If your Nest thermostat, doorbell or camera reaches Home Assistant through the official Nest integration, its real-time updates depend on a Google Cloud Pub/Sub topic. Many older setups use a topic that Google hosts for you, with an ID in the form projects/sdm-prod/topics/enterprise-<project-id>. Google's Device Access documentation now carries a warning that event notifications will stop being published to those Google-hosted topics after 30 November 2026. After that date, a project still on one gets no real-time device state updates or trait events, so doorbell presses, motion and camera events would stop arriving.

What Google asks you to do

The fix is to create a Pub/Sub topic in your own Google Cloud project, give Google's [email protected] group the Pub/Sub Publisher role on it, then disable the old topic in the Device Access Console and enable events again with the new one. Google says the switch does not invalidate existing access tokens or OAuth permissions. A self-hosted topic is billed at normal Pub/Sub rates, which include a free tier of 10 GB per month. If your project already uses a topic in your own Cloud project, nothing changes for you.

Home Assistant's side

Three pull requests prepare the Nest integration for the cut-off, and all of them are merged for Home Assistant 2026.11:

  • #187052 (merged 18 October) stops the setup flow from listing or querying Google-hosted sdm-prod topics, so new setups only see topics from your own project.
  • #187156 (merged 22 October) adds a Reconfigure option. It reuses your sign-in if it is still valid, lets you pick or create a topic and a subscription in your project, and deletes the old subscription when Home Assistant created it. Until now, changing the topic meant removing and adding the integration again.
  • #188119 (merged 23 October) raises a repair issue at start-up for any Nest entry without a self-hosted topic, telling you to run Reconfigure. It clears itself once you do. A second, separate repair appears if the subscription or the topic behind it has been deleted.

How to check now

Open the Device Access Console and look at the Pub/Sub topic of your project. If it starts with projects/sdm-prod/, you are affected. You can create the new topic ahead of time with the gcloud commands on Google's page, then switch Home Assistant over with Reconfigure once you are on 2026.11. That leaves the whole of November for the move, but the date is Google's and the integration cannot push it back.