Amazon recently announced that it has updated the Alexa Smart Home Skill API to support new experiences it has added to its Alexa devices.
The new experiences include Routines, which allow customers to control multiple devices using a single voice command, as well as updates to Alexa's Groups feature, which will make it easier for Alexa smart home customers to control their devices without remembering their specific names.
To support these new experiences, Amazon has added new features to the Smart Home Skill API. These includes new Capability Interfaces, which describe a device's functionality, as well as the ability for developers to send Asynchronous messages from a device cloud to Alexa. Amazon says that support for asynchronous messages will give developers "greater flexibility for situations when your skill cannot provide an immediate response, such as when managing long running actions like locking a door." Previously, only skills running in AWS Lambda could send updates to Alexa.
Finally, the updated Smart Home Skill API now supports Proactive State Updates which will allow Alexa to present customers with state information at a lower latency when they ask about devices or check on them using the Alexa app.
Amazon says that "the updated Smart Home Skill API will be the basis for all future smart home enhancements" and is encouraging developers to update their Smart Home Skills to support the new experiences and make sure they're able to take advantage of future enhancements. To help developers make updates, Amazon has provided a migration guide which can be accessed here.