I don't know, no one really does as this has never been tested in courts as far as I know. I believe the FSF would say that it's not a derivative work, as it doesn't interact with the Alexa code through complex data types. However, this is their own legal theory, not directly a part of any law or jurisprudence (as far as I know - if there is some case law on this topic, I would be very curious to read it).