Researchers have discovered that code, the language used to write software, is no longer just a tool for creating programs, but is becoming a key component of artificial intelligence systems. In these new systems, code is used to create a kind of "framework" that allows the AI to understand its environment, make decisions, and take actions. This framework, called a "code harness," is being developed to make AI systems more reliable, adaptable, and scalable. The researchers are exploring how to design and use code harnesses to create more sophisticated AI systems that can work together and be verified, and they're also identifying challenges to overcome in order to make these systems a reality.