AutoWorldModel-Bench: A State-Centric Benchmark for Automated World-Model Research

[Submitted on 20 Jul 2026]

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Abstract:World modeling is an unsettled field: architectures, training objectives, and state representations interact in complex ways, and no single recipe dominates across environments. This makes it an ideal testbed for AI coding agents acting as autonomous researchers–a setting in which the improvement direction is not specified in advance, unlike the engineering-to-spec tasks that dominate current agent benchmarks. We introduce AutoWorldModel-Bench, a closed-loop benchmark in which frontier coding agents autonomously improve a provided world-model starter under a fixed compute budget. The benchmark spans eight game environments under a unified structured-state representation–ground-truth entity state extracted from each game and consumed through a shared tensor format–which isolates dynamics modeling from perception and enables minutes-per-run iteration. Across 64 sessions, Codex-5.4 and Claude Opus 4.6 improve their starter on 63; in 91% of sessions the winning edit is a non-trivial research-style modification–a new objective, representation, rollout procedure, or architectural change–rather than a hyperparameter tweak. Our benchmark offers a setting in which frontier coding agents can be evaluated on open-ended research rather than engineering-to-spec problems.

Submission history

From: Marjan Moodi [view email]
[v1] Mon, 20 Jul 2026 23:35:45 UTC (851 KB)