My Smart Home skill receives a command and successfully sends an MQTT message to my hardware. This is working in the development environment where I am in control of the subscribed topic and know the 'Thing'. But when deployed commercially, how does the lambda function determine what physical device to access? Presumably the lambda needs to publish its commands to a specific thing - relevant to the whoever has the device and sends it an intent.
Where do we get this data from? Presumably the lambda must be sent this information from the API. No examples I can find appear to show how this works.