AI harness

The scaffolding wrapped around an AI model that turns it into something able to do real work. A model on its own just predicts the next piece of text. The harness is everything around it: the tools it can call, the loop that lets it take an action and check the result before acting again, the memory and context it works from, and the guardrails and permissions that limit what it can touch. Think of the model as the engine and the harness as the rest of the car. This matters for safety, because the limits on what an agent is allowed to do often live in the harness, not in the model itself. The word is also used in AI evaluation to mean a test harness, the standardized setup for running a model through benchmarks, but in agentic AI it means the orchestration layer described here.

Terms like this come up in real clinical scenarios across the HelloAI courses: bite-sized modules with verifiable certificates. An account takes one minute, no password needed.