The Google Home Graph Viewer is a tool to check the state of devices in the Home Graph of a specific user. It obtains data from your Home Graph and presents it to you, allowing you to verify the data that is stored in it.
Follow the instructions below to test Report State by using the Home Graph Viewer:
Sign in to Google using the top-right corner button.
In the Project ID field, enter the project identifier for your smart home Action, and click the Sync button:
All of your devices are listed along with their state information. Once the list is populated, you can use the Sync button to refresh device states.