GoKawiilGoogle Research releases Harness² framework for self-improving AI agent systems
Google Research has released Harness², an open-source framework that lets AI agents refine their own operating 'harness'—prompts, tools, memory and workflow—without changing the underlying model's weights. The system works through two feedback loops: one that tweaks the harness for the task at hand by comparing different execution attempts, and another that keeps a persistent record of lessons learned to guide future tasks. Tests on GLM-5 and Gemini 3.5 Flash showed performance gains of up to 11.5 points on one benchmark and 11.8 percentage points on another after a single refinement step.