name: Kyoto Encyclopedia of Genes and Genomes (KEGG)
description: >
  The Kyoto Encyclopedia of Genes and Genomes (KEGG) is an integrated database
  resource for understanding high-level functions and utilities of biological
  systems from molecular-level information derived from genome sequencing and
  other high-throughput experiments. The KEGG REST API at rest.kegg.jp provides
  programmatic access to KEGG databases covering biological pathways, metabolic
  networks, molecular interactions, drug targets, disease associations, chemical
  compounds, genomic sequences, and functional orthologs across thousands of
  organisms. The API exposes seven core operations — info, list, find, get,
  conv, link, and ddi — enabling identifier conversion, cross-database linking,
  keyword and structure searches, and full entry retrieval in text, KGML, and
  JSON formats. Academic use is free via the REST API; FTP and commercial access
  require subscriptions managed through NPO Bioinformatics Japan and Pathway
  Solutions.
url: https://www.kegg.jp/kegg/rest/
image: https://www.kegg.jp/favicon.ico
tags:
  - Bioinformatics
  - Genomics
  - Life Sciences
  - Pathways
  - Metabolomics
  - Drug Targets
  - Disease
  - Chemical Compounds
  - Enzymes
  - Orthology
created: "2026-06-13"
modified: "2026-06-13"
specificationVersion: "0.19"
apis:

  - name: KEGG REST API
    description: >
      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.
    image: https://www.kegg.jp/favicon.ico
    humanURL: https://www.kegg.jp/kegg/rest/
    baseURL: https://rest.kegg.jp
    tags:
      - Pathways
      - Metabolic Networks
      - Genomics
      - Drug Targets
      - Disease
      - Chemical Compounds
      - Enzymes
      - Identifier Conversion
      - Orthology
    properties:
      - type: documentation
        url: https://www.kegg.jp/kegg/rest/keggapi.html
      - type: terms-of-service
        url: https://www.kegg.jp/kegg/legal.html
      - type: rate-limits
        url: https://api-evangelist.github.io/kegg/rate-limits/kegg-rest-api.yml
      - type: plans
        url: https://api-evangelist.github.io/kegg/plans/kegg-rest-api.yml
      - type: finops
        url: https://api-evangelist.github.io/kegg/finops/overview.yml
    contact:
      - FN: KEGG Support
        url: https://www.kegg.jp/kegg/feedback.html

maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com