openapi: 3.1.0
info:
  title: KEGG REST conv API
  description: 'The Kyoto Encyclopedia of Genes and Genomes (KEGG) REST API 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; commercial use requires a license from Pathway Solutions. Rate limit is 3 requests per second per client.

    '
  version: 1.0.0
  contact:
    name: KEGG Support
    url: https://www.kegg.jp/kegg/feedback.html
  termsOfService: https://www.kegg.jp/kegg/legal.html
  license:
    name: Academic Use Only
    url: https://www.kegg.jp/kegg/legal.html
servers:
- url: https://rest.kegg.jp
  description: KEGG REST API server
tags:
- name: conv
  description: Convert identifiers between KEGG and external databases
paths:
  /conv/{target_db}/{source_db}:
    get:
      operationId: convertIdentifiers
      summary: Convert identifiers between databases
      description: 'Convert identifiers between KEGG and external databases. Returns a tab-delimited mapping of source to target identifiers. Supports conversion between KEGG gene identifiers and NCBI Gene IDs, NCBI Protein IDs, and UniProt accessions, as well as between KEGG compound IDs and PubChem CIDs and ChEBI IDs.

        '
      tags:
      - conv
      parameters:
      - name: target_db
        in: path
        required: true
        description: 'Target database for conversion. For genes: ncbi-geneid, ncbi-proteinid, uniprot, or a KEGG organism code. For chemicals: pubchem, chebi, or compound.

          '
        schema:
          type: string
          example: ncbi-geneid
      - name: source_db
        in: path
        required: true
        description: 'Source database or organism code. For genes: ncbi-geneid, ncbi-proteinid, uniprot, or a KEGG organism code. For chemicals: pubchem, chebi, or compound.

          '
        schema:
          type: string
          example: hsa
      responses:
        '200':
          description: Tab-delimited identifier mapping
          content:
            text/plain:
              schema:
                type: string
              example: "ncbi-geneid:10458\thsa:10458\nncbi-geneid:1131\thsa:1131\n"
        '400':
          description: Bad request
        '404':
          description: Not found
  /conv/{target_db}/{dbentries}:
    get:
      operationId: convertEntryIdentifiers
      summary: Convert specific entry identifiers
      description: 'Convert specific KEGG entry identifiers to their equivalents in an external database, or convert external database identifiers to KEGG identifiers. Up to 10 entries per request.

        '
      tags:
      - conv
      parameters:
      - name: target_db
        in: path
        required: true
        description: 'Target database for conversion (e.g., ncbi-geneid, uniprot, pubchem, chebi, or a KEGG organism code).

          '
        schema:
          type: string
      - name: dbentries
        in: path
        required: true
        description: 'One or more entry identifiers separated by plus signs. Maximum 10 entries per request.

          '
        schema:
          type: string
          example: ncbi-geneid:10458+ncbi-geneid:1131
      responses:
        '200':
          description: Tab-delimited identifier mapping
          content:
            text/plain:
              schema:
                type: string
        '400':
          description: Bad request
        '404':
          description: Not found
externalDocs:
  description: KEGG API Documentation
  url: https://www.kegg.jp/kegg/rest/keggapi.html