Harnesses in AI: A Deep Dive @TejasKumar_ builds a browser agent on GPT-3.5 Turbo that has one job: upvote a post on Hacker News. Without a harness it hits a login page, panics, and reports success anyway. The upvote never happened. https://youtube.com/watch?v=C_GG5g38vLU He fixes it without touching the prompt once. Guardrails cap the iteration count and compact context when it bloats. A verify step reads the actual tool call history to catch the lie. A login handler watches the…