generated: '2026-06-20'
method: searched
source: >-
  Live response headers captured from
  https://ukpowernetworks.opendatasoft.com/api/explore/v2.1/catalog/datasets?limit=1 on 2026-07-27,
  plus the 429 quota response declared in openapi/uk-power-networks-explore-api-v2-1-openapi.json.
signaling:
  headers:
  - name: X-RateLimit-Limit
    scope: domain
    observed: '10000'
  - name: X-RateLimit-Remaining
    scope: domain
    observed: '9822'
  - name: X-RateLimit-Reset
    scope: domain
    observed: '2026-07-28 00:00:00+00:00'
    format: absolute timestamp, not a delta
  - name: X-RateLimit-dataset-Limit
    scope: per-dataset
    observed: declared in access-control-expose-headers; not returned on the catalogue call probed
  - name: X-RateLimit-dataset-Remaining
    scope: per-dataset
    observed: declared in access-control-expose-headers
  - name: X-RateLimit-dataset-Reset
    scope: per-dataset
    observed: declared in access-control-expose-headers
  cors_exposed: true
  note: >-
    The rate-limit headers are listed in access-control-expose-headers, so browser clients can read
    their own budget cross-origin.
rate_limits:
- tier: anonymous
  limit_count: 10000
  interval: day
  scope: domain
  reset: midnight UTC
  authenticated: false
  source: X-RateLimit-Limit header on an anonymous HTTP 200
  verified: '2026-07-27'
- tier: per-dataset
  limit_count: null
  interval: unknown
  scope: dataset
  authenticated: null
  source: X-RateLimit-dataset-Limit header declared in access-control-expose-headers
  note: >-
    A per-dataset budget demonstrably exists alongside the domain budget, but no value was observed
    anonymously and UK Power Networks publishes no figure. Recorded as present-with-unknown-ceiling
    rather than guessed.
over_limit:
  status: 429
  body_fields: [errorcode, error, call_limit, limit_time_unit, reset_time]
  spec_example_call_limit: 10000
  spec_example_unit: day
  guidance: >-
    Back off to reset_time. Because every operation is a safe GET, retry after the window resets is
    always safe. For bulk extraction use /catalog/datasets/{dataset_id}/exports/{format}, which
    returns a whole dataset in one call instead of burning the budget on pagination.
published_policy_url: null
published_policy_note: >-
  UK Power Networks documents no rate-limit policy page. Everything above was measured from live
  response headers and the OpenAPI quota response, not read from a published limits page.
related:
  conventions: conventions/uk-power-networks-conventions.yml
  errors: errors/uk-power-networks-problem-types.yml