The Architecture of Limitation (AoL) is a diagnostic research program investigating how reasoning systems behave when they encounter structural limits. Rather than evaluating claims according to truth or explanatory completeness, AoL examines the conditions under which reasoning remains proportionate to the structures that sustain it. The program develops through a corpus of experimental studies that introduce conceptual artifacts, institutional systems, and AI-mediated reasoning environments into constraint-governed interpretive frameworks. These experiments reveal recurring structural signals—including boundary tension, conceptual drift, and collapse—when reasoning exceeds its supporting conditions. Across the corpus, the Architecture of Limitation functions as a constraint-based validator architecture for observing reasoning behaviour under pressure. The present document provides an orientation to the research program, mapping the corpus of publications and describing the capability structure through which AoL investigates reasoning across philosophical, institutional, and computational domains. This work belongs to the Architecture of Limitation research program. The corpus investigates reasoning systems under structural constraint and is maintained as an evolving research program on Zenodo.