Voice API

Develop voice applications on your own infrastructure

Apifonica Voice API lets you integrate telephony into your own applications using standard web technologies such as HTTP(S) and REST. Connect business systems, automate call handling and develop custom voice applications on top of the cloud telecom platform.

Whether you are developing IVR systems, call routing logic, outbound campaigns or AI-powered voice applications, the Voice API gives you direct programmatic control over your telephony.

Develop your own voice applications

The Voice API enables developers to integrate speech services and business applications directly into telephony. Using our Developer API as a web-based programming interface, you can create communications workflows that run on your own infrastructure while using the reliability of our telecom platform.

The API surface includes 9 Call Control building blocks, 11 Voice APIs (HTTPS/REST), an ACD API and a Number-Order API.

Receive incoming calls

Receive notifications whenever a call reaches your number and decide how it should be handled. Your application can play messages, launch IVR menus, forward calls or trigger custom business logic.

Outbound calling

Start calls programmatically from your application. Once the called party answers, the platform requests instructions from your application to determine the next action.

Bridge calls

Connect two call participants under the control of your application and manage call routing dynamically.

Create IVR menus

Design interactive voice response menus by detecting keypad input and routing callers according to their selections.

Automatic Speech Recognition (ASR)

Integrate AI-powered speech recognition to interpret spoken language, automate voice interactions and personalise customer conversations. Speech engines from Google, Microsoft and Amazon are connected through one API.

Voicebot Connector

Connect conversational AI platforms through the Voice API. The Voicebot Connector lets you bring your own LLM – Claude, Gemini, Mistral or Dialogflow – while the platform handles the voice and telephony layer.

Text-to-Speech (TTS)

Convert text into natural speech using built-in TTS services from Google, Microsoft and Amazon – connected through one API.

SIP Trunk integration

Link and control SIP trunks directly within your Voice API call routing workflows.

Play media

Play announcements, waiting music or other audio files in formats such as MP3 or WAV during a call.

Call recordings

Start and stop call recordings programmatically whenever required.

Voice API removes telecom complexity

Voice APIs do not introduce new telephony capabilities. They make existing telecom functions directly accessible to developers through familiar web technologies.

If your business applications need to interact with your telephony environment, the Voice API provides a straightforward integration layer without specialist telecom expertise.

Why Voice APIs matter

Modern cloud applications rely on open, standardised interfaces instead of proprietary telecom hardware and software.

Voice APIs allow business applications to connect directly with telecom services through cloud communication providers, removing the need to operate your own telecom infrastructure.

This approach lets teams develop, deploy and scale communications applications while keeping development focused on business logic rather than telecom protocols.

What is an API?

An Application Programming Interface (API) is a standard software interface that allows applications to communicate with other systems.

In the context of communications, APIs connect business applications with telecom services, making it possible to develop voice-enabled applications regardless of the underlying systems or their location.

How the Voice API works

A Voice API, sometimes referred to as a Speech API, provides a collection of functions that allow software applications to initiate and receive phone calls without requiring developers to understand telecom protocols.

The platform acts as the interface between your application and the telecom network. The underlying network is a fully owned telecom backbone operated by a licensed German telecom carrier - not resold capacity.

Your application controls how calls are created and handled – from routing inbound calls to operating a global contact centre that distributes thousands of calls across multiple teams and locations.

For advanced and dynamic call handling, the Call Control functionality serves as the central component of the Voice API.

Use case

Cloud contact centre

An 0800 number immediately communicates customer focus and service quality. Because calls are free for the caller, customers are more likely to contact your business, whether they need support, want to place an order or have a sales enquiry.

As the business, you simply cover the cost of incoming calls. We can quickly assign an easy-to-remember 0800 number from our available pool or transfer your existing number through our free number porting service.

Applications can automatically answer incoming calls, identify customer needs, route conversations to the appropriate agent and integrate directly with CRM, ERP or other business systems.

Because routing logic is entirely software-driven, endpoints no longer need to be located in the same office. This enables flexible, cloud-based contact centres that scale and adapt without added maintenance overhead.

Developer Web API

The Developer Web API allows you to run communications applications entirely on your own servers while controlling the platform through standard web technologies.

Using the familiar request-response model, your application exchanges instructions with the platform to process calls in real time.

The Web API is particularly useful when your application needs access to existing databases, backend services or custom software libraries.

This approach provides deep backend integration while allowing you to use your own hosting environment and infrastructure.

Direct integration into your existing number routing.

You can perform actions such as:

Talk to our experts

Schedule a meeting to review your telephony setup and plan your voice infrastructure

After submitting the form, you will receive a response within one business day.

30 minute discovery session

A focused discussion on your current telephony, call volumes and the markets you operate in.

Live platform walkthrough

See how SIP Trunk, Cloud-PBX, ACD and the Voice API work with your existing phone system.

Migration discussion

Review number porting, connection to your PBX or contact centre software and rollout timeline.

Our clients