Overview
The Kyoto Encyclopedia of Genes and Genomes (KEGG) is a fundamental database resource used globally to integrate genomic, chemical, and systemic functional information. Its architecture is built upon the mapping of molecular-level datasets, generated by high-throughput sequencing, to higher-order functions of the cell and the organism. In the 2026 landscape, KEGG remains the authoritative benchmark for metabolic pathway reconstruction and orthology-based functional annotation. It operates through a multi-layered database structure: KEGG PATHWAY (system functions), KEGG BRITE (hierarchical classifications), KEGG MODULE (functional units), and KEGG ORTHOLOGY (molecular building blocks). For AI Solutions Architects, KEGG provides the essential ground-truth data required for training predictive biological models, enabling everything from metabolic engineering to personalized medicine. While individual web access remains available for academic researchers, large-scale data ingestion and commercial utilization require a specialized licensing model managed through Pathway Solutions, ensuring data integrity and sustainable curation of biological knowledge.