Understanding how Alexa Skills work will help you get a feel for what you need to do as a part of the voice app development process, and what the Alexa service will do for you.
The first thing that happens is the customer says something to Alexa, usually to launch a skill. This is the utterance that Alexa will use to determine the next action.
Let’s use a Hello World example: The user would say “Alexa open Hello World”.
The utterance is sent to the Alexa service where speech recognition natural language understanding all take place and they interpret that and they in turn send your skill an intent that way. This is what the user wants to do.
In this case they said “Open Hello World”, I want to launch your skill the the service calls your back-end and you can do whatever logic you might want to do. This will be done in JSON it will send you a JSON request and then you send a JSON response back where you would say something like “Welcome to Hello World”.
You then go back through the Alexa service and it’ll compose the response that we want to give to customers.
If you take this example just a little bit deeper…instead of just saying “Hello World”, you can prompt the user and say “What’s your name?” so the user would reply.
The Alexa speech recognition service and the natural language understanding systems would kick in together to go see that the user just responded with their name and include that as a slot value so “Paul” is now the slot value, it’s the information, and this will be stored for you to go use so you it’ll send you a JSON request that says the slot value is Paul.
You can then compose a response, it goes back to Alexa service which creates the text-to-speech and then it’ll read it out to the customer so it says “Hey Paul, now you have some other abilities”.
Here is where you can choose to make the response include just text or it could include sound effects or it could include interjections like “Hey Paul” and could be a little more animated and you can further expand that further.
To get started, check out the Alexa Skills Kit here: https://developer.amazon.com/en-US/docs/alexa/ask-overviews/what-is-the-alexa-skills-kit.html
Check out these other Alexa skill guides to learn more.
Watch the following video by Paul Cutsinger from Alexa Developers to understand more about how Alexa skills work: