specification: API Commons Rate Limits
specificationVersion: '0.1'
schema: https://raw.githubusercontent.com/api-evangelist/interface-research/main/schema/api-commons.yml#/$defs/RateLimits
provider: National Energy System Operator (NESO)
providerId: neso
generated: '2026-07-27'
method: searched
created: '2026-07-27'
modified: '2026-07-27'
tags:
  - Rate Limiting
  - Open Data
  - Energy
description: >-
  NESO publishes courtesy rate guidance in prose on the Data Portal API guidance
  page rather than enforcing a signalled quota. There are no RateLimit-* headers
  and no 429 responses were observed; the stated enforcement mechanism is IP
  blocking when a consumer degrades the service. The Carbon Intensity API
  publishes no rate limit at all.
sources:
  - https://www.neso.energy/data-portal/api-guidance
  - https://carbon-intensity.github.io/api-definitions/
headers:
  rateLimit: none
  requestId: x-amzn-requestid (Carbon Intensity API only)
responseCodes:
  throttled: none observed
enforcement:
  style: advisory
  mechanism: >-
    "If the data consumer is not following the best practise for using the API
    and therefore overloading the server which causes performance issues then we
    reserve the right to block that IP address."
  signalled_in_response: false
limits:
  - name: CKAN Action API requests
    api: NESO Data Portal API
    scope: consumer (IP)
    metric: requests_per_second
    limit: 1
    timeFrame: second
    binding: recommended
    source: https://www.neso.energy/data-portal/api-guidance
  - name: Datastore API requests
    api: NESO Data Portal API
    scope: consumer (IP)
    metric: requests_per_minute
    limit: 2
    timeFrame: minute
    binding: recommended
    note: >-
      Applies to datastore_search and datastore_search_sql, which query the
      PostgreSQL datastore and are resource-intensive over large datasets.
    source: https://www.neso.energy/data-portal/api-guidance
  - name: Carbon Intensity API
    api: Carbon Intensity API
    scope: consumer (IP)
    metric: unpublished
    limit: null
    timeFrame: null
    binding: none-published
    note: No rate limit is documented in the Carbon Intensity API reference.
efficiency_guidance:
  - Do not poll data files to detect change; call resource_show?id={resource_id} and compare the modification date.
  - Use datastore_search filters or datastore_search_sql to retrieve only the records needed rather than downloading whole resources.
plans:
  applicable: false
  detail: >-
    There are no tiers, no paid plans and no quota upgrades. All access is free,
    anonymous and open under the NESO Open Data Licence.
related:
  conventions: conventions/neso-conventions.yml