A tale of sadness.
I titled this post “Google Assistant not working”, but I do not think this is the usual story people expect when they see that subject.
Until about twelve months ago, we had been happily using the Google Assistant integration with Homey for many years - five or more - without issue. Voice control worked reliably: turning devices on and off, adjusting the air-conditioning temperature, and generally being part of daily life in our home.
Then, about a year ago, I made what turned out to be a very unfortunate decision.
Some devices were not syncing correctly in the Google Home app, so I disconnected Homey from Google Home, assuming I could simply reconnect it afterwards. At the time, I did not realise this was likely a Google or Homey issue rather than a configuration problem.
That moment was the last time Google Assistant ever worked with Homey in our house.
When I tried to reconnect Homey through the Google Home app, I was met with the same message every time:
“Could not reach Homey. Please try again.”
At first, I assumed it was temporary. I tried reconnecting daily for a few weeks, while my family increasingly complained that they “couldn’t talk to Google anymore.” A few weeks became a month, then another month, with no change.
In March, I finally logged a support ticket with Homey (ticket #132783). We went through all the usual troubleshooting steps: backing up and restoring Homey, connecting it directly to a mobile phone, and even adding the Homey support team as an admin so they could attempt to link it to their own Google account. Nothing worked. The final update on that ticket was:
“Our developers are trying to find a solution for this.”
Months passed.
I searched the Homey forums for others with the same problem—nothing. No similar reports, no workarounds, just silence.
I then tried collecting ADB logs from the device (relevant later, as I am using Android). ChatGPT suggested the logs showed the Google Home app’s WebView crashing, but there was nothing conclusive or actionable.
In April, I tried contacting Google support. I managed to get through to someone via chat, but was ultimately brushed off with advice I can no longer even recall—it led nowhere.
Over the following months, I periodically tried reconnecting Homey, always with the same error. By this point, I had submitted well over 100 feedback reports through the Google Home app. There was never any response.
In October, I contacted Google support again. Once more, I reached someone via chat. We worked through an extensive list of troubleshooting steps, and for almost every one I had to respond with, “I’ve already tried that”:
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Clearing Google Home app data and cache
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Using a different phone
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Ensuring both devices were on the same 2.4 GHz network
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Trying mobile data instead of Wi-Fi
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Relinking Homey
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Verifying app permissions
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Confirming the Homey app itself worked correctly
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Testing with a different Google Home
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Testing with a different Google account
Eventually, they said they were interested in investigating further and would follow up via email. For the first time in a long while, I thought we might actually be getting somewhere.
They did follow up.
Unfortunately, the email simply asked the same questions all over again.
When I asked how we could actually troubleshoot the underlying problem, the conversation stopped. No next steps. No guidance. Nothing.
In one of my moments of troubleshooting and despair, I find a way to remote debug the webview on my Android device and find the a problem.
The callback to the Google Home App is not working, I excitedly send an email back to Google support
Here’s the specific failure I’m seeing:
After authenticating with Homey/Athom successfully, the OAuth handoff back to Google fails. Homey returns a valid auth code to:
https://oauth-redirect.googleusercontent.com/r/athom-cloud-assistant-devices?...
Google then redirects to:
https://oauth-redirect.googleusercontent.com/a/com.google.android.apps.chromecast.app?...&service=athom-cloud-assistant-devices
This final step returns HTTP 404.
So the issue appears to be Google’s redirect handler for athom-cloud-assistant-devices not being registered or mapped correctly. Homey’s OAuth endpoint is responding normally - the failure occurs only once Google takes over the redirect.
Let me know if you need the HAR file; happy to provide it.
Google support didn’t appear to have seen my email, as they asked if my iPhone or iPad is on the same local network (I did mention that I was using Android many times), and the firmware version of the Google Home App, if my VPN is turned off and if Bluetooth is on.
Next and last response on the 19th of November is how to troubleshoot a hardware fault on a Google speaker and provide feedback to them.
I sent them another email:
*Hi,
I’ve dug further into this issue while waiting for an update, and I wanted to share the exact technical point where the Google-side failure is occurring. I’ve already offered to supply the full HAR log, but since I haven’t had a response yet, here is a distilled summary of the relevant findings.*
The OAuth flow with Athom/Homey completes exactly as expected. After authentication and approval, Athom correctly redirects back to Google at:
https://oauth-redirect.googleusercontent.com/r/athom-cloud-assistant-devices?code=<redacted>
Google’s /r/athom-cloud-assistant-devices endpoint then immediately redirects to:
https://oauth-redirect.googleusercontent.com/a/com.google.android.apps.chromecast.app?redirect_state=<redacted>&service=athom-cloud-assistant-devices
This is where the process fails.
The /a/com.google.android.apps.chromecast.app endpoint returns a 404 Not Found from Google’s own servers.
This happens before the Google Home app gets anything back, so the entire failure is within Google’s OAuth/App Flip redirect infrastructure. Homey never sees a token exchange because the flow never reaches that stage.
I’ve since confirmed other smart-home integrations are hitting the same 404 on Android (Home Assistant, Philips Hue, and additional Homey cases - see below), which strongly suggests a misconfiguration or missing routing entry on the Android App Flip path for:
service = athom-cloud-assistant-devices
path = /a/com.google.android.apps.chromecast.app
iOS users appear unaffected, which is consistent with an Android App Flip redirect issue on Google’s side.
Given the above, can you confirm whether this broken /a/com.google.android.apps.chromecast.app redirect is a known issue, and whether the configuration for athom-cloud-assistant-devices can be corrected?
I’m still happy to provide the full HAR log with timestamps and request IDs - it captures the failure cleanly - but the summary above already isolates the exact point of failure.
Thanks, and looking forward to your update.
Supporting Evidence of Same 404 on Android
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A user of Home Assistant reports:
“The redirect to
/r/[project_id]works fine. But … then responds with another redirect to/a/com.google.android.apps.chromecast.app…” — 404 occurs on Android. Home Assistant Community -
A user of Philips Hue reports:
Attempting linking on Android: “I get a 404 error when it redirects me to
https://oauth-redirect.googleusercontent.com/a/com.google.android.apps.chromecast.app?…&service=meethue.com” Reddit
This is the end of the story, one day we dream of being able to use Google Assistant with Homey again.
The feature that appears to be used by the Google Home , works with Google connections, is this - App Flip for iOS | Google Account Linking | Google for Developers
Final thoughts and musings:
- As far as I can tell this is a Google issue.
- I suspect if I had an iPhone this would work
- Have Athom tested Homey connecting with Works with Google recently on an Android device
- Why doesn’t Homey allow you to make this connection from the Homey app as other apps appear to do
- Does anyone else get this specific issue (I wouldn’t disconnect your Homey if you’re on Android to test…)
- Am I the only one with this problem
