Automations are a way to automate tasks and device settings in a home. Automations have been available in the Google Home ecosystem as Routines in the Google Home app (GHA) and through the automation script editor on Google Home for web.
Now, Automations in the Google Home ecosystem are available through the Home APIs. They use the same basic concepts used in GHA Routines and the script editor, but with enhanced features and capabilities only possible through the Home APIs, including:
- Access to all Matter standard and smart home traits for a device, as presented in the Home APIs.
- Support for sequential, parallel, and select execution flows.
Automations are written using Automation DSL, a domain-specific language designed for building automations in Kotlin.
Any traits and types that you intend to use in your app with the Device & Structure or Automation APIs must be registered at initialization. See Initialize the home.
Developer journey
The Automation API is one portion of a larger development journey. It comes after integrating the Structure and Device APIs to ensure that when a user wants to use an automation, they can do so.
- The developer plans their automation, and defines it using the Automation DSL.
- The developer embeds the automation definition in a Kotlin Android app.
- The app presents automations to a user based on information about their
devices, including traits, attributes, commands, and events, gathered using
the Discovery API or Device API.
- With the Discovery API, the app can generate a draft automation customized to the device types and traits present in the user's structure, with or without the user's input.
- The Device API can provide most of the same information as the Discovery API, but it's not optimized for automation use cases. See Compare the Device API and Discovery API for more details.
- The app creates the actual automation that is keyed to the selected structure.
- The automation is now available in the user's structure and can be executed or deleted using Structure API methods.
The user may create new instances of the automation at any time, selecting a different structure or, depending on the app logic, perhaps a different set of devices. Each time they do so, the app generates a new instance of the automation.
In the most basic scenario, you might suggest to your users a predefined automation that performs a relatively basic task. Alternatively, you could present a skeleton of an automation that the user customizes to meet their needs. Or you could write an open-ended automation editor that allows the user to construct complex automations using all the building blocks available in the Automation API.
Resource Limits
The following limits apply to automations in the Home APIs:
| Metric | Limit |
|---|---|
| Maximum number of automations per structure | 64 |
| Maximum number of nodes per automation | 128 |
| Maximum number of expression nodes per automation | 64 |
| Maximum number of automation instances per structure | 1024 |
| Maximum number of automation instances per developer per structure | 64 |
| Maximum number of executions per structure per day | 1024 |
| Maximum number of executions per developer per structure per day | 128 |