If I have created multiple Alexa skills, is there a userId that would remain the same across all the skills? Specifically, if user does an action in Skill 1, I'd like to be aware of it for Skills 2 and Skills 3... and essentially allow the skills to share the same DynamoDB table.
Ideally I wouldn't require the user to do any sort of login, but it would know it's the same user based on a unique identifier tied to their Amazon account.
No. About a year ago Amazon made specific changes to prevent you from doing that. You also can't identify a user who uninstalls your skill and then reinstalls it. You always get a new random user id.
The same thing has been happening for mobile development: Google and Apple are blocking access to anything that would allow you to ID a physical device, or to ID a user of different app installs without doing some sort of account linking - so I doubt Amazon is going to relax about this.
According to this part of the documentation, it should be possible by using the deviceId instead of userId:
device An object providing information about the device used to send the request. The device object contains both deviceId and supportedInterfaces properties. The deviceId property uniquely identifies the device. [...]
You find it as:
deviceId = this.event.context.System.device.deviceId
It is the same value you need to use for requesting the device address with the new address api. Hence, I don't see why it shouldn't work for your needs also.
