Provide an API to get alexa user id using Alexa skill client
Our service needs account linking to work. Implementing OAuth2 is a lot of work. Using LWA is awkward since the user has already signed in Amazon and also requires the user to LWA in our app again. Using user's email is another way to do it, with the same down side that the user has to LWA in our app. All these force users to give up information that's is not really necessary.
I propose to let apps use Alexa user id to authenticate the user. This way users don't need to do anything on Alexa side besides enabling our skill. In our app, the user sign in using the Alexa client so we could associate the Alexa user id with the current user.