API Evangelist enhancements for Northern Powergrid Open Data Explore API v2.1

overlay: 1.0.0
info:
  title: API Evangelist enhancements for Northern Powergrid Open Data Explore API v2.1
  version: 1.0.0
extends: openapi/northern-powergrid-open-data-explore-api-v2-1-openapi.json
x-apievangelist:
  generated: '2026-07-27'
  method: generated
  source: >-
    Enhancements derived from the provider's own reference documentation and from live probes of
    https://northernpowergrid.opendatasoft.com/api/explore/v2.1 on 2026-07-27. This overlay never
    mutates the harvested spec; it records what we know that the published document leaves out.
  rationale: >-
    The published spec is structurally sound — 16 operations, all with operationIds, summaries and
    tags — but it declares 400/401/429/500 on every operation with no schema, no description and no
    example, omits the 404 the API actually returns, omits the OAuth 2.0 flow and the Authorization
    header form of the API key that the docs document, and carries no servers-level context for this
    tenant. Those are the gaps this overlay fills.
actions:
- target: $.info
  update:
    x-apievangelist-provider: northern-powergrid
    x-apievangelist-artifacts: https://github.com/api-evangelist/northern-powergrid
    x-apievangelist-verified: '2026-07-27'
    x-provider-name: Northern Powergrid
    x-provider-role: GB electricity distribution network operator (North East England, Yorkshire, northern Lincolnshire)
    x-regulatory-driver: Ofgem Data Best Practice Guidance, a licence condition under the RIIO-ED2 price control
    x-data-licence: Northern Powergrid Open Data Licence v1.0
    x-data-licence-url: https://northernpowergrid.opendatasoft.com/p/opendatalicence/
    x-catalog-size-observed: 102
    x-platform: Opendatasoft (Huwise)
- target: $.servers[0]
  update:
    description: Northern Powergrid open data portal, Explore API v2.1 (production; the only environment)
- target: $.components.securitySchemes
  update:
    apikeyHeader:
      type: apiKey
      in: header
      name: Authorization
      description: >-
        The provider-recommended way to pass an API key, documented in the reference but absent from
        the published spec. Format: "Authorization: Apikey <API_KEY>". Preferred over the apikey
        query parameter because headers are not retained in browser history or server logs.
    oauth2:
      type: oauth2
      description: >-
        OAuth 2.0 authorization-code flow for third-party applications acting on behalf of a portal
        user. RFC 6749 compliant with RFC 6750 bearer tokens; documented by the platform and
        confirmed live on this host on 2026-07-27. Absent from the published spec.
      flows:
        authorizationCode:
          authorizationUrl: https://northernpowergrid.opendatasoft.com/oauth2/authorize/
          tokenUrl: https://northernpowergrid.opendatasoft.com/oauth2/token/
          refreshUrl: https://northernpowergrid.opendatasoft.com/oauth2/token/
          scopes:
            all: Full access to the data the granting user can see on this domain. The only scope the platform supports.
- target: $.components.schemas
  update:
    error:
      type: object
      description: >-
        The error envelope this API actually returns. Not RFC 9457 problem+json — no type URI, no
        title, no instance — and served as application/json. Captured from live 400 and 404
        responses on 2026-07-27.
      properties:
        error_code:
          type: string
          description: Machine-readable PascalCase error identifier, e.g. ODSQLSyntaxError, ODSQLError, NotFoundResource, NotFoundURI.
          example: ODSQLSyntaxError
        message:
          type: string
          description: Human-readable explanation; for query errors it names the failing clause and character offset.
          example: "ODSQL syntax exception: unexpected ( at position 9 in BADSYNTAX((. Clause(s) containing the error(s): where."
      required: [error_code, message]
- target: $.paths['/catalog/datasets'].get.responses['400']
  update:
    description: >-
      Bad request — usually a malformed or invalid ODSQL clause. Body is the {error_code, message}
      envelope. Not retryable without changing the query.
    content:
      application/json:
        schema:
          $ref: '#/components/schemas/error'
        example:
          error_code: ODSQLSyntaxError
          message: "ODSQL syntax exception: unexpected ( at position 9 in BADSYNTAX((. Clause(s) containing the error(s): where."
- target: $.paths['/catalog/datasets'].get.responses['429']
  update:
    description: >-
      Daily request quota exhausted (5,000/day for anonymous callers). Back off until the
      X-RateLimit-Reset timestamp — the window is daily, not per-second. Safe to retry.
- target: $.paths['/catalog/datasets/{dataset_id}'].get.responses['400']
  update:
    description: Bad request. Body is the {error_code, message} envelope.
    content:
      application/json:
        schema:
          $ref: '#/components/schemas/error'
- target: $.paths['/catalog/datasets/{dataset_id}'].get.responses
  update:
    '404':
      description: >-
        The named dataset does not exist on this portal. Returned in practice but declared on no
        operation in the published spec. Verified live on 2026-07-27.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/error'
          example:
            error_code: NotFoundResource
            message: "The requested dataset nonexistent-dataset-xyz does not exist."
- target: $.paths['/catalog/datasets/{dataset_id}/records'].get
  update:
    x-result-limits:
      limit_max_without_group_by: 100
      limit_max_with_group_by: 20000
      offset_plus_limit_max_without_group_by: 10000
      offset_plus_limit_max_with_group_by: 20000
      bulk_alternative: Use the exports endpoints, which carry no result cap.
    x-agentic-access:
      action-class: connected
      consequence: read
      token:
        max-ttl: 3600
      audit: none
- target: $.paths['/catalog/datasets/{dataset_id}/records'].get.responses['429']
  update:
    description: >-
      Daily request quota exhausted. Both a global and a dataset-scoped counter apply; read
      X-RateLimit-Remaining and X-RateLimit-dataset-Remaining to tell which one tripped.