# ntu — error semantics observed on live surfaces.
generated: '2026-08-19'
method: probed
source: live probes 2026-08-19
provider: ntu
errors:

  - surface: api.ntu.edu.sg
    x-operator: institution
    status: 404
    content_type: application/json
    body: '{ "statusCode": 404, "message": "Resource not found" }'
    detail: >-
      A consistent machine-readable error envelope with a statusCode/message pair. It is the only
      structured error shape NTU serves from a host it owns outright. Not RFC 9457
      (application/problem+json), and there is no type, title, detail or instance member.
    rfc9457: false
    evidence:
      - url: https://api.ntu.edu.sg/openapi.json
        status: 404

  - surface: DR-NTU (Digital Repository) — DSpace-CRIS REST API
    x-operator: tenant
    detail: >-
      DSpace 7 returns HAL error documents with timestamp/status/error/message/path. That envelope
      is the DSpace platform's, shipped by 4Science, and is not NTU's design.
    rfc9457: false

  - surface: DR-NTU (Data) — Dataverse REST API
    x-operator: institution
    detail: >-
      Dataverse returns {"status":"ERROR","message":"..."} with the HTTP status. Could not be
      re-verified 2026-08-19: the edge returns a Citrix bot-management 403 (text/html,
      iso-8859-1, honeypot link to /trap.html) ahead of the application on every path, so the
      only error body reachable from here is the WAF's, not the API's.
    rfc9457: false
    evidence:
      - url: https://researchdata.ntu.edu.sg/api/info/version
        status: 403

summary:
  rfc9457_adoption: none
  structured_error_envelope: partial
  note: >-
    No error catalogue, error-code reference, or problem-type registry is published by NTU for any
    surface.