generated: '2026-08-30'
method: probed
source: >-
  Error responses observed 2026-08-30 against
  https://www.datafirst.uct.ac.za/dataportal/index.php/api
x-operator: institution
description: >-
  The error contract of the DataFirst NADA catalog API, established by
  deliberately malformed and unauthorized requests. Recorded because it is
  non-obvious: the service does NOT use 404, and it answers an authorization
  failure with a 400.
api: DataFirst Microdata Catalog API (NADA)
format: JSON envelope with `status` and `message` string fields.
no_problem_details: true
notes: >-
  RFC 9457 / RFC 7807 application/problem+json is NOT used. Content-Type on
  error responses is application/json.
errors:
  - http_status: 400
    status: failed
    message: IDNO-NOT-FOUND
    meaning: >-
      The study identifier does not resolve. Also returned when a NUMERIC id is
      passed where the persistent IDNO is required — /catalog/890 fails while
      /catalog/mwi-alpha-him-karonga-2002-2017-v1 succeeds.
    evidence:
      - url: https://www.datafirst.uct.ac.za/dataportal/index.php/api/catalog/890
        status: 400
        body: '{"status":"failed","message":"IDNO-NOT-FOUND"}'
      - url: https://www.datafirst.uct.ac.za/dataportal/index.php/api/catalog/data_files/890
        status: 400
        body: '{"status":"failed","message":"IDNO-NOT-FOUND"}'
  - http_status: 400
    status: ACCESS-DENIED
    message: Access denied
    meaning: The endpoint exists but is not open to anonymous callers.
    evidence:
      - url: https://www.datafirst.uct.ac.za/dataportal/index.php/api/collections
        status: 400
        body: '{"status":"ACCESS-DENIED","message":"Access denied"}'
  - http_status: 500
    status: null
    message: null
    meaning: >-
      Empty-bodied server error on endpoints the deployment does not implement.
      No envelope is returned at all.
    evidence:
      - url: https://www.datafirst.uct.ac.za/dataportal/index.php/api/tables
        status: 500
        body: ''
      - url: https://www.datafirst.uct.ac.za/dataportal/index.php/api/citations
        status: 500
        body: ''
  - http_status: 404
    status: null
    message: null
    meaning: >-
      The API ROOT itself 404s with an HTML page; only /catalog and its
      sub-paths are routed.
    evidence:
      - url: https://www.datafirst.uct.ac.za/dataportal/index.php/api
        status: 404
        content_type: text/html