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Voice posts

  • By Robert Hockley
    Creating a Emergency Outage IVR Response in Twilio Studio Article Header

    If you are part of a team that ensures the smooth operation of a contact center, you may be tasked with planning for the unknown. Surprises or rapidly changing situations are times when the value of a cloud-based voice solution shows through. In the case of an emergency — such as a weather-related closure, a facilities problem, or a personnel challenge — you may need to remotely activate a temporary change to your voice responder.

    In this article, I will use Twilio’s IVR solution to create an emergency outage message that can play for incoming callers, notifying them of an unmanned queue. This message can save customers time and frustration and give you space to ensure the health and safety of your team. If you follow along with me through the steps I present here, you’ll have a working outage message for your selected Twilio phone numbers.

    Tutorial prerequisites

    To …

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  • By Mark Lewin
    Create a Cold War-Era Numbers Station with Twilio Voice and Python Flask Create a Cold War-Era Numbers Station with Twilio Voice and Python Flask

    Put on your fedora and dark glasses, because you’re about to become a Cold War-era numbers station operator!

    What is a numbers station, I hear you ask? A numbers station is a radio station in the shortwave frequency band that periodically reads out a sequence of numbers, popularly believed to be a secret code for intelligence officers listening for encrypted information. Numbers stations appeared during World War I and are likely to have become much more prevalent during the Cold War.

    In the past, the numbers were often spoken in what sounded like a creepy voice, probably due to the poor radio transmission quality available at the time. You can listen to a few recent examples of numbers station transmissions on the Crypto Museum's website. Some numbers stations survive to this very day.

    Since many people enjoy cracking secret codes, I thought it would be fun to show you …

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  • By Niels Swimberghe
    Handle No-Answer Scenarios with Voicemail and Callback Handle no-answer scenarios header

    Have you ever called a company but instead of being connected to a representative, you were told no one was available and the call abruptly ended? Have you ever had to stay on the phone waiting for hours until a customer representative finally is able to take your call?

    Unfortunately, those bad user experiences are too common and is why people hate calling businesses, but it doesn't have to be this way. Using Twilio Programmable Voice, you can build a better experience! Even if there's nobody available to take the call right now, you could ask them to leave a message and their phone number so you can give them a callback later on.


    This tutorial is for developers at any experience level. Prior experience with the following technologies is recommended, but not required:

    • C#
    • .NET
    • ASP.NET Core

    You’ll need the following development resources to build and run the …

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  • By Al Kiramoto
    Quickly Enable Your Employees to Work from Home Using Twilio Programmable Voice Enable WFH Quickly Hero

    If your PBX solution does not natively allow for remote working and you need to act fast, this solution is for you. This tutorial shows you how to create a solution with Twilio Programmable Voice and a SIP softphone software or an SIP IP Phone that enables employees to work from their homes.

    Configure the Programmable Voice SIP Endpoint

    You can forward incoming calls to Twilio numbers registered to SIP endpoints, and use a free softphone as an endpoint while working from home, as shown below:

    Flow for how employees can work from home using Twilio

    To get started with the project you will need the following:

    • A Twilio account. Sign up for a free trial account and get a $10 credit.
    • A call-enabled Twilio Phone Number.
    • SIP endpoint (IP Phones (e.g. Obihai) or Softphones (e.g. Zoiper or X-Lite)).

    Create the application

    Go to twilio.com and sign up for a free account or log in to your existing account. …

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  • By Jonas Lerebours
    Incident Notification and Escalation Loop using Programmable Voice Incident Notification and Escalation Loop

    Systems and Infrastructures are constantly monitored, and monitoring teams need to dispatch technicians to fix issues as fast as possible when an incident is raised. Using the Twilio API you already can call a single number to reach a technician and deliver a message, or call several numbers and deliver the message to the first person who answers. In this article we introduce an escalation loop: define several people to be called in case of an incident and call them in order, one after the other, until one of them accepts the call.

    For this to happen, we created a reusable set of Twilio Functions that can be triggered by a simple call to a REST API. The code for this solution is available on Github and can be easily deployed on your Twilio project.


    Before you can build the escalation and notification loop, you'll need to register or …

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  • By Ashley Boucher
    Verify a User via Phone with Twilio Functions and Twilio Verify verifyvoice.png

    Many applications verify and authorize their users by sending a numeric code, called a One-Time Passcode (OTP), to the user’s phone number via either a voice call or a text message.

    In this article you’ll learn how to perform user verification via a phone call through Twilio Verify. You’ll build a pared down frontend using JavaScript and HTML and you’ll build a Node.js backend, all hosted with Twilio Functions, which will be scaffolded using the Twilio Serverless Toolkit, a plugin for the Twilio CLI.


    To get started with this tutorial, you’ll need the following:

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  • By Brooke Isaacs
    Understanding SIP Trunk and SIP Lines SIPTrunk_SIPLine.png

    Though there are many innovative ways to market to your customers via SMS and email, phone calls are still as important as ever to an organization’s communication strategy. It’s easy to stick to the traditional phone line status quo, but to do so is to ignore the opportunity to save money and take advantage of an affordable, scalable system on the cloud.

    SIP trunk phone systems offer an opportunity to increase your efficiency while cutting the costs of a traditional, physical phone line system. Taking place entirely on the cloud, SIP systems enable an existing phone system to function online by routing calls via an on-premise private branch exchange (PBX) through a SIP line connected to an organization’s SIP trunk and then out to its intended recipient.

    Whether you’re looking to make the switch to an entirely online SIP phone system or are just looking for some clarification of the …

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  • By Josh Siverson
    Voice Architecture and Best Practices for Independent Software Vendors (ISVs) ISV_voice_header


    Twilio is a trusted provider in the telecommunications industry, helping customers navigate the complexities of the ever-changing communications ecosystem. Twilio partners with a wide variety of Independent Software Vendors (ISVs) that leverage Twilio technology to build robust, scalable, and innovative communication infrastructures. ISVs serve hundreds, if not thousands of customers - building elegant and scalable platform architecture to support these customers is critical. In this blog post, we aim to provide ISV product managers, architects and developers with the design principles, product knowledge, and best practices needed to launch a successful ISV voice solution. At the end of this blog post, you should be equipped to start implementation on a voice enabled product specifically designed with your customer’s needs in mind.

    Challenges for ISVs

    Voice connectivity and call orchestration can be complex - ISVs need to provide reliable, easy to integrate, and flexible voice solutions to customers. ISVs should …

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  • By Miguel Grinberg
    Make a Phone Call with a Duration Limit Using Python and Twilio Programmable Voice Make a Phone Call with a Duration Limit Using Python and Twilio Programmable Voice

    Twilio Programmable Voice allows you to make programmatic voice calls directly from your application. This service was recently expanded to support a call duration limit, which can be a useful way to avoid unexpected expenses from calls that remain connected for a long time.

    In this tutorial, you’ll learn how to use Programmable Voice with Python to make a voice call with a predefined maximum duration.


    Setting up your environment

    In this section, you …

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  • By Dhruv Patel
    How to Send Voice-to-SMS Transcripts Using Twilio Voice and Programmable SMS Header


    SMS and audio transcripts can be a great way to perpetuate communication without needing to pick up the phone unexpectedly. Twilio streamlines this process through the Voice API using Twilio’s Markup Language, TwiML, which processes incoming calls accordingly.

    TwiML offers the <Record> verb, which records the caller's voice and can automatically generate text transcriptions sent right to your phone. For those that are always on the go or can’t be bothered to check their voicemail inbox, you’ll never miss a message again. In this tutorial, you will learn how to leverage Twilio’s Voice API and Programmable SMS to transcribe voice calls into text messages.


    Project setup

    In this section, you are …

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