LiveKit, developer of infrastructure software for real-time AI voice and video applications announcement A $100 million increase in funding at a $1 billion valuation.

Round, which comes ten months after LiveKit Previous FundraisingIndex Ventures was led with participation from existing investors including Altimeter Capital Management, Hanabi Capital and Redpoint Ventures.

LiveKit powers OpenAI’s ChatGPT voice mode. The startup’s other customers include xAI, Salesforce, Tesla, as well as 911 emergency service operators and mental health providers.

The company was founded in 2021 by Russ d’Sa and David Zhao as an open-source software project to create apps that can transmit real-time audio and video without interruption, in an era when the entire world was adapting to Zoom during the pandemic.

Although LiveKit began as a free developer tool, the founders realized that large companies wanted a managed cloud version, and the business took off after they began providing those services to enterprises amid the voice AI boom.