{"slug": "what-is-an-agentic-harness-actually", "title": "What is an \"agentic harness,\" actually?", "summary": "A developer explores the concept of an 'agentic harness' in LLM-based agents, clarifying that it is not the user-facing application but the underlying decision-making infrastructure that determines when an agent continues or stops. The insight comes from a discussion with developer greggyb, who explained the distinction between the LLM, the agent, and the harness.", "body_md": "I've been hearing the word \"harness\" thrown around a lot lately. I assumed it just meant *\"the IDE\"* or *\"whatever app is running your agent.\"* Turns out, it goes a little deeper than that.\n\nSo I sat down with [@greggyb](https://dev.to/greggyb) and asked him to explain it from the ground up: what an LLM actually does, what turns it into an agent, and where the harness fits into all of it.\n\nThe point that stuck with me is the harness isn't the app you're looking at. It's the invisible plumbing deciding whether the agent keeps going or calls it done.\n\nDid your mental model of \"harness\" match up? Or were you picturing something else too?", "url": "https://wpnews.pro/news/what-is-an-agentic-harness-actually", "canonical_source": "https://dev.to/googleai/what-is-an-agentic-harness-actually-4oie", "published_at": "2026-07-16 21:19:20+00:00", "updated_at": "2026-07-16 21:36:07.678793+00:00", "lang": "en", "topics": ["artificial-intelligence", "large-language-models", "ai-agents"], "entities": ["greggyb"], "alternates": {"html": "https://wpnews.pro/news/what-is-an-agentic-harness-actually", "markdown": "https://wpnews.pro/news/what-is-an-agentic-harness-actually.md", "text": "https://wpnews.pro/news/what-is-an-agentic-harness-actually.txt", "jsonld": "https://wpnews.pro/news/what-is-an-agentic-harness-actually.jsonld"}}