Is the Agent Harness Dead? — Jediah Katz, SpaceXAI

Is the agent harness dead? Jediah Katz (SpaceXAI, formerly Cursor’s longest-tenured agent-harness engineer) explains what smarter models mean for coding agents, Grokbot and the future of agent harnesses. He shows why fancy harnesses no longer add coding intelligence: the data flywheel teaches models the skills harnesses used to patch in. Then he argues the harness matters more than ever. It opens new frontiers like Grokbot, and it owns what models can’t absorb: infrastructure, trust and security, and efficiency. He closes with predictions for AI agents, including that 90% of agent work runs o