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Programmable Voice SDK

Twilio Programmable Voice SDK makes it easy for you to add voice-over-IP (VoIP) calling into your web and native mobile applications quickly.

Get Started on Android

Get Started on iOS


In the Programmable Voice SDKs we use a new authentication/authorization mechanism for your application server to give your clients access to your voice applications. This is done by providing your app an Access Token, which governs the client application’s authentication session with your account in the Twilio cloud. Access Tokens are different from the Capability Tokens used in the previous versions of Twilio Client. Using a Capability Token in the Programmable Voice SDK will not work. Access Tokens, just like Capability Tokens before, are JWT tokens, but are using a new, more flexible format that is used across all the new Twilio SDKs.

The identity provided in the Access Token may only contain alpha-numeric and underscore characters. Other characters, including spaces, will result in undefined behavior.

Management Console

Developer tools and configuration options for Programmable Voice can be found in the Programmable Voice Dashboard. Use the console to create TwiML apps, update push credentials, view logs, and much more.

Getting Help

Since this is an early release product, we are anxious to hear your feedback and help you with any trouble you may encounter. For technical support, send a mail to

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