The Vonage Voice API allows users to make and receive phone calls, with features such as text-to-speech messages, streaming audio files into calls, forwarding, and placing calls in conferences. Zapier integrates this API, enabling users to create workflows that automate repetitive tasks by connecting two or more apps. The integration offers eight events: four triggers and four actions, which can be used to trigger a workflow when someone rings the Vonage number or initiate an outbound call. Triggers include polling and instant triggers, with all Vonage Voice triggers being instant triggers that start a workflow when an inbound call reaches one of the virtual numbers. Actions include creating text-to-speech calls, streaming audio files into calls, forwarding calls, and placing calls in conferences. Users can add these actions to their workflows to automate tasks such as sending reminders or notifications.