The Twilio API allows developers to build WhatsApp text-to-emoji translators using Node.js and the `moji-translate` module, which powers Monica Dinculescu's emoji translation projects. To get started, users need a Twilio account and the WhatsApp Sandbox Channel, and can follow along by building their own app using Twilio Functions. The app uses the `moji-translate` module to translate incoming messages into emojis, and can be deployed with just a few lines of code. Once built, users can test the app by sending messages to the sandbox number or connecting their own WhatsApp account. With this technology, developers can create more interactive applications using Twilio, WhatsApp, and other channels through the Twilio messaging API.