, Google Nest, and Google Assistant

Before we dive head first into the actual Home Assistant Beginner's Guide, let's iron out some confusion: When I say Nest Audio, or Nest Mini, I'm talking about the hardware—the physical speaker that graces your living room. Google Assistant (GA), on the other hand, is the brains behind the operation, the software that powers the hardware. The two terms are often used interchangeably, even by Google, leading to some crossed wires. Finally, we have Google Home, which is Google's home automation service, with accompanying apps for your smartphone, smartwatch, smart speakers, and smart display.

What you need to get started

To get your Google Assistant and Home Assistant working together, you'll need a couple of things:

First off, you're going to need a smartphone that can handle the Google Home app. This could be either an iOS or Android device. Even though you don't need a Google Home, Google Nest or Nest Mini device to make the integration work, having one of these gadgets around does make the whole process a bit smoother.
Secondly, your Home Assistant needs to be accessible online. If you're not sure how to do this, you can find a step-by-step guide in the Home Assistant Beginner's Guide Part 2.
Next up, it's a good idea to use an advanced text editor like Visual Studio Code when editing files. This will make your life a lot easier and your coding experience a lot more enjoyable.
Lastly, this guide is primarily directed towards Windows users, as I'm unable to test the steps on any Apple devices.

Once you've downloaded the correct version for your operating system (most likely x86_64), copy the file into a new, empty folder. In that same folder, create a text file and rename it 'project.json' (be sure to enable 'file name extensions' in Windows Explorer, or you'll end up with a file named 'project.json.txt').

Open the file with Visual Studio Code, and populate it with the following code, replacing the URL with the one you set up with Duck DNS:

Copy the code ('$ gactions update…') and paste it into an empty notepad – we'll need that later. In the notepad, replace 'PACKAGE_NAME' with project.json and replace the '$' with './' if you're using Windows. Here's what your code should look like on a Windows machine:

Open the folder we created for the gactions CLI in the Windows Explorer. While holding down shift, right-click anywhere inside the folder. You should see an option titled 'Open PowerShell window here' – click on that.
Copy and paste the code from your notepad and paste it into the PowerShell window using 'CRTL+V'. Press 'Enter/Return' on your keyboard to run the code.
After running the code, you'll be prompted to visit a URL. Copy and paste that URL into a browser and allow 'Assistant CLI' to view and manage your Actions on Google. You'll be given a long string of code in return – copy it and paste it into the PowerShell window. Soon, you'll get a message with a URL – copy that URL.

Open the copied URL in a browser and fill in the required 'App information'. Once Google is satisfied with the details you've provided, click save. Next, click on 'back', select 'Account linking', and click on 'Edit'. Fill in the necessary information, and when prompted, select the implicit grant type. For the 'Client ID', you're going to need a long, random, and secure string. You could use something like the Random Password Generator for this – just make sure to select the maximum length.

Save this string in a notepad, we'll need it later. The 'Authorization URL' should be your Home Assistant URL, plus '/api/google_assistant/auth':

Add two scopes: 'name' and 'email'. Thereafter, add some random gibberish in the testing instructions and click save.
Finally, with all the information entered, click on 'TEST DRAFT'.
Once you've done that, click on the settings cog in the top-left corner and open the 'Project settings'. Here you'll find your 'Project ID'. Copy it into your notepad.

Giving your Home Assistant the HomeGraph API power-up

While this isn't a must-do, it's a step that's sure to make your life easier, and who doesn't want that? With the help of the HomeGraph API, your Google Assistant will be able to keep up with the latest updates on your tech terrain. Just tell it to “sync my devices”, and it'll align your Home Assistant devices with itself every time you bring a new gadget to the team or tweak an existing one. So, let's get to it. Here's how you can activate this helpful feature:

First things first, head over to the Google Cloud Platform.
Pick your project from the list and hit the ENABLE button.
Once that's done, click MANAGE. In the menu on the left, you'll find Credentials. Click on that and then on Create credentials. From the drop-down menu, select API key.
Voilà! You now have a new API key on the list. Grab it and copy it to your notepad.

Tuning up your Home Assistant

Keep your notepad at arm's reach and pull up the configuration.yaml. Here's where you'll need to conjure up another unique string for your access_token. Tweak the following code with your info, and then give your Home Assistant a quick restart from the Web UI. Be patient until it's fully booted:

Welcoming Home Assistant to the Google Home app

Now, grab your smartphone and fire up the Google Home app. Make your way to Home control (it's hiding in the menu). Tap the big + button to add new devices (in this case, our friend, the Home Assistant). The project you've just created will be sitting at the top of the list, sporting a [test] badge. Add the device and watch as all your devices set up in Home Assistant make their grand entrance!