generated: '2026-08-30'
method: probed
source: live error-path probes against https://api.www.lib.umd.edu/api/libtools, 2026-08-30
x-operator: institution
provider: University of Maryland College Park
providerId: university-of-maryland-college-park
description: >-
  Observed error behaviour of the University of Maryland's institution-operated surfaces, centred on
  the Libraries Website Tools API, recorded
  from live probes rather than from the contract. The contract declares only 200 and 422; the
  service actually returns 404 and, on one input, 500. Both gaps are recorded here rather than
  silently normalised into the refined OpenAPI.
mediaType: application/json
envelope:
  shape: '{"detail": "<string>"}'
  note: FastAPI default error envelope. Not documented upstream.
errors:
- status: 404
  reason: Not Found
  body: '{"detail":"Not Found"}'
  contentType: application/json
  evidence:
    url: https://api.www.lib.umd.edu/api/libtools/nope
    status: 404
  declared_in_contract: false
  note: Returned for any path outside the 13 declared operations.
- status: 422
  reason: Validation Error
  schema: '#/components/schemas/HTTPValidationError'
  declared_in_contract: true
  observed: false
  note: >-
    Declared on the six operations that take the availability query parameter. Not reproduced
    during probing — the one malformed value tried returned 500 instead.
- status: 500
  reason: Internal Server Error
  body: 'Internal Server Error'
  contentType: text/plain
  evidence:
    url: https://api.www.lib.umd.edu/api/libtools/mckeldin/details?availability=
    status: 500
  declared_in_contract: false
  note: >-
    An empty availability value produces an unhandled upstream failure with a plain-text body,
    not the declared 422 JSON envelope. This is the single contract-to-behaviour divergence found.
- status: 503
  reason: Service Unavailable
  surface: DRUM institutional repository
  evidence:
    url: https://drum.lib.umd.edu/
    status: 503
  note: >-
    Not this API. Recorded because the whole DRUM host, including its documented DSpace REST,
    OAI-PMH and OpenSearch endpoints at api.drum.lib.umd.edu, served a "Maintenance" page during
    this review. See x-coverage in apis.yml.
- status: 200
  reason: Token Required (ArcGIS error 499 inside a 200)
  surface: UMD Enterprise GIS — ArcGIS REST Services
  body: '{"error":{"code":499,"details":[],"message":"Token Required"}}'
  contentType: application/json
  evidence:
    url: https://gis.umd.edu/arcgis/rest/services/Navigation?f=json
    status: 200
  declared_in_contract: false
  note: >-
    Not this API either, and the most consequential error shape on any UMD-operated host: the
    transport status is 200 and the failure is only in the body. A reader grading this surface on
    status codes alone would score fourteen token-gated service folders as open. Recorded because
    probing status codes rather than bodies is exactly the error this measurement is meant to avoid.
gaps:
- No RFC 9457 problem+json anywhere; errors are the framework default envelope.
- No rate-limit error surface observed; no 429 was produced during probing.
- No documented error reference on the Open Data site for any of the library surfaces.