VIKI-R: Coordinating Embodied Multi-Agent Cooperation via Reinforcement
  Learning
Authors: name: Li Kang, name: Xiufeng Song, name: Heng Zhou, name: Yiran Qin, name: Jie Yang, name: Xiaohong Liu, name: Philip Torr, name: Lei Bai, name: Zhenfei Yin

Coordinating multiple embodied agents in dynamic environments remains a core
challenge in artificial intelligence, requiring both perception-driven
reasoning and scalable cooperation strategies. While recent works have
leveraged large language models (LLMs) for multi-agent planning, a few have
begun to explore vision-language models (VLMs) for visual reasoning. However,
these VLM-based approaches remain limited in their support for diverse
embodiment types. In this work, we introduce VIKI-Bench, the first hierarchical
benchmark tailored for embodied multi-agent cooperation, featuring three
structured levels: agent activation, task planning, and trajectory perception.
VIKI-Bench includes diverse robot embodiments, multi-view visual observations,
and structured supervision signals to evaluate reasoning grounded in visual
inputs. To demonstrate the utility of VIKI-Bench, we propose VIKI-R, a
two-stage framework that fine-tunes a pretrained vision-language model (VLM)
using Chain-of-Thought annotated demonstrations, followed by reinforcement
learning under multi-level reward signals. Our extensive experiments show that
VIKI-R significantly outperforms baselines method across all task levels.
Furthermore, we show that reinforcement learning enables the emergence of
compositional cooperation patterns among heterogeneous agents. Together,
VIKI-Bench and VIKI-R offer a unified testbed and method for advancing
multi-agent, visual-driven cooperation in embodied AI systems.