I am writing a smart home skill that will take a request (let's say Power) and then use the AWS IoT Shadow State service to communicate with an embedded device.
The embedded device will receive the delta request, update its state and then publish a final reported state. This will then be picked up by a IoT rule and then invoke a Lmabda to finally call the alexa event gateway with the deferred Response for the request.
The issue I am having is that I'm struggling to find a way to include the correlation token (I am assuming I am supposed to use the correlation token specified on the request and return it on the deferred Response I post to the event gateway). At the moment I am facing the prospect of round-tripping it to the device and back again which feels like massive overkill especially given the token is nearly 1kB in size (!?!?!?) and that's going to start causing me a headache on the embedded device.
I wanted to check if there was anything I was getting wrong with Async Response and/or anyone had a better/improved way of doing this.