Harness-S rescues failed RL rollouts with sibling harnesses for generalizable agents

SJUT1 · hf · 2026-11-06

A paper from SJTU, Xiaohongshu, CMU and others introduces Harness-S, a selective harness-rescue training method. Sibling harness variants from a common base exhibit locality, complementarity, and nonstationarity; the pool is invoked only when all attempts under the base harness fail, replacing failed RL rollout groups with trajectories regenerated under selected auxiliary harnesses. An adaptive router picks Top-k variants via behavior profiles and multi-LLM voting. Across AppWorld, SWE-Gym, and DBBench, the trained policy substantially outperforms policy-only training under the base harness, and reusing the router for Rank-1 inference adds gains at the same rollout count.

Original post →

More from coding & agent

coding & agent channel →