This Workflow Architecture Specification v5.0, a technical framework for building modular, FDA-compliant AI systems in precision medicine. The system replaces monolithic workflows with a library of shared bricks, which are reusable sub-workflows that perform specific tasks like data normalization, genomic risk calculation, and report generation. A centralized Universal Data Envelope ensures seamless communication between components by standardizing JSON structures and maintaining a mandatory audit trail for clinical accountability. Integration with LLM-driven prompt generators and specialized databases like Supabase and Neo4j allows the platform to synthesize complex patient data into actionable clinical insights. This architecture prioritizes scalability and regulatory adherence, transforming organ-specific engines into thin orchestrators that call upon the standardized brick library. Ultimately, the documentation serves as a canonical reference for migrating legacy medical workflows into a highly structured, interoperable, and auditable digital health ecosystem.