There’s a short answer and a long answer.
The short answer is that as of November 2015 there are two official ways to integrate SmartThings and Echo.
Method 1: Using IFTTT
The first is just by using IFTTT. Both Alexa and SmartThings have an IFTTT channel, so it’s super easy to control any switch in the smartthings channel just by using a “trigger” command in the Alexa channel. These are the commands that start with “Alexa, trigger…” And then any phrase you want to use.
This method allows you to control anything that you can do through the smartthings IFTTT channel, including locks and relays which are not recognized by Echo itself.
Also, if you use a virtual switch you can assign a Routine or smart app to that switch going on, and so that way you can control other stuff that SmartThings can do. Echo thinks it’s just turning on a switch, but that switch turning on then causes SmartThings to do whatever you set up.
Method 2: The official SmartThings/echo integration
There is a separate official integration which doesn’t require using IFTTT. Those commands use a different format “Alexa, turn on…” You don’t need to use the trigger word. And you can use the same virtual switch trick to set up echo to control mode changes or routines or whatever.
(Know that if you use this method you will have to individually “authorize” each SmartThings-controlled device to allow echo to control it. Then if you ever make any changes to that authorization list, you have to have echo rediscover the devices to get the updated version of the list.
(I just mention that now because it seems to be the most frequent question we get: someone sets up echo and smartthings just fine the first time with the official integration, and then a couple of days later they want to add an additional device, and they can’t figure out why echo doesn’t know about it. It’s just because they forgot the authorization step.)
No individual device authorization is required for the IFTTT method.
Also notice that echo does not recognize every kind of device. At the current time it can’t do locks with this method unless you use a virtual switch as a go-between. In contrast, method one can do anything you can do through the smartthings IFTTT channel, including locks.
On the other hand, because method two individually identifies each device of a recognized device class to echo, you can use it to combine smartthings-controlled devices with devices managed by other controllers and put them all in one echo group. So both methods have their uses.
Here’s the FAQ on both:
And, yes, that was the short answer. You’ll understand when you see the FAQ. 