Vapi is a voice AI platform that aims to make interactions feel warmer and human via audio, similar to chatting with a friend. It's designed for developers to build voice AI applications without worrying about the underlying tech. Vapi acts as an orchestration layer over Speech-to-Text, Large Language Model, and Text-to-Speech providers, allowing users to bring their own models, custom voices, and manage conversational dynamics. The platform is built to solve foundation challenges in voice AI applications, such as simulating natural human conversation and taking actions, with a focus on reliability, accessibility, and low latency. Users can create their own Vapi instances by adding prompts, picking models and voices, and deploying them behind phone numbers or APIs.