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, Fuli Feng, Pengjun Xie, Xiaobin Wang
TL;DR
AutoForge tackles the cost, fragility, and limited breadth of agentic RL by coupling an automated, scalable synthesis of interactive environments with Environment-level Relative Policy Optimization (ERPO). The pipeline automatically constructs environments from tool descriptions, generates complex tool-sequences within a DAG framework, and creates verifiable tasks, while masking erroneous user behavior and estimating advantages at the environment level to boost stability. Empirical results on tau-bench, tau2-Bench, VitaBench, and ACEBench-zh show strong in-domain performance gains and notable out-of-domain generalization, with RL-based variants benefiting most from the synthetic environments. This work demonstrates that automated mock environments can substantially advance scalable, robust agentic learning and generalization to unseen tasks.
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) an environment level 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 tau-bench, tau2-Bench, and VitaBench, validate the effectiveness of our proposed method. Further in-depth analyses underscore its out-of-domain generalization.
