AgentSwing: Adaptive Parallel Context Management Routing for Long-Horizon Web Agents

Zhaopeng Feng, Liangcai Su, Zhen Zhang, Xinyu Wang, Xiaobin Wang, Runnan Fang, Xiaotian Zhang, Hui Chen, Qi Zhang, Joey Tianyi Zhou, Pengjun Xie, Chenxiong Qian, Bryan Hooi, Zuozhu Liu


Abstract
As large language models (LLMs) evolve into autonomous agents for long-horizon information-seeking, managing finite context capacity has become a critical bottleneck. Existing context management methods typically commit to a single fixed strategy throughout the entire trajectory. Such static designs may work well in some states, but they cannot adapt as the usefulness and reliability of the accumulated context evolve during long-horizon search. To formalize this challenge, we introduce a probabilistic framework that characterizes long-horizon success through two complementary dimensions: search efficiency and terminal precision. Building on this perspective, we propose AgentSwing, a state-aware adaptive parallel context management routing framework. At each trigger point, AgentSwing expands multiple context-managed branches in parallel and uses lookahead routing to select the most promising continuation. Experiments across diverse benchmarks and agent backbones show that AgentSwing consistently outperforms strong static context management methods, often matching or exceeding their performance with substantially fewer interaction turns while also improving the ultimate performance ceiling of long-horizon web agents. Beyond the empirical gains, the proposed probabilistic framework provides a principled lens for analyzing and designing future context management strategies for long-horizon agents.
Anthology ID:
2026.findings-emnlp.750
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
15789–15808
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.750/
DOI:
Bibkey:
Cite (ACL):
Zhaopeng Feng, Liangcai Su, Zhen Zhang, Xinyu Wang, Xiaobin Wang, Runnan Fang, Xiaotian Zhang, Hui Chen, Qi Zhang, Joey Tianyi Zhou, Pengjun Xie, Chenxiong Qian, Bryan Hooi, and Zuozhu Liu. 2026. AgentSwing: Adaptive Parallel Context Management Routing for Long-Horizon Web Agents. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 15789–15808, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
AgentSwing: Adaptive Parallel Context Management Routing for Long-Horizon Web Agents (Feng et al., Findings 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.findings-emnlp.750.pdf