This article details how the author successfully ported the JustHTML project from Python to JavaScript in just a few hours using OpenAI’s Codex CLI and GPT-5.2 model. As an intriguing project demonstrating the concept of ‘ambient engineering,’ JustHTML’s rapid cross-language migration showcases the powerful capabilities of AI-assisted programming. The article provides a detailed account of the code conversion process using AI tools, the challenges encountered, and their solutions, offering developers a practical case study in AI-assisted programming. Additionally, it explores how recent enhancements in OpenAI’s ChatGPT and Codex CLI have further improved the efficiency and practicality of AI-assisted development. This case study not only demonstrates the potential of AI technology in software development but also provides developers with new approaches to leveraging AI tools for enhanced productivity.