PatternWall: Constitutional Governance Middleware for AI Safety - A Pre-Filter Architecture for Model-Agnostic Adversarial Detection

PatternWall is a constitutional governance layer that intercepts prompts before they reach an AI model. In controlled testing against a 28-sequence adversarial corpus across five models, it intercepted every adversarial campaign. The system achieves 100% per-attack detection, a 96.4% per-attack hard block rate, identical results across all five models, zero false positives, and fully deterministic, auditable decisions.