In this tutorial, learn how to build an AI voice assistant using Twilio Voice and the OpenAI Realtime API, powered by Node.js. The OpenAI Realtime API unlocks fluid conversations that feel like real human dialog. To follow along with this tutorial, you will need Node.js 18+, a Twilio account, a Twilio number with Voice capabilities, an OpenAI account and API Key, access to the OpenAI Realtime API, and optionally ngrok or another tunneling solution. The assistant can be used for various tasks such as answering questions or telling jokes.