I need to make a Custom Skill for the Alexa Skills Kit, which should be one echo device in every room. I need to get the device_id for every echo device. I heard this isn't possible, but maybe it changed, or if not is there any other way around.
You can do it now! context:System:device:deviceId
As far as I can tell it only works on real devices. So if you are testing in the developer's Skills Manager you don't get the field, but when used with a real Alexa device, it works.