Build an agent harness from scratch to pass Ian Goodfellow's intelligence test (notesbylex.com)

In 2026, the development and research around building agent harnesses has surged, with many AI professionals now focused on creating these systems for various applications. A recent article outlines a method for constructing a modern agent harness from scratch, specifically designed to meet the challenge posed by Ian Goodfellow regarding the demonstration of "real AI." The article details a fundamental loop structure of the harness that integrates a large language model (LLM) and tools, emphasizing the importance of context management and safety checks. This exploration into agent harnesses is significant for the AI/ML community as it showcases a practical approach to developing intelligent systems capable of automating programming tasks through coding harnesses. The tutorial offers insights into leveraging LLMs within these harness architectures while addressing crucial design aspects such as tool management, safety controls, and user extension possibilities. By drawing from existing frameworks and incorporating lessons learned from recent research, the article provides a hands-on guide that equips developers with the foundational skills needed to create effective, adaptable agent harnesses, further propelling advancements in AI capabilities and applications.