OffSeeker: Online Reinforcement Learning Is Not All You Need for Deep Research Agents
Yuhang Zhou, Kai Zheng, Qiguang Chen, Mengkang Hu, Qingfeng Sun, Can Xu, Jingjing Chen
TL;DR
This work challenges the prevailing assumption that online reinforcement learning is essential for high-performance deep research agents by showing that a carefully designed offline training pipeline can achieve competitive results. It introduces DeepForge, an open-source framework that synthesizes large-scale, multi-hop deep research tasks without heavy preprocessing, and releases a substantial resource suite (66k QA pairs, 33k SFT trajectories, 21k DPO pairs). The OffSeeker 8B model, trained entirely offline via SFT and Direct Preference Optimization, demonstrates strong performance across six benchmarks, matching or approaching 30B-parameter online-RL systems while drastically reducing API costs and improving reproducibility. Together, these contributions advance accessible, cost-effective development of deep research agents and open avenues for broader academic participation in this area.
Abstract
Deep research agents have shown remarkable potential in handling long-horizon tasks. However, state-of-the-art performance typically relies on online reinforcement learning (RL), which is financially expensive due to extensive API calls. While offline training offers a more efficient alternative, its progress is hindered by the scarcity of high-quality research trajectories. In this paper, we demonstrate that expensive online reinforcement learning is not all you need to build powerful research agents. To bridge this gap, we introduce a fully open-source suite designed for effective offline training. Our core contributions include DeepForge, a ready-to-use task synthesis framework that generates large-scale research queries without heavy preprocessing; and a curated collection of 66k QA pairs, 33k SFT trajectories, and 21k DPO pairs. Leveraging these resources, we train OffSeeker (8B), a model developed entirely offline. Extensive evaluations across six benchmarks show that OffSeeker not only leads among similar-sized agents but also remains competitive with 30B-parameter systems trained via heavy online RL.
