ACTS

ACTS: Agentic Chain-of-Thought Steering for efficient and controllable LLM reasoning

Researchers introduce Agentic Chain-of-Thought Steering (ACTS), a framework that formulates inference-time reasoning control as a Markov decision process, where a controller agent adaptively steers a frozen reasoner by issuing reasoning strategy directives and steering phrases at each step. The controller is initialized from synthetic steering trajectories with multi-budget augmentation and further optimized via reinforcement learning with budget-conditioned reward shaping. ACTS matches full-thinking performance with significant token savings and enables controllable accuracy-efficiency trade-offs across multiple benchmarks and reasoner models.