KEGG Database — Biological Pathway & Molecular Network Queries

Overview

KEGG (Kyoto Encyclopedia of Genes and Genomes) is a comprehensive bioinformatics resource for biological pathway analysis, molecular interaction networks, and cross-database ID conversion. Access is via a direct REST API with no authentication — all operations use simple HTTP GET requests returning tab-delimited text.

When to Use

• Mapping genes to biological pathways (e.g., "which pathways involve TP53?")
• Retrieving metabolic pathway details, gene lists, or compound structures
• Converting identifiers between KEGG, NCBI Gene, UniProt, and PubChem
• Checking drug-drug interactions from KEGG's pharmacological database
• Building pathway enrichment context (all genes per pathway for an organism)
• Cross-referencing compounds, reactions, enzymes, and pathways
• For Python-native multi-database queries (KEGG + UniProt + Ensembl in one script), prefer bioservices instead
• For pathway visualization, use KEGG Mapper (https://www.kegg.jp/kegg/mapper/) directly

Prerequisites