KEGG REST API
The KEGG REST API provides unified programmatic access to all KEGG databases through seven operations: INFO (database statistics and release notes), LIST (entry identifiers and names), FIND (keyword and molecular weight/formula search), GET (full entry retrieval in flat-file, KGML, JSON, image, or sequence formats), CONV (identifier conversion between KEGG and external databases such as NCBI, UniProt, PubChem, and ChEBI), LINK (cross-reference lookup between KEGG databases), and DDI (adverse drug-drug interaction queries). Databases covered include PATHWAY, BRITE, MODULE, KO, GENES, GENOME, COMPOUND, GLYCAN, REACTION, ENZYME, DISEASE, DRUG, NETWORK, VARIANT, and DGROUP. The API is restricted to academic users; commercial use requires a license from Pathway Solutions. Rate limit is 3 requests per second per client.