Ex-ChatGPT is a Python-based service that enhances ChatGPT by enabling it to call external APIs for more accurate and timely answers. It combines GPT-3.5 Turbo with tools like WolframAlpha, Google Search, and WikiMedia through a web interface. The project includes a browser extension (WebChatGPTEnhance) and features OAuth2.0 multi-user authentication, voice dialogue using Azure API, token usage tracking, and markdown rendering with MathJax support.