Twilio Voice SDK Call Message Events: User-Defined Messages (active calls) is now in Public Beta

The Twilio Programmable Voice SDKs now offer the new Call Message Events: User-Defined Messages and User-Defined Message Subscription resources for application developers. This release, available now in Public Beta on the latest major versions of Voice JS and iOS SDKs, supports relaying custom events to and from your backend to a registered Voice SDK Client on any active call - all within the Twilio platform. This closes the loop on our December ‘22 release by extending support for established (“in-progress”) calls to also support for calls in a ringing state. By leveraging the existing signaling connection, you no longer need to set up your own communication channel between your client-side and server-side applications. This unlocks a host of advanced use cases, including:

• Relaying (and taking action on) call progress events
• In-line text transcriptions
• Upgrading 2-party call to multi-party via Voice Conference
• Presenting valuable context in your application at the right time, such as quick text reply buttons in a mobile app

In coming releases we’ll bring this functionality to our Android SDK as well as explore options to provide “out-of-the-box” event subscriptions for common use cases. Check out the docs for more information on how to use the new functionality in your application. We can’t wait to see what you build!