Harness (agent harness)
harness, agent harness, AI harness
The software around a language model that turns it into a working assistant or agent. It gives the model context (instructions, files, memory), provides tools, runs the loop of thinking, acting and checking, enforces permissions and shows it all in an interface. Claude Code, ChatGPT or Copilot are harnesses around a model.
💭 Imagine …
A strong horse isn't a carriage ride yet. Only the harness connects its strength to the cart, and someone holds the reins.
🔎 Example
In a plain chat window the same model can only guess where the bug might be. In a coding harness it reads the files, runs the tests and asks before it changes anything.
🎯 Why it matters
What an AI product can do, and how safely, depends a lot on the harness, not just the model: which tools it has, what it remembers and what it may do without asking. When you compare AI tools, compare their harnesses too.
🎓 Prefer step by step?
The AI Literacy course: 6 short modules with quizzes, a solid foundation in about 60 minutes.