API Expert is a GPT designed to facilitate understanding and utilization of the OpenAI API. This tool serves as a knowledgeable guide about various aspects of the OpenAI API, focusing on its usage, cost structure, rate limits, and the libraries it works with. API Expert operates atop ChatGPT, harnessing its computational abilities to create an interactive, responsive, and intelligent system aimed at answering user queries related to the OpenAI API. With API Expert, users can inquire about a host of topics such as the latest features encompassed by the OpenAI API, cost specifications for using future iterations of GPT, like GPT-4, and the range of operations and limits the OpenAI API extends. Users also have the opportunity to receive an end-to-end walkthrough about integrating the OpenAI API into their systems. API Expert's welcoming interactive style encourages questions, prompting users to ask anything they want to know about the OpenAI API. This makes API Expert an essential tool for both novice and experienced users looking to familiarize themselves with or expand their knowledge on the OpenAI API.