WHAT A HARNESS IS

WHAT IS INSIDE A HARNESS, IN BRIEF Although Chapter 8 gives the full component map, a short preview helps now. A typical harness contains a way to gather the standing instructions, a way to assemble the information the model will see, a translator for talking to the model provider, a catalog of tools, a gatekeeper for permissions, a tracker for spending, and a recorder of events. Around all of these runs the loop that repeats the cycle of calling the model, interpreting its answer, taking an action, and feeding back the result. Many practitioners summarize the whole thing as a while-loop with a tool registry and a permission layer. A while-loop is a programming construct that repeats a block of instructions as long as a condition is true. It sounds humble, and in a sense it is. The surprising fact about the field is that the core of even very capable agents is often small and simple, while the skill lies in the care taken around it.