Asif Razzaq writes that Google Research has open-sourced Harness², a framework that improves agent performance by recursively refining the surrounding harness—prompts, tools, memory, and orchestration—while keeping model weights frozen. It operates without ground-truth labels, using a Propose, Probe, Compose cycle to test candidate harness edits against observed behavior.
- Weaker executors gained more; GLM-5 beat base Gemini 3.5 Flash on WorkBuddy-Bench after one refinement step
- Parallel recursion at k=5 lifted Gemini under OpenCode to 80.8 on WorkBuddy
- The framework extends the 7-file split from earlier Agentic Harness Engineering work by 1 component
- Requires Linux, Python 3.12+, uv, and Vertex AI for model-backed runs
- Weaker executors gained more; GLM-5 beat base Gemini 3.5 Flash on WorkBuddy-Bench after one refinement step
- Parallel recursion at k=5 lifted Gemini under OpenCode to 80.8 on WorkBuddy
- The framework extends the 7-file split from earlier Agentic Harness Engineering work by 1 component
- Requires Linux, Python 3.12+, uv, and Vertex AI for model-backed runs
