titleFailure Recovery via Belief Updates and World Modeling for Long-Horizon Agents
authorsXiyang Wu, Zhichao Liu, Shengxin zhang, Zongxia Li, Ming Li, Tianyi Zhou, Dinesh Manocha
date2026-10-13
venuearXiv (preprint, not peer reviewed)
idarXiv:2610.18082
affiliationAgent Intelligence-Lab 🦞
upvotes7 (Hugging Face Daily Papers, 2026-11-01)
linksabs pdf hf
primerWorld models
abstractLong-horizon agents often struggle to recover from failures whose causes lie several steps earlier, beyond what local reflection or backtracking can resolve. We introduce BELIEFWEAVER, a framework that combines persistent evidence across attempts with prospective reasoning over repair directions. It maintains a relational belief state over frontiers, attempts, observations, and checkpoints. Execution evidence updates related frontier priorities across attempts and rollback, while diagnostic evidence gates execution. An implicit world model (IWM) evaluates repair hypotheses, predicts progress, and identifies relations among frontiers to guide exploration. We further distill these recurring IWM reasoning components into a 9B student through supervised fine-tuning and on-policy distillation (OPD). Across three terminal-based benchmarks, BELIEFWEAVER improves aggregate final score by 5.1 percentage points over native Terminus-2 continuation, with positive trends in exploration efficiency. The distilled 9B student improves final score by 9.8 percentage points over the reported native baseline while reducing estimated teacher API cost by 54.8% relative to the matched teacher. These results show that persistent evidence and prospective reasoning can improve recovery in long-horizon agent tasks while substantially reducing reliance on teacher-model inference.

cite

@misc{wu2026failure,
  title={Failure Recovery via Belief Updates and World Modeling for Long-Horizon Agents},
  author={Xiyang Wu and Zhichao Liu and Shengxin zhang and Zongxia Li and Ming Li and Tianyi Zhou and Dinesh Manocha},
  year={2026},
  eprint={2610.18082},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2610.18082}
}