ConceptNet Query API

openapi: 3.2.0
info:
  title: ConceptNet REST Concepts Query 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: Query
  description: Complex multi-parameter edge queries
paths:
  /query:
    get:
      operationId: queryEdges
      summary: Query edges with multiple criteria
      description: Performs a complex query against the ConceptNet edge store using any combination of start, end, rel, node, other, and sources parameters. All parameters are optional but at least one must be provided. Results are returned as a paginated JSON-LD edge list. This is the most flexible endpoint for slicing the knowledge graph by subject, object, relation type, or data source simultaneously.
      tags:
      - Query
      parameters:
      - name: start
        in: query
        description: ConceptNet URI for the subject (start) node of edges
        required: false
        schema:
          type: string
          example: /c/en/dog
      - name: end
        in: query
        description: ConceptNet URI for the object (end) node of edges
        required: false
        schema:
          type: string
          example: /c/en/animal
      - name: rel
        in: query
        description: Relation URI to filter by (e.g. /r/IsA or /r/UsedFor)
        required: false
        schema:
          type: string
          example: /r/IsA
      - name: node
        in: query
        description: URI matching either the start or end position of edges. Cannot be combined with the "other" parameter using the same URI.
        required: false
        schema:
          type: string
          example: /c/en/music
      - name: other
        in: query
        description: URI matching the position opposite to "node". Used together with "node" to find edges where node appears on one side and other appears on the other.
        required: false
        schema:
          type: string
      - name: sources
        in: query
        description: Source URI to restrict results to a specific data source
        required: false
        schema:
          type: string
          example: /s/resource/wordnet/3.1
      - $ref: '#/components/parameters/offset'
      - $ref: '#/components/parameters/limit'
      responses:
        '200':
          description: Paginated list of matching edges
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/EdgeList'
        '400':
          description: Invalid query parameters
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
components:
  schemas:
    EdgeList:
      type: object
      description: Paginated list of edges
      properties:
        '@context':
          type: array
          items:
            type: string
        '@id':
          type: string
          description: URI of this query result
        edges:
          type: array
          items:
            $ref: '#/components/schemas/Edge'
        view:
          $ref: '#/components/schemas/Pagination'
    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
    Pagination:
      type: object
      description: Pagination metadata for list responses
      properties:
        '@id':
          type: string
          description: URI of the current page
        paginatedProperty:
          type: string
          description: Property name that contains the paginated items
          example: edges
        firstPage:
          type: string
          description: URI of the first page
        nextPage:
          type: string
          description: URI of the next page (absent on last page)
        previousPage:
          type: string
          description: URI of the previous page (absent on first page)
        comment:
          type: string
          description: Human-readable summary of current result range
          example: Results 1-20 of 143
    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
  parameters:
    limit:
      name: limit
      in: query
      description: Maximum number of results to return (0-1000)
      required: false
      schema:
        type: integer
        minimum: 0
        maximum: 1000
        default: 20
    offset:
      name: offset
      in: query
      description: Number of results to skip for pagination (0-100000)
      required: false
      schema:
        type: integer
        minimum: 0
        maximum: 100000
        default: 0