ReasoningLens: Hierarchical Visualization and Diagnostic Auditing for Large Reasoning Models
Authors: name: Jun Zhang, name: Jiasheng Zheng, name: Boxi Cao, name: Yaojie Lu, name: Hongyu Lin, name: Jia Zheng, name: Xianpei Han, name: Le Sun

The emergence of Large Reasoning Models has introduced exceptionally long Chain-of-Thought traces, creating a transparency burden where critical logic is often buried under massive procedural text. To address this, we present ReasoningLens, an open-source framework designed for the hierarchical visualization and diagnostic auditing of complex reasoning chains. ReasoningLens addresses information necropsy by: (1) structuring traces into interactive hierarchies that separate high-level strategy from low-level execution; (2) leveraging an agentic auditor for automated error detection and tool-augmented verification; and (3) synthesizing systemic reasoning profiles to reveal model-specific blind spots. By transforming unstructured walls of text into actionable insights, ReasoningLens provides a modular foundation for interpreting, debugging, and optimizing the next generation of reasoning-centric AI.