Amazon adds further capabilities to Echo devices with the introduction of 3 APIs-- Doorbell Event Source, Motion Sensor and Alexa.RTCSession Controller, allowing developers to connect the devices to security cameras and doorbells.
Initially available in the US as part of the Amazon Smart Home Skill API, such features allow 3rd party smart home apps to trigger Alexa actions through doorbell presses and motion alarms, among others. The Doorbell Event Source API plays announcement across all Echo devices, while Motion Sensor reports the state of an endpoint whenever motion is noticed within an area.
The final API, Alexa.RTCSessionController, allows smart cameras and doorbells to establish 2-way links with Alexa-enabled smart displays such as the Echo Show and Echo Spot. The API is compatible with WebRTC-compliant cameras and 3Ps using a WebRTC bridge to connect to Alexa. Half-duplex cameras cannot process Alexa voice controls, but get push-to-talk capabilities on the Echo Show and Echo Spot.
