I have 2 Nest Gen 3 thermostats that have worked fine through the Nest binding (SDM). A few days ago one of the thermostats stopped being updated and the logs showed errors “openhab nest sdm api error device … not found”. I tried restarting, removing the thing and scanning for new devices. Unfortunately the device was not detected.
Looking in the Nest app (that still works fine) I noticed that very recently the firmware was updated from version 5.9.5-2 (dated Mar 19, 2022) to 6.4-5 (dated Jun 17, 2025). The thermostat that is still working with the binding is still at 5.9.5-2.
I switched on debug logging but could not get any clues on the missing thermostat. It clearly finds only one when calling:
I did some further reading and found similar issues reported by HA users who had their thermostat automatically updated to 6.4-5. For some of them it started working again, not for me unfortunately.
In the end I decided to start from scratch and follow the Nest binding documentation to set everything up again. Things have slightly changed in the Google Cloud Console. Initially I could not get pub/sub working, following error is shown when adding a pub/sub topic to the project:
Device Access service cannot publish messages into the specified PubSub topic. Verify that sdm-publisher@googlegroups.com has the PubSub Publisher role in the PubSub topic. Make sure you have followed the prerequisites in the documentation ([link](https://developers.google.com/nest/device-access/subscribe-to-events))
Trick here is to add a Principal (sdm-publisher@googlegroups.com) to the Topics (tab), not the Subscriptions (tab), within the Google Pub/Sub API configuration page. On the Topics tab, click the 3 dot menu next to the topic you created, then select View Permissions. A sidebar menu will popup where you can add a Principal and give it the Pub/Sub Publisher role. You do not need any Principal configured on the subscription-level, only the topic-level.
Has been a while since I had to go through the Google Cloud Console “labyrinth”, and probably I will have to do this again when the other Thermostat decides to update itself. I noticed that the newer firmware (after years of Google not fixing any of the issues with the thermostat) has some additional features when accessed through the Google Home app.
I was experiencing the same problem with my Nest Gen 3 thermostat after the software update beginning of July.
In addition to adding sdm-publisher@googlegroups.com as a Principal to the topics group as mentioned by @mvbergen , I also had to do a one-time trigger to get the Nest to publish events again.
I had this problem - or something similar. My Nest thermostat integration stopped working in July but I didn’t notice until I upgraded to OH 5. I have firmware 6.4-5 now and assume that upgrade was the cause.
In my OH5 log I saw a different message
SDM API error: Device enterprises/<project_id>/devices/<device_id> not found
The SDM account and thermostat things both showed as online and connected, including pub/sub. But metrics in GCloud console showed only 404s and OH was not up to date or receiving changes.
I couldn’t add sdm-publisher@googlegroups.com to the Topics tab in Google Pub/Sub configuration because I don’t have sufficient access to the topic (seems to be owned by the SDM product).
My Nest’s device ID seems to have changed during the firmware update. For me the fix was to delete the thing and repeat the steps from the binding documentation related to getting an authorization code . Doing so seems to have granted access to the thermostat by it’s new ID. Client IDs, secrets, etc all unchanged - just a new auth code.
Seems to be a range of issues and fixes here, arising from the Nest fw upgrade
