We all know that if we enabled the SmartThings skill in Alexa we can access our SmartThings devices in Alexa. Which is very useful.
However is there anyway to achieve the opposite. I have a few devices that are connected directly to Alexa and would like to access these from SmartThings (and webCoRe). Has anyone been successful in achieving this?
See the FAQ. This describes how to use the official echo routines (not smartthings routines) so that you can initiate something from the smartthings side and have echo do it.
There are also several community created smart apps which can do it but have a much more complex set up than the method described in the FAQ. In general you will have to get an Amazon developers account. But for people who have a strong technical background, they are definitely worth looking into.
These include
EchoSistant
Ask Alexa
And Echo Speaks
What exactly do you mean by “access”? And what kinds of devices are you wanting to access?
There’s no easy way to expose non ST devices that are connected to your Alexa account directly to ST, but there are several workarounds for various devices/types of access.
If you want to trigger something in ST based on the action of an Alexa connected device, you can create a virtual device in ST, add it to Alexa, and create an Alexa routine that triggers the virtual device, which is monitored by ST/webCoRE. You can also do the reverse and have a virtual switch in ST that triggers an Alexa routine. One issue with this is that Alexa routines are very limited in what they can be triggered by and what actions they can take in response to a trigger.
And if something can connect to Alexa, then there’s a high likelihood that it can also connect to other IoT services like IFTTT, which can be used to expose it to ST/webCoRE, usually in much more useful ways than the clunky workarounds described above.
I’ve got all these apps but they don’t seem to do what I want.
I have a device that I have connected to Alexa only. I want to be able to access it from within ST.
So say it’s a light (for arguments sake). I want to be able to use that light as as a device in webCoRe.
That kind of access (direct device control) will likely not be available for a LONG time, if ever. The closest you’ll get is Echo Speaks which can trigger an Alexa routine.
Amazon keeps thier ecosystem close to the vest for the longest time we couldn’t even get what we have now. That changed so I won’t say what you want will never happen. Just being pragmatic, (and not based on any insider knowledge) I personally believe you’ll see the SmartThings new app have feature parity with Classic before this ever happens. 
Looks like I should be able to get what I done with a virtual switch and echo speaks action running a routine in Alexa that controls the device that’s in Alexa.
But of a messy workaround but at least it’s something. Thanks for chewing the fat with me guys.
Keep in mind that switches currently can’t be used to trigger Alexa routines, so you may need to use a virtual contact sensor or virtual motion sensor instead. And before you go through the trouble of making the virtual sensor and writing a webCoRE piston, make sure the device you want to control is available as an action in an Alexa routine. Just because a device is able to be controlled by Alexa doesn’t mean it’s necessarily available as an action in Alexa routines.
If you read the FAQ linked to above, you will see that it includes the DTH for a virtual device which is both a sensor and a switch.
So it can be used as a sensor to trigger an Echo routine, but you can turn it on and off with any SmartThings automation or a scene or SmartLighting. Or WebCore, of course. 
(On = open, Off =closed)
All detailed in the FAQ.
thanks @JDRoberts I do already have a few things working like this, I was curious if there was a way to control the Alexa devices directly from ST without having to go through anything else. I have my answer 
I will try and do some work on this over the weekend to get it doing what I want, however in this instance its not as easy, but I am sure with a bit of thought and detailed design I’ll manage it 
had a look at the FAQ ( FAQ: Can I trigger an Echo Action without Speaking to It? ) but can’t see the DTH you mention, think it might just be one of those days for me.
edit - found it, thanks
edit 2 - I now have working what I wanted… thanks so much @JDRoberts