With the Twilio API for WhatsApp we can send messages to WhatsApp numbers. Those messages can be plain text or include files like images, audio and even PDFs up to 5MB. Let's see how to do so using Ruby.

Things you'll need

If you want to code along with this post, you'll need a few things:

• A Twilio account (sign up for a free account now)
• Ruby and Bundler installed
• The WhatsApp Sandbox Channel installed (learn how to activate your WhatsApp sandbox)

Got all that? Let's get coding then!

Create a new directory for your project and use Bundler to initialise a new Gemfile:

Open up the new Gemfile and add the twilio-ruby gem:

Install the gem by running bundle install on the command line.

Sending your first WhatsApp message

Create a file in your project ...

If you're building a Twilio project you will inevitably need to run some code in response to an incoming webhook request. One of the easiest ways to do this is with Twilio Functions, our serverless platform for running Node.js. Recently my colleague Dominik released the twilio-run package that makes it easier to develop, test and debug Twilio Functions locally.

I wanted to make it even easier to get started with a Twilio Functions project, so I built a project generator called create-twilio-function.

Let's take a look at how you can easily start and develop a Twilio Functions project using create-twilio-function and twilio-run.

Getting started

There are a few ways you can use create-twilio-function. The easiest is if you have npm version 6 or higher. You can check this out on the command line with:

If you don't have an up to date version of ...

Did you know you can send and receive media using the Twilio API for WhatsApp? When I found out I wanted to make something fun with it, so why not combine it with AWS Rekognition to work out if I look like any celebrities?

By the end of this post, you'll know how to build an app that lets you send an image to a WhatsApp number, download the image, analyse the image with the AWS Rekognition API and respond to say whether there are any celebrities in the picture.

What you'll need

To build this application you'll need a few things:

• A Twilio account, sign up for a free one here
• An AWS account
• Ruby and Bundler installed
• ngrok to help us test our webhooks

Got all that? Let's get started then.

Application basics

When Twilio receives a WhatsApp message it will send an HTTP request, a webhook, to ...

Have you ever needed to download and save an image in your Ruby application? Read on to find out how.

Plain old Ruby

The most popular way to download a file without any dependencies is to use the standard library open-uri.

Kernel#open is a method that you can use to open files, streams, or processes to read to or write from. For example, you can open a file and read its contents with the following code:

open-uri extends Kernel#open so that it can open URIs as if they were files. We can use this to download an image and then save it as a file.

To do so, we first require open-uri then use the open method to access an image URL. We can then open up a file and write the contents of the image to the file ...

Twilio Programmable Chat provides an SDK and robust back-end for real time chat applications, but it's missing a front-end. If you need a chat UI, as well as a whole bunch of other useful components, then KendoReact might be what you're looking for.

Kendo UI provides well designed and tested components that you can use within your React, Angular, Vue and jQuery applications. In this post we will build a Twilio Chat application with React and the KendoReact conversational UI components.

What you'll need

If you want to build along with this tutorial, then you'll need a few things:

• A Twilio account (you can sign up for a Twilio account for free here)
• A Twilio Chat service and an API key and secret, both of which you can create in the Twilio console (keep these nearby, you'll need them soon)
• Node.js to build our React app and to run ...

It's 2019 and you need to receive a fax. What do you do? You could buy a fax machine, hook it up to a phone line and hand out your number. But it's 2019 not 1979, we're living in the future, so let's grab Node.js, pick a couple of APIs and turn that fax into an email instead.

You're going to need a Twilio account, a SendGrid account and this noise to remind you what you're missing out on as you build your very own fax-to-email converter.

Receiving a fax

Rather than bulky machinery we're going to use a Twilio number to receive our incoming faxes. You're going to need a Twilio number that supports fax to build this app, so log in to your Twilio account. You can buy a new number or you may already have one, just look for this icon to show that it can ...

We talk a lot about sending SMS messages from web applications, but what about sending SMS messages from a React application? There's a bit more to it than just the server-side version, but it won't take us long.

Why shouldn't I use the REST API from the client-side?

Technically you could send an SMS using the Twilio REST API directly from a JavaScript client-side application. But (and it's a very big "but") if you were to do that, you would expose your Twilio credentials to anyone using your site. A malicious user could then take those credentials and abuse them, running up a huge bill with your account.

Live view of a hacker with your account credentials

To avoid this we will create a back end application that implements the Twilio REST API, wraps up your credentials and sends SMS messages for you. Then you can call your back end ...

Create React App is a great tool for getting a React application up and running. It's a little less clear when you're building or prototyping an application that requires a server side component, like generating access tokens for Twilio Video or Chat, though. I've found it easiest to work with a server within the same project so that you can start everything up with one command.

By the end of this post you will learn how to set up an Express server that runs alongside a React app. If you can't wait then you can jump straight into the starter project on GitHub.

How it works

There is an option that you can set in Create React App's package.json that proxies non text/html requests through to an alternative back end. You can use this feature to proxy to applications running elsewhere, but today we want to be ...

The Web Audio API is a powerful browser API for creating, manipulating and analysing audio. I'm no musician, so I'll leave the creating and manipulating to the experts. Instead, in this post we're going look at analysing audio. To make things extra interesting, we're going to see how to visualise the audio in a React component with <canvas>.

When we're done we'll have a React application that can listen to the microphone on your computer and show a waveform to visualise the data.

Getting started

We'll need Node.js to run the application, so make sure you have it installed. I've started the application for us, so follow these instructions to get it running:

1. Clone or download the repo from GitHub

1. Change into the directory and install the dependencies with npm

1. Start the application