Voice API Concepts

These pages explain key concepts and terminology for the Voice API:

  • Authentication with JWTs - interaction with the Voice API are authenticated using JWTs (JSON Web Tokens). The libraries handle JWT generation using a unique Vonage Voice Application ID and a Private Key. For more information see authenticating your applications. You can also find more information on generating JWTs using the Vonage Server SDKs here.
  • Vonage Voice Applications - Vonage Voice Applications represent a one-to-one mapping with the application that you are building. They contain configuration such as virtual numbers and webhook callback URLs. You can create Vonage Voice Applications using the Vonage Dashboard, the Vonage CLI, or via the Application API.
  • Webhooks - HTTP requests are made to your application web server so that you can act upon them. For example, an incoming call will send a webhook.
  • Call Flow - Learn how Call Control Objects are used throughout the flow of a call.
  • Call Control Objects - Learn more about Call Control Objects, a set of actions that instruct Vonage how to control the call to your Vonage application.
  • Numbers - The key concepts of using phone numbers in the Vonage Voice API.
  • Endpoints - When connecting a call, you can connect to another phone number, a sip endpoint or a websocket. These are known as endpoints.
  • Text to Speech - Using our Text-To-Speech engine, you can play machine-generated speech to your callers.
  • Customizing Spoken Text - Use Speech Synthesis Markup Language (SSML) to control how text-to-speech is read out.
  • Speech to Text - Capture user input by converting user speech to text form during a call.
  • DTMF - Capture user input by detecting DTMF tones (button presses) during a call.
  • Call Recording - Recording audio input from a caller or recording the conversation between two callers.
  • Web Sockets - You can connect the audio of a call to a WebSocket to work with it in real time.
  • Contact Center Intelligence - Learn how to enhance your contact center solution with Voice API.
  • Fraud Prevention - Protect your Voice API applications from fraud.