Telnyx Launches Programmable Voice API: Call Control

Telnyx, the world’s only self-service, full-stack communications platform — with numbers in more than 140 countries around the globe — today announced the launch of its Programmable Voice API: Voice API . With enterprise-grade reliability, a full feature set, integration tools and documentation, the launch solidifies Telnyx as a leading CPaaS provider.

About Telnyx Voice Products

As a software-driven licensed telecom operator with its own network, Telnyx offers 6,000+ business customers unprecedented access to and control of the very fabric of communications — the public switched telephone network (PSTN) — enabling them to build differentiated solutions and products not possible through other CPaaS providers or incumbent telecom operators.

What is Call Control and how does it work with Telnyx?

Using the Call Control voice API, customers can build highly customizable calling experiences into their own applications. Key features include the ability to answer or transfer calls, play recorded messages, record calls, respond to prompts via keypad or voice, stream media to multiple recipients, automatically detect answering machines (AMD), manage conferences, and more.

One key advantage of Call Control is that developers don’t need telecom expertise to build voice applications. The platform executes all telephony functions, so developers can focus on designing an engaging calling experience.

Call Control can empower intelligent voice experiences across a wide variety of use cases:

• Contact center software
• UCaaS platforms
• Cloud-based IVRs
• Call tracking solutions
• Conversational AI applications
• Voice notifications and alerts
• Language services

Any workforce application with embedded collaboration or communication requirements can leverage Call Control.

Telnyx’s solution is unique for a number of reasons. First, Telnyx manages a private network environment with control over call routing and core communications functionality. Using an edge-stack approach, Telnyx also leverages global PoPs to process data in the location nearest the customer application, which means inputs can be received, acted on, and then Telnyx can provide webhooks back to those applications in a fraction of a second.

Additionally, the Telnyx voice API can receive real-time commands throughout the call for interactive control. This is in stark contrast to most competitor solutions, which require pre-scripted commands at the beginning of a call. Telnyx customers can also stream call media to multiple recipients — including AI engines and contact center auditing agents — in real time. As a result, call media can be duplicated, delivered, analyzed and returned instantly.

Lastly, Telnyx developed an XML translator tool called TeXML Translator. TeXML Translator removes any barriers to switching from competitor XML-based solutions, allowing customers to build applications using Telnyx numbers — fast. Those that already have an XML application can simply configure their Telnyx portal connection to point at their XML endpoint. When a call comes in, Telnyx does the rest. Customers can also write new XML applications in minutes using simple TeXML commands.

The tool aims to make it fast and simple for customers wanting to integrate voice into their applications without the need for extensive development time and resources. In addition, Telnyx has developed SDKs in popular programming languages and application-based guides to further enable faster, streamlined customer migration.

Over the years, Telnyx has built a more robust offering through vertical integration — converging the CPaaS, telecom service provider and telecom equipment manufacturer business models. The company offers customers a secure, highly available platform that traditional operators cannot. It has deployed a global network, leverages a multi-cloud infrastructure, procures numbering resources directly from regulatory authorities, and interfaces with other carriers as a peer. Telnyx has outpaced competitors, while offering unique solutions for previously underserved areas of the market.

Get started with Telnyx Call Control by signing up for an account, or chat to our voice API experts to find out how Call Control can meet your intelligent communications needs.

FAQ

What is programmable voice? Programmable voice is API-driven telephony that lets software place, receive, and control voice interactions in real time. Developers use webhooks, media streams, speech-to-text, and text-to-speech to customize flows and integrate data.

How does programmable voice differ from VoIP or a traditional PBX? VoIP and PBX focus on transporting voice, while programmable voice exposes granular call control, media access, and event hooks. This enables dynamic IVRs, agent assist, and AI-driven workflows without hardware lock-in.

What trends are shaping programmable voice in 2025? Real-time AI is moving on-call with faster speech recognition, expressive TTS, and low-latency orchestration for human-like conversations. Enterprises are also prioritizing global coverage, data locality, and security frameworks like STIR/SHAKEN to keep trust high.

What are common enterprise use cases for programmable voice? Teams automate inbound IVRs, outbound reminders, collections, authentication, agent assist, and post-call surveys. Many pair voice flows with MMS messaging to deliver receipts, images, or directions that reinforce the conversation.

How should I evaluate latency and quality for programmable voice? Measure round-trip time, jitter, and packet loss, and require HD codecs and noise suppression for clarity. Test across regions during peak loads to confirm stable responses under real traffic.

How does programmable voice fit with SMS and MMS in an omnichannel strategy? Use voice for complex or urgent issues, then reinforce the outcome with a text that matches the payload requirements. Plan your channel mix by understanding SMS vs. MMS differences in media support, character limits, and pricing.

Can programmable voice support large-scale notifications and campaigns? Voice can deliver time-critical alerts, then a follow-up text can capture confirmations or provide visuals. For message fan-out after a call, choose MMS group or broadcast messaging based on whether recipients should reply to the group or only to the sender.