Smart home intents are simple messaging objects that describe what Cloud-to-cloud integration to perform such as turn on a light or cast audio to a speaker.
All of the smart home intents are contained in the
action.devices
namespace and you must provide fulfillment for them. Whenever
Google Assistant sends an intent to fulfillment, a user's
third-party OAuth 2 access token is passed in the Authorization header.
These are the supported smart home intents:
SYNC
The action.devices.SYNC
intent is used to request the list of
smart home devices that the user has connected and are
available for use.
When a user sets up their devices with the Google Home app (GHA), they also
get authenticated to your cloud infrastructure. Then,
Assistant receives an OAuth2 token. At this point,
Assistant sends a action.devices.SYNC
intent to your
fulfillment to retrieve the initial list of user devices and capabilities from
your cloud infrastructure.
![This figure shows the interaction between the Google infrastructure
and the partner infrastructure. From the Google infrastructure there is a
list of partners that is available to the Assistant client app, which then
flows to the partner infrastructure to complete OAuth authentication. The OAuth
authentication on the partner side is the partner setup webview, OAuth webview,
optional settings ands terms, and partner cloud services. The partner infrastructure,
then returns the OAuth credentials to the Assistant client app. The partner
cloud services sends available devices and capabilities to Assistant services,
which then stores the information in the Home Graph.](https://developers.home.google.com/static/cloud-to-cloud/primer/images/smarthome001.png?authuser=2)
To avoid unlinking and relinking a user's account, you can send a request sync
to Assistant. This sends the action.devices.SYNC
intent
to your fulfillment to sync the list of devices and capabilities. See
Implement Request Sync for more
information.
![Flow diagram of a SYNC intent](https://developers.home.google.com/static/cloud-to-cloud/primer/images/smarthome002.png?authuser=2)
During local fulfillment setup, the
Local Home platform checks the SYNC
response from your
smart home Action's cloud fulfillment. To learn more about how
to modify your SYNC
response to support local fulfillment, see
Update SYNC response in cloud fulfillment.
QUERY
The action.devices.QUERY
intent is used to query the current state
of smart home devices.
When users are querying device status, to answer a question such as
Hey Google, what lights are on in the kitchen?,
Assistant sends a action.devices.QUERY
intent to your
fulfillment.
![Flow diagram of a QUERY intent](https://developers.home.google.com/static/cloud-to-cloud/primer/images/query-diagram.png?authuser=2)
For the best user experience, you should implement Report State to proactively report the current state of a user's devices directly to Google Home Graph. For example, this lets Assistant know if your user turned on a smart light with a physical light switch.
![Reporting device state using Report State](https://developers.home.google.com/static/cloud-to-cloud/primer/images/smarthome004.png?authuser=2)
EXECUTE
The action.devices.EXECUTE
intent is used to provide commands
to execute on smart home devices.
When users send commands to devices with Assistant, your
fulfillment receives a action.devices.EXECUTE
intent to your fulfilment that
describes the action and the devices to act upon. A user can execute an action
on a device with a command such as Hey Google, turn on my living room lights.
![Flow diagram of an EXECUTE intent](https://developers.home.google.com/static/cloud-to-cloud/primer/images/smarthome003.png?authuser=2)
DISCONNECT
The action.devices.DISCONNECT
intent is triggered to inform you
when a user has unlinked the app account from Assistant.
After receiving a action.devices.DISCONNECT
intent, you should not report
state for this user's devices.