ConceptNet Edges API

openapi: 3.2.0
info:
  title: ConceptNet REST Concepts Edges API
  description: ConceptNet is a freely available multilingual knowledge graph providing computers access to common-sense knowledge. The REST API exposes the full ConceptNet 5 knowledge graph via JSON-LD endpoints. Consumers can look up concept nodes by language and term, query edges by relation type, retrieve semantically related terms ranked by Numberbatch embedding similarity, compute pairwise relatedness scores between concepts, and normalize natural-language text into canonical ConceptNet URIs. No authentication or API key is required.
  version: '5.7'
  license:
    name: CC BY-SA 4.0
    url: https://creativecommons.org/licenses/by-sa/4.0/
  contact:
    name: ConceptNet Users Group
    url: https://groups.google.com/g/conceptnet-users
  x-website: https://conceptnet.io
  x-github: https://github.com/commonsense/conceptnet5
servers:
- url: https://api.conceptnet.io
  description: ConceptNet public API
tags:
- name: Edges
  description: Access individual edge (assertion) records
paths:
  /a/{edgeId}:
    get:
      operationId: getEdge
      summary: Look up an individual edge (assertion)
      description: Returns a JSON-LD edge object for the assertion identified by edgeId. Edge IDs are constructed from the start URI, relation URI, and end URI in the form /a/[/{rel}/,{start},/{end}/]. Each edge carries a weight, license, dataset, and source attribution.
      tags:
      - Edges
      parameters:
      - name: edgeId
        in: path
        description: Edge identifier path (URL-encoded brackets and slashes)
        required: true
        schema:
          type: string
          example: '[/r/IsA/,/c/en/example/,/c/en/instance/]'
      responses:
        '200':
          description: Edge assertion object
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Edge'
        '404':
          description: Edge not found
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
components:
  schemas:
    Error:
      type: object
      description: API error response
      properties:
        error:
          type: string
          description: Error type identifier
        details:
          type: string
          description: Human-readable error description
    Edge:
      type: object
      description: A single ConceptNet assertion (knowledge edge)
      properties:
        '@id':
          type: string
          description: Unique URI identifier for this edge
          example: /a/[/r/IsA/,/c/en/dog/,/c/en/animal/]
        start:
          $ref: '#/components/schemas/ConceptRef'
        end:
          $ref: '#/components/schemas/ConceptRef'
        rel:
          $ref: '#/components/schemas/RelationRef'
        surfaceText:
          type:
          - string
          - 'null'
          description: Natural-language sentence the assertion was derived from
          example: '[[A dog]] is a [[animal]].'
        weight:
          type: number
          format: float
          description: Confidence weight of the assertion (typically 1.0+)
          example: 3.46
        license:
          type: string
          description: Creative Commons license identifier
          example: cc:by/4.0
        dataset:
          type: string
          description: Dataset URI this assertion came from
          example: /d/verbosity
        sources:
          type: array
          items:
            $ref: '#/components/schemas/SourceRef'
    RelationRef:
      type: object
      description: Reference to a ConceptNet relation type
      properties:
        '@id':
          type: string
          description: Relation URI
          example: /r/IsA
        label:
          type: string
          description: Human-readable relation name
          example: IsA
    ConceptRef:
      type: object
      description: Reference to a ConceptNet concept node
      properties:
        '@id':
          type: string
          description: ConceptNet URI
          example: /c/en/dog
        label:
          type: string
          description: Human-readable label
          example: dog
        language:
          type: string
          description: BCP-47 language code
          example: en
        term:
          type: string
          description: Concept URI (same as @id)
          example: /c/en/dog
        sense_label:
          type: string
          description: Part-of-speech or sense label if applicable
          example: n
    SourceRef:
      type: object
      description: Reference to a data source or contributor
      properties:
        '@id':
          type: string
          description: Source URI
          example: /s/resource/verbosity