Kyoto Encyclopedia of Genes and Genomes (KEGG) ddi API

openapi: 3.1.0
info:
  title: KEGG REST conv ddi 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: ddi
  description: Find adverse drug-drug interactions
paths:
  /ddi/{dbentry}:
    get:
      operationId: getDrugInteraction
      summary: Get adverse drug-drug interactions for a single drug
      description: 'Find adverse drug-drug interactions for a single drug entry. Returns tab-delimited text listing interacting drug pairs and severity data. Drug entries can be specified using KEGG drug IDs (D prefix), NDC codes, or YJ codes.

        '
      tags:
      - ddi
      parameters:
      - name: dbentry
        in: path
        required: true
        description: 'A single KEGG drug identifier. Formats: KEGG drug ID (e.g., D00001), NDC code, or YJ code.

          '
        schema:
          type: string
          example: D00001
      responses:
        '200':
          description: Tab-delimited drug-drug interaction data
          content:
            text/plain:
              schema:
                type: string
              example: "D00001\tD00002\tCI\nD00001\tD00005\tprecaution\n"
        '400':
          description: Bad request
        '404':
          description: Not found
  /ddi/{dbentries}:
    get:
      operationId: getDrugInteractions
      summary: Get adverse drug-drug interactions for multiple drugs
      description: 'Find adverse drug-drug interactions among multiple drug entries. Returns tab-delimited text listing interacting drug pairs and their interaction severity. Drug entries can be specified using KEGG drug IDs, NDC codes, or YJ codes, separated by plus signs.

        '
      tags:
      - ddi
      parameters:
      - name: dbentries
        in: path
        required: true
        description: 'Multiple KEGG drug identifiers separated by plus signs (e.g., D00001+D00002+D00003).

          '
        schema:
          type: string
          example: D00001+D00002
      responses:
        '200':
          description: Tab-delimited drug-drug interaction data
          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