This book will introduce you to the exciting topic of voice user interfaces, building applications known as “skills” for the Alexa platform. We’ll start where all good learning projects start, with a simple “Hello World” skill that we’ll deploy to Alexa and talk to. Then, before diving in deep, you’ll learn techniques for testing Alexa skills, with both semi-automated and completely automated tests.

Next, you’ll learn how to parameterize our conversations with Alexa using slots. When the user leaves out important information or says something that doesn’t make sense, you’ll learn how to create dialogs where Alexa can elicit missing details and validate that the information given is acceptable.

Often, voice interfaces must collaborate with other applications. We’ll explore options for integrating Alexa skills with external applications and APIs. Next, we’ll look at how to change how Alexa speaks and sounds, and even include special sound effects and music in her responses using the Speech Synthesis Markup Language (SSML). That will lead right into a discussion of how to add localization to our skills so that Alexa can speak in the user’s own language (and even change her voice to include the language’s accent).

Then we’ll see how voice-first applications aren’t necessarily voice-only applications, by creating visual experiences that complement Alexa’s vocal responses when our skill is launched on screen-enabled devices such as Echo Show and Fire TV. Following our exploration of visual interfaces, we’ll see how skills can act in response to out-of-band events when the user isn’t actively using the skill. This includes handling events that are triggered when the user modifies the skill’s settings as well as notifying the user of events.

Next, you’ll learn how to monetize skills by offering in-skill purchases, allowing the user to purchase goods, both tangible and virtual. We’ll then unleash our skill to the world by publishing it. You’ll learn what the requirements for publication are as well as perform some last-minute fine tuning to ensure that our skill is ready for real-world use.

Finally, we’ll have a look at a relatively new way to create rich conversational interactions using Alexa Conversations. Like Dialogs we learned about earlier in the book, Conversations involve a question and answer session between Alexa and the user to achieve some outcome. But where Conversations shine is in how they allow the user to change their answers and take tangents in the conversational flow.