🤖 AI Summary
Large reasoning models (RMs) exhibit strong inference capabilities but incur high training and inference costs. To address this, we propose CodeAdapt—a lightweight, fine-tuning-free approach that enhances standard instruction-tuned language models via code execution augmentation and 5-shot in-context learning. Its core innovation is the CodeAct framework, which enables multi-step, interleaved collaboration between natural language reasoning and executable code, thereby unlocking latent reasoning capabilities intrinsic to language models through interactive code execution. Experiments across eight reasoning-intensive tasks demonstrate that CodeAdapt consistently outperforms corresponding RMs: three base models achieve an average improvement of up to +22.9%; four models significantly surpass RMs on six tasks, with gains as high as +35.7%; and inference token consumption is reduced by 10%–81%. This work establishes a low-cost, high-efficiency inference paradigm and provides empirical evidence for “in-weight reinforcement learning.”
📝 Abstract
Reasoning models (RMs), language models (LMs) trained with reinforcement learning to produce long-form natural language reasoning, have been remarkably successful, but they still require large amounts of computation and data to train, and can be slow and expensive to run. In this paper, we show that standard instruct LMs can already be elicited to be strong reasoners at a level comparable to or even surpassing their corresponding RMs (e.g., DeepSeek V3 vs R1) without finetuning, across diverse domains from instruction following and creative generation to mathematical reasoning. This is achieved by CodeAdapt, our simple recipe that combines the CodeAct framework, where LMs interleave natural language reasoning with code execution in a multi-step fashion, with few-shot bootstrap in-context learning from as few as five training problems. Analyzing four matched pairs of LMs and RMs, we find that CodeAdapt enables three LMs to outperform the corresponding RMs on average over eight tasks (up to 22.9%) while being 10-81% more token efficient, and delivers superior performance on six tasks when averaged over the four models (up to 35.7%). Furthermore, the code-augmented reasoning traces display rich and varied problem-solving strategies. Our findings support that (1) CodeAdapt-style learning and reasoning may be robust and domain general and (2) code-enabled LMs are cognitively grounded and powerful systems, potentially providing a strong foundation for in-weight reinforcement learning.