What this book covers

Chapter 1, Working with TwiML, covers TwiML, which is Twilio's XML-based language, that directs how Twilio handles incoming calls and SMSes and places outgoing calls. The actions in TwiML are called verbs, and we'll look at all of them and how they're used.

Chapter 2, Exploring the REST API, takes you through interacting with the data in your Twilio account, as well as placing calls and sending SMS messages. You'll learn how to set up the PHP API library, how to interact directly with the API using a tool called Postman, and how to use the API's most useful features.

Chapter 3, Calling in the Browser with Twilio Client, introduces Twilio Client, which is a way of making and receiving phone calls directly within your applications, in a browser or mobile app, without using a physical phone. You'll discover how this works at a high level and how to practically implement it in your code.

Chapter 4, Twilio in the Real World, takes you through building two real Twilio applications: a callback request tool for your website and a simple conference calling service with fully explained code samples.

Chapter 5, Twilio in your language, goes beyond the PHP code we've used in most of the book, showing how to download and configure Twilio's API libraries for Ruby, Python, C#, Java, Node, and Salesforce.com.

Chapter 6, Securing your Twilio App, helps you keep your application and Twilio credit secure with two-factor authentication on your Twilio account. We will verify that the requests you're receiving really come from Twilio and will set up a circuit breaker to detect bugs and account misuse.

Chapter 7, Testing, Debugging, and Deploying Twilio Apps, explains how to test your apps before you release them into the wild and then how to monitor and maintain them later using the App Monitor and Request Inspector.

Chapter 8, Online Resources, contains some helpful links to help you get the most from this book and follow Twilio's best practices.