What Is a Programmable Voice API?

Posted on August 22, 2023

A programmable voice API, an application program interface, enables two pieces of software to communicate. You can build voice applications and integrate calling into existing apps or systems, like customer relationship management (CRM) software. While flexible options, including messaging, chat, and self-service, have gained popularity, consumers still prefer to call a business for a fast response. According to a Business Wire survey, 7 out of 10 consumers rank voice calling among their top three preferred methods to communicate with businesses.

A voice API hosted by a cloud-based Voice over Internet Protocol (VoIP) platform allows you to create powerful voice applications or integrate voice calling into your company or client’s systems or software. It can provide business-enhancing benefits at a cost-effective price, including scalability, reliability, and enterprise-grade features. Selecting the right communication API provider will ensure your mission-critical voice applications run seamlessly.

How Are Businesses Using Programmable Voice APIs?

Businesses are adopting voice APIs to build voice applications and create a more productive and customer-focused experiences with voice-calling options in their applications. As a developer, you can create a voice solution for your client or company using an API, integrating calling into the organization’s existing systems or software, and creating voice applications to enhance business communications.

A voice API offers reliable calling and automation solutions to reduce resources spent on repetitive calls. Working with a cloud-based VoIP platform provides the company scalability, flexibility, and mobility. Businesses can add voice calling to improve the customer experience and enhance business operations.

How Does a Programmable Voice API Simplify Voice Integration Into Business Applications?

Developing an API from scratch can take days or weeks of coding and testing. A programmable voice API easily integrates into your current applications in a few lines of code, and most can be up and running in minutes.

APIs from reputable providers offer developer resources like SDKs, quickstarts, use cases, and examples. The resources can make it easy to configure the software for your client or business using your preferred programming languages like Python, .NET, and PHP. 

How Are Developers Using Voice APIs for Business?

An API can enhance a client’s existing software or systems by incorporating a new feature into an established process, saving the client time and the expense of adapting to a new software or system to achieve the same feature. Here are the most-common voice applications and integrations developers are building for their clients.

CRM Integration

Integrating voice into a CRM allows live representatives to take and make calls through the platform. When an inbound call is received, the agent can take the call using a telephony device or PC and record the call within the CRM, storing the customer’s phone number to create a customer profile. When a representative wants to call the customer back, they can find their name and phone number in the CRM and seamlessly make the call from the same platform.

Calling from Apps and Websites

You can integrate a click-to-call feature into your client’s app or website, allowing users and customers to contact the business quickly and conveniently. Businesses use a click-to-call feature on e-commerce and support websites and applications like ride-sharing and delivery apps. You can ensure that users will call the intended recipient by making a click-to-call button that dials the correct direct inward dialing (DID) recipient, enhancing the user experience. The app can also mask user phone numbers with a proxy phone number to ensure privacy when calling a driver or delivery person.

Automated Answering and IVRs

A voice API allows you to make a tailored automated answering or interactive voice response (IVR) experience. Companies with higher call volumes depend on answering systems to ensure callers don’t have to wait long to complete simple transactions, ask questions, or speak with a live representative. When customers reach your business or client’s IVR, they will be given a series of prompts to help them reach the intended information, transaction, or agent.

For instance, a financial institution can allow users to check their balance, lock a debit or credit card, or dispute a charge without speaking to a live representative. It can save the institution time and money, reducing call volumes and resolving repetitive calls before a customer will reach a live representative.

Voice Assistants

Businesses are adopting voice-enabled virtual assistants or voice assistants to improve productivity and enhance the customer experience. If you have used Siri, Alexa, or Google Assistant to make a phone call, request a song, or ask a question, you are already familiar with some of the voice assistant options available to consumers. You can use a voice API to integrate a voice-enabled assistant into your client or company’s app or device, such as a smart speaker.

According to a Statista finding reported by Forbes, there may be more than 8 billion voice assistants worldwide by 2024. It offers the advantages of a chatbot — accessibility, availability, and cost-effectiveness — with the convenience of taking requests, answering questions, and making calls hands-free 24/7 from a compatible internet-connected device.

Related: What is a voice application?

How to Choose the Right Voice API Provider for Your Application

When deciding on a voice API to integrate into your company or client’s app, CRM, or software, finding an excellent provider is essential to reducing stress on IT professionals and allowing the end user to communicate seamlessly through the software. According to DevOps Digest, over 84% of business leaders say partnerships with API providers are vital to their organization.


Most voice providers charge a monthly or annual fee for unlimited or a set number of calls. A metered payment plan allows your company to pay for only the minutes consumed during calls. Metered payment plans can generally help a corporation save money by preventing overcharging your company for call time it does not need. A metered plan will always provide your company’s users with the required call time.

Voice API providers also charge for features like business phone numbers, custom or vanity phone numbers, local calling, and toll-free calls. If specific calling features are necessary for your company’s app, consider a voice API provider that allows you to integrate these features at a low cost. 

For example, toll-free calling can help your company or client avoid carrier-specific fees that may result in unexpected costs. A custom phone number may also be essential for your company to integrate a recognizable number.


As discussed above, implementing voice into software from scratch can consume valuable developer resources and may require an in-house PBX or business phone system. An API is a cost and time-efficient choice, but it helps to consider how well it will integrate into your software. Communication APIs with representational state transfer (REST) architecture consume fewer bandwidth resources over HTTP, work with most programming languages and use simple and uniform commands. REST APIs are preferred for web communication because they are lightweight and compatible with popular data types like XML.

A voice API can generally be implemented into your existing software using a few lines of code, but documentation can be helpful. Look for an API provider that offers developer resources like quickstarts, code examples, and SDKs to help you get your voice-enabled app up and running using your preferred programming language. The platform may also offer microservices in Docker containers for easy integration.


A voice API provider should have the resources to support your company and its app as it grows. With a reputable cloud-based VoIP provider, your voice application will be able to dynamically scale with the volume of inbound calls your client or company receives. An administrator can also add phone numbers and users from a simple web portal.

A scalable voice API provider will be able to provide unified communications integration in an API solution for adding email, SMS, voice, and video to your company’s app. A platform with a worldwide network will ensure that callers receive a consistent and high-quality calling experience, regardless of their location.


Reliability is a primary concern for business communications, requiring minimal downtime and 24/7 availability. When you choose a voice API to integrate into your company’s app or system, the provider should have a reliable and resilient network to make calls. 

A voice API platform should offer failover options to ensure inbound calls can failover to another physical network if the current network is interrupted. A resilient network combined with the inherent mobility of a cloud-based voice solution provides enhanced business continuity

For example, a cloud-based voice service will allow your client to switch to a remote work environment if a natural disaster forces employees to work remotely. VoIP solutions require only a telephony device, such as a mobile phone, and a stable internet connection to make and receive calls from the voice application.

A reliable voice API platform will also provide security, monitoring your client or company’s voice service for malicious calls such as toll fraud. You or an administrator can allow or deny specific destinations and inbound sources from a simple web portal.

Related: Is VoIP a reliable solution for business communication?


When considering a voice API provider, look for a carrier-grade experience. The voice service provider should offer the features you need to integrate into your company’s app or software. Session Initiation Protocol (SIP) is a feature that allows your VoIP traffic, chat, messages, and video to share a SIP trunk for nearly unlimited simultaneous communication channels. It is ideal for organizations that require flexibility and low-cost communications for a distributed workforce.

You can enhance your client or company’s productivity with call tracking capabilities and access to caller information through the call detail record (CDR). Remote call forwarding can ensure fewer calls are missed by your client or company, automatically forwarding inbound calls to another device like a mobile phone to ensure the intended recipient is reached.

An ideal voice API provider lets you quickly port in numbers and choose a custom business phone number from a simple web portal. Voice platforms also allow the business to change the name and number displayed on the user’s caller ID to easily identify the company’s phone calls, or mask users’ phone numbers to provide privacy for sensitive calls.

Advantages Voice APIs for Business

While simple integration into your company’s software is likely your main reason for choosing a programmable voice API, it can also provide other advantages. Using a voice API offers you and your end client some valuable benefits:

  • Deploy containerized voice instances to improve business voice efficiency and security
  • Click-to-call integration into an app or CRM
  • Mobility outside of the office with VoIP-enabled mobile devices
  • Carrier-grade reliability and uptime maintained by a world-class cloud-based provider
  • Collaborative business features like conference calling
  • Tracking and recording calls for analysis and quality assurance
  • Allow your company to bring its own devices, carrier, and phone number
  • Mask names and phone numbers with relevant business identifiers

Optimize Your Mission-Critical Voice Applications With a Reliable Communication API

A voice API is an efficient solution for integrating voice service into an app, CRM, or business system. It saves you or your development team hours of coding and gives you access to carrier-grade service with your existing devices and business phone systems. Voice APIs allow for scaling and automation to position your company or client’s app for long-term success.

With a voice API, you can implement calling in a few lines of code and have your voice service up and running in minutes. Your company or client will have access to productivity-increasing features and a worldwide network of voice communication centers, promising consistently high-quality calls worldwide for a better customer experience. 

Learn more about Flowroute APIs and patented HyperNetwork™ for guaranteed delivery for business continuity and near-unlimited scalability.