Voice Messaging

What is voice API ?

Voice API is a tool used by software developers to make, receive and manage phone calls using an Application Programming Interface (API). A voice API brings together the Public Switched Telephone Network (PSTN) and applications connected to the internet.
There is no need for developers to have specialized telecommunications knowledge and hardware to build voice applications, as the voice API executes all the telephony functions, so developers can focus on designing an engaging customer experience.

APIs are built for a wide range of uses from a basic phone to phone calling, application to phone calling, global phone calling, Interactive Voice Response (IVR), conference calling, SIP interfacing, call recording, transcription, call tracking, and more.

Routee’s Voice API

Routee’s Voice API is easily integrable, very well documented, and incredibly cost-effective, enabling you to make and receive voice calls to and from any country across the world, quickly. We have all the right developer tools so you can build high-quality applications.
Let’s put a voice to your campaigns.

Using Routee’s API you can:

  • Send your Voice message using your custom audio file to a large number of recipients with a single call or use our text 2 speech engine to convert your desired written text into natural-sounding audio.
  • Use Routee’s contacts to group them quickly and easily
  • Schedule your campaign for a later time
  • Test your Voice campaign before sending it
  • Track the campaign

Text-2-Speech engine

Build a high-quality voice application using our Text-to-Speech tool and convert your written text to a natural-sounding voice. Our text-2-speech engine is the easiest way to construct a Voice message.
Simply type your desired message (maximum 1000 characters) then choose an available language and gender, and your high-quality voice message is ready for delivery.

The engine supports the following languages: Greek, Bulgarian, Polish, Hungarian, Swedish, German, English (British), English (US), Spanish (Castilian), Spanish (Latin American), French, Italian, Portuguese (Brazilian), Russian. It also offers the ability to choose between female and/or male voices.
Custom audio file*
Upload your audio file (in .wav format) if you wish to playback your message as a Voice message to your recipients.

*Routee currently supports only .wav files for Voice message playback.

How to get started?

You will just need a few lines of code and you are ready to make your first outgoing phone call with Routee’s Voice API. By adding a few more, your app will be able to respond to incoming callers.

The process for all programming languages will look like this:

  • Sign up to Routee and get your voice-enabled phone number.
  • Check and set up your development environment in order to make and receive phone calls.
  • Make an outbound call with Routee.
  • Receive and respond to an inbound phone call that reads a message to the caller, using our text-2-speech engine.

Now, choose your programming language and get started.

When sending a Voice Message, you have to set a sender id. The sender id must be numeric with the maximum number of characters limited to 16.


Routee charges per second of successful call (voice messaging). This means that you won't be charged for the calls the recipient does not answer.

What’s Next