Code World Models for Parameter Control in Evolutionary Algorithms
On the map: World models → World models for language agents
Abstract (arXiv)
Can an LLM learn how an optimizer behaves -- and use that knowledge to control it? We extend Code World Models (CWMs), LLM-synthesized Python programs that predict environment dynamics, from deterministic games to stochastic combinatorial optimization. Given suboptimal trajectories of (1+1)-RLSk, the LLM synthesizes a simulator of the optimizer's dynamics; greedy planning over this simulator then selects the mutation strength k at each step. On lo and onemax, CWM-greedy performs within 6% of the theoretically optimal policy -- without ever seeing optimal-policy trajectories. On jumpk, where a deceptive valley causes all adaptive baselines to fail (0% success rate), CWM-greedy achieves 100% success rate -- without any collection policy using oracle knowledge of the gap parameter. On the NK-Landscape, where no closed-form model exists, CWM-greedy outperforms all baselines across fifteen independently generated instances (36.94 vs. 36.32; p<0.001) when the prompt includes empirical transition statistics. The CWM also outperforms DQN in sample efficiency (200 offline trajectories vs. 500 online episodes), success rate (100% vs. 58%), and generalization (k=3: 78% vs. 0%). Robustness experiments confirm stable synthesis across 5 independent runs.
Key facts. No citing papers in the map yet (data through 7 Oct 2026). Placed in World models for language agents, one of 11 directions in World models. Builds on 9 of its 24 references that are in the map. First posted on arXiv 25 Feb 2026.
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- 2018World Modelscited by 1,444
- 2019Mastering Atari, Go, Chess and Shogi by Planning with a Learned Modelcited by 1,327
- 2025Mathematical exploration and discovery at scalecited by 66
- 2019Deep Reinforcement Learning Based Parameter Control in Differential Evolutioncited by 37
- 2017Fast Genetic Algorithmscited by 29
- 2019Self-Adjusting Mutation Rates with Provably Optimal Success Rulescited by 13
- 2018On the Effectiveness of Simple Success-Based Parameter Selection Mechanisms for Two Classical Discrete Black-Box Optimization Benchmark Problemscited by 1
- 2025Architectures of Error: A Philosophical Inquiry into AI and Human Code Generationcited by 1
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- 2025CWM: An Open-Weights LLM for Research on Code Generation with World Models
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- 2024WorldCoder, a Model-Based LLM Agent: Building World Models by Writing Code and Interacting with the Environment
- 2026Distilling Game Code World Model Generation into Lightweight Large Language Models
- 2026Code to Control: Synthesizing Parameterized Reactive Controllers
- 2026PatchWorld: Gradient-Free Optimization of Executable World Models for Agent Environments
- 2026Belief-Calibrated Optimization: An Explicit World Model for Agentic Optimization
- 2025Code World Models for General Game Playing