VibeArena: Self-Evolving Executable Worlds for Embodied Agents

We present VibeArena, which builds executable 3D worlds in code and improves construction knowledge and agent harness policies using construction and execution experience. The challenge is to reuse successful builds and repairs while preserving relations between object mechanisms and spatial context. Therefore, VibeArena links scene layout, object geometry, articulation, physical properties, and tasks in a shared world program that coordinates multiple agents. Hierarchical intermediate representations carry interaction constraints into code-based object generation, while execution feedback directs targeted revisions to structures that determine task feasibility. Validated builds provide templates, accepted repairs provide conditional rules, and their histories refine inspection and repair scheduling. Self-evolution consolidates construction experience into reusable templates, conditional rules, and scheduling policies, with rules and policies validated across scenes and refined or retired as evidence accumulates. Experiments demonstrate leading performance in object and scene generation quality, physical stability, and downstream tasks, with visual examples of diverse scenes and detailed articulated assets. VibeArena uses lessons from building and testing worlds to improve how it constructs later worlds.