AutoForge: Automated Environment Synthesis for Agentic Reinforcement Learning

Shihao Cai, Runnan Fang, Jialong Wu, Baixuan Li, Xinyu Wang, Yong Jiang, Liangcai Su, Liwen Zhang, Wenbiao Yin, Zhen Zhang, Pengjun Xie, Xiaobin Wang, Fuli Feng


Abstract
Conducting reinforcement learning (RL) in simulated environments offers a cost-effective and highly scalable way to enhance language-based agents. However, previous work has been limited to semi-automated environment synthesis or tasks lacking sufficient difficulty, offering little breadth or depth. In addition, the instability of simulated users integrated into these environments, along with the heterogeneity across simulated environments, poses further challenges for agentic RL. In this work, we propose: (1) a unified pipeline for automated and scalable synthesis of simulated environments associated with high-difficulty but easily verifiable tasks; and (2) a multi-environment user-centric RL algorithm that not only effectively mitigates user instability but also performs advantage estimation at the environment level, thereby improving training efficiency and stability. Comprehensive evaluations on agentic benchmarks, including 𝜏-bench, 𝜏2-Bench, and VitaBench, validate the effectiveness of our proposed method. Further in-depth analyses underscore its out-of-domain generalization.
Anthology ID:
2026.emnlp-main.837
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
19422–19433
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URL:
https://aclanthology.org/2026.emnlp-main.837/
DOI:
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Cite (ACL):
Shihao Cai, Runnan Fang, Jialong Wu, Baixuan Li, Xinyu Wang, Yong Jiang, Liangcai Su, Liwen Zhang, Wenbiao Yin, Zhen Zhang, Pengjun Xie, Xiaobin Wang, and Fuli Feng. 2026. AutoForge: Automated Environment Synthesis for Agentic Reinforcement Learning. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 19422–19433, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
AutoForge: Automated Environment Synthesis for Agentic Reinforcement Learning (Cai et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.837.pdf