Most of the apps built using Voximplant have some client application that uses our Web or Mobile SDK, or other types of endpoints to communicate with Voximplant (like SIP client), but there are a couple of scenarios when no client application is involved. The most common one is callback scenario when the platform makes calls to different destinations and joins these calls when required. Another option is automated notifications or surveys when you want to call your customer and playback an important message or receive their feedback for a product or service. A special part of HTTP API available for Voximplant developers that makes these scenarios possible and easy to implement is Control API. A description of the API is available here and a “How To” guide can be found here. Learn more in our blog post about Control API.