CoopAgent: Training Multi-Agent Cooperation from Single-Agent Execution Trajectories

Zhengzhe Pan, Linchao Zhu, Yi Yang


Abstract
LLM-based multi-agent systems have demonstrated strong potential for solving complex tasks, yet reliable collaboration remains challenging. While most training-based methods rely on multi-agent trajectories, we investigate whether cooperative behaviors can be strengthened using only single-agent execution data. We propose CoopAgent, a training framework that learns solely from single-agent execution trajectories and transfers to multi-agent deployment. To bridge the gap between single-agent training and multi-agent environments, we introduce PADPO (Perturbation-Aligned DPO), which aligns action preferences between original observations and task-related perturbations that mimic changes caused by other agents. We train CoopAgent on single-agent execution trajectories collected in Minecraft and evaluate it on VillagerBench. The results demonstrate its potential to enhance collaboration on VillagerBench while preserving strong single-agent execution ability. We further assess CoopAgent on out-of-domain benchmarks, showing improvements in several multi-agent settings and performance comparable to the multi-agent training method AT-GRPO on the coding benchmarks. Our code is available at https://github.com/hlpzz/CoopAgent.
Anthology ID:
2026.findings-emnlp.892
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:
18891–18909
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.892/
DOI:
10.18653/2026.findings-emnlp.892
Bibkey:
Cite (ACL):
Zhengzhe Pan, Linchao Zhu, and Yi Yang. 2026. CoopAgent: Training Multi-Agent Cooperation from Single-Agent Execution Trajectories. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 18891–18909, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
CoopAgent: Training Multi-Agent Cooperation from Single-Agent Execution Trajectories (Pan et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.892.pdf