openapi: 3.2.0
info:
  title: FreiDok plus JSON Publications API
  version: v1
  x-generated: '2026-09-01'
  x-method: probed
  x-source: Written from live probes of https://freidok.uni-freiburg.de/jsonApi/v1/ on 2026-09-01. Every path, parameter, status code and response field below was observed in an actual HTTP response; nothing is inferred from vendor documentation. The University of Freiburg does not publish an OpenAPI description of this API.
  x-operator: institution
  description: Read-only JSON API of FreiDok plus, the institutional repository, university bibliography and research documentation system operated by the Universitätsbibliothek Freiburg (University of Freiburg library) on the university's own infrastructure at freidok.uni-freiburg.de.
  contact:
    name: Universitätsbibliothek Freiburg — FreiDok plus
    url: https://www.ub.uni-freiburg.de/
  license:
    name: Not stated by the operator
servers:
- url: https://freidok.uni-freiburg.de/jsonApi/v1
  description: Production, anonymous read access
tags:
- name: Publications
paths:
  /publications:
    get:
      tags:
      - Publications
      operationId: listPublications
      summary: List publication metadata records
      description: 'Returns publication records from the university bibliography. Probed 2026-09-01: numFound 267771.'
      parameters:
      - $ref: '#/components/parameters/maxRows'
      - $ref: '#/components/parameters/start'
      - name: year
        in: query
        required: false
        description: 'Restricts results to a publication year. Probed: year=2025 narrowed numFound from 267771 to 7696.'
        schema:
          type: integer
      - name: instId
        in: query
        required: false
        description: 'Restricts results to publications affiliated with a FreiDok institution id. Probed: instId=2517 narrowed numFound to 267.'
        schema:
          type: integer
      responses:
        '200':
          description: A publication result envelope
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ResultEnvelope'
        '400':
          $ref: '#/components/responses/BadRequest'
components:
  responses:
    BadRequest:
      description: Invalid parameter value
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          examples:
            maxRowsOutOfRange:
              value:
                statusCode: 400
                errorCode: 0
                errorMsg: invalid value for maxRows (1-100)
  parameters:
    start:
      name: start
      in: query
      required: false
      description: 'Zero-based result offset, echoed back in the response envelope. Probed: start=10. NOTE the parameters named in some third-party descriptions of this API — startitem and maxitems — were probed on 2026-09-01 and are silently ignored by the server.'
      schema:
        type: integer
        minimum: 0
        default: 0
    maxRows:
      name: maxRows
      in: query
      required: false
      description: Page size. Server default 20. Probed range 1-100; maxRows=101 and maxRows=200 both return HTTP 400 with errorMsg "invalid value for maxRows (1-100)". maxRows=0 returns 200 with an empty docs array and the full numFound, which is a usable count-only call.
      schema:
        type: integer
        minimum: 0
        maximum: 100
        default: 20
  schemas:
    Error:
      type: object
      description: Error envelope observed on 400 and 404 responses.
      required:
      - statusCode
      - errorCode
      - errorMsg
      properties:
        statusCode:
          type: integer
        errorCode:
          type: integer
        errorMsg:
          type: string
          description: Human-readable message
          German or English: null
    ResultEnvelope:
      type: object
      description: Envelope returned by every collection endpoint.
      required:
      - numFound
      - start
      - maxRows
      - type
      - lang
      - docs
      properties:
        numFound:
          type: integer
          description: Total records matching the query
        start:
          type: integer
          description: Offset of the first returned record
        maxRows:
          type: integer
          description: Number of records requested
        type:
          type: string
          description: Record type of this collection
          enum:
          - publication
          - person
          - institution
          - project
        lang:
          type: string
          description: Language of the label values, e.g. de
        docs:
          type: array
          description: Records. Field sets differ per type; every record carries id and link, and each observed type is described in json-schema/university-of-freiburg-freidok-plus-response-schema.json.
          items:
            type: object