National Energy System Operator (NESO) website screenshot

National Energy System Operator (NESO)

The National Energy System Operator (NESO) is Great Britain's publicly owned, operationally independent electricity system operator and whole-energy system planner, created on 1 October 2024 when the UK government purchased National Grid Electricity System Operator Limited and folded in gas system planning from National Gas Transmission. NESO balances the GB electricity system in real time, runs the connections queue, publishes Future Energy Scenarios, and sits at the centre of the value chain between generators, interconnectors, transmission and distribution networks, and suppliers. Its API posture is the sector's classic split, and NESO lands firmly on the open side of that split. Market and system data is genuinely open and anonymous - the NESO Data Portal exposes 128 datasets over a public CKAN API at api.neso.energy with no key, no account and no application, all under the permissive NESO Open Data Licence, and the Carbon Intensity API for Great Britain that NESO develops is one of the most openly consumed public energy APIs in the world. There is no consumer data surface at all, and none is expected, because NESO holds no retail customer relationships, Britain has no consumer energy data-portability mandate comparable to the Australian Consumer Data Right, and smart-meter consumption data travels through the licensed Smart DCC monopoly rather than through the system operator. NESO's open-data obligation comes from Ofgem's Data Best Practice Guidance embedded in its RIIO-2 licence, and unlike most of the sector that obligation is visibly implemented rather than merely claimed.

National Energy System Operator (NESO) publishes 2 APIs on the APIs.io network. Tagged areas include Energy, United Kingdom, Electricity, Energy Markets, and Grid.

National Energy System Operator (NESO)’s developer surface includes authentication, documentation, developer portal, API reference, support, product news, and 23 more developer resources.

31.6/100 thin ▬ flat Agent 19/100 agent aware Full breakdown ↓
scored 2026-08-20 · rubric v0.12.0
AccessFreeOpen⚡ Free to try
2 APIs 1 MCP Servers
EnergyUnited KingdomElectricityEnergy MarketsGridOpen DataCarbonRenewablesGasDemand Response

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-20 · rubric v0.12.0
Composite quality — 31.6/100 · thin
Contract Quality 0.0 / 21
Developer Ergonomics 7.6 / 17
Access Clarity 3.6 / 17
Operational Transparency 4.9 / 11
Contract Governance 0.5 / 10
Discoverability 7.4 / 9
Regulatory Posture 6.3 / 15
Agent readiness — 19/100 · agent aware
Machine-Readable Contract 0 / 18
Agentic Access Contract 0 / 10
Documented Reversibility 0 / 6
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 8 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 5 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 3 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Regulatory Posture applies to this provider. Its tags matched the Energy & Utilities regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.
The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/neso: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 2

Individual APIs this provider publishes, each with its own machine-readable definition.

NESO Data Portal API

The public CKAN 2.8.7 API behind the NESO Data Portal, serving 128 open datasets covering GB electricity demand, generation, balancing, ancillary services, constraints, intercon...

Carbon Intensity API

The official Carbon Intensity API for Great Britain, developed by NESO, giving national and regional carbon intensity of GB electricity - actual, forecast up to 96+ hours ahead,...

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

National Energy System Operator (NESO) MCP Server

NESO operates NO first-party MCP server. This is a CANDIDATE tool design for one, derived from the two live anonymous APIs. Both surfaces are unusually well suited to MCP: no au...

MCP SERVER

Rate Limits 1

Documented rate limits and quota policies.

Neso Rate Limits

3 limits

RATE LIMITS

Security Posture 3

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Neso Authentication

none · 0 schemes

SECURITY

Neso Domain Security

TLSv1.3 · HSTS · DNSSEC · DMARC

SECURITY

Neso Vulnerability Disclosure

Hackerone · security.txt · contact published

SECURITY

Resources

Get Started 1

Portal, sign-up, and the first successful call

Documentation 2

Reference material describing how the API behaves

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

Design & Contract 5

Pagination, idempotency, versioning, errors, and events

Build 2

SDKs, sample code, and the tooling you integrate with

Access & Security 5

Authentication, authorization, and security posture

Operate 3

Status, limits, changes, and where to get help

Commercial 2

Pricing, plans, and the legal terms of use

Company 4

The organization behind the API

Other 1

Properties that don't map to a standard resource type

Source (apis.yml)

apis.yml Raw ↑
aid: neso
url: https://raw.githubusercontent.com/api-evangelist/neso/refs/heads/main/apis.yml
name: National Energy System Operator (NESO)
kind: company
description: The National Energy System Operator (NESO) is Great Britain's publicly owned, operationally independent electricity
  system operator and whole-energy system planner, created on 1 October 2024 when the UK government purchased National Grid
  Electricity System Operator Limited and folded in gas system planning from National Gas Transmission. NESO balances the
  GB electricity system in real time, runs the connections queue, publishes Future Energy Scenarios, and sits at the centre
  of the value chain between generators, interconnectors, transmission and distribution networks, and suppliers. Its API posture
  is the sector's classic split, and NESO lands firmly on the open side of that split. Market and system data is genuinely
  open and anonymous - the NESO Data Portal exposes 128 datasets over a public CKAN API at api.neso.energy with no key, no
  account and no application, all under the permissive NESO Open Data Licence, and the Carbon Intensity API for Great Britain
  that NESO develops is one of the most openly consumed public energy APIs in the world. There is no consumer data surface
  at all, and none is expected, because NESO holds no retail customer relationships, Britain has no consumer energy data-portability
  mandate comparable to the Australian Consumer Data Right, and smart-meter consumption data travels through the licensed
  Smart DCC monopoly rather than through the system operator. NESO's open-data obligation comes from Ofgem's Data Best Practice
  Guidance embedded in its RIIO-2 licence, and unlike most of the sector that obligation is visibly implemented rather than
  merely claimed.
accessModel:
  pricing: free
  onboarding: open
  trial: false
  try_now: true
  public: true
  label: Free - Open, no registration
  confidence: high
  source:
  - probe
  generated: '2026-07-27'
  method: observed
image: https://www.neso.energy/themes/custom/neso_theme/logo.svg
tags:
- Energy
- United Kingdom
- Electricity
- Energy Markets
- Grid
- Open Data
- Carbon
- Renewables
- Gas
- Demand Response
created: '2026-07-27'
modified: '2026-07-27'
specificationVersion: '0.23'
apis:
- aid: neso:neso-data-portal-api
  name: NESO Data Portal API
  description: The public CKAN 2.8.7 API behind the NESO Data Portal, serving 128 open datasets covering GB electricity demand,
    generation, balancing, ancillary services, constraints, interconnectors, connection registers, network charges, the Demand
    Flexibility Service, and Future Energy Scenarios. Anonymous and unauthenticated - package_list, package_search, package_show,
    resource_search, resource_show, datastore_search and datastore_search_sql (PostgreSQL) all answer 200 with no key. All
    128 datasets carry the NESO Open Data Licence. NESO asks for a maximum of one request per second against the CKAN API
    and two requests per minute against the datastore.
  humanURL: https://www.neso.energy/data-portal/api-guidance
  baseURL: https://api.neso.energy/api/3/action
  tags:
  - Open Data
  - Energy Markets
  - Electricity
  - Demand
  - CKAN
  properties:
  - type: Documentation
    url: https://www.neso.energy/data-portal
  - type: APIReference
    url: https://www.neso.energy/data-portal/api-guidance
  - type: Licensing
    url: https://www.neso.energy/data-portal/neso-open-licence
  - type: RateLimits
    url: rate-limits/neso-rate-limits.yml
  - type: Authentication
    url: authentication/neso-authentication.yml
  - type: Conventions
    url: conventions/neso-conventions.yml
  - type: ErrorCatalog
    url: errors/neso-error-codes.yml
  - type: DataModel
    url: data-model/neso-data-model.yml
- aid: neso:neso-carbon-intensity-api
  name: Carbon Intensity API
  description: The official Carbon Intensity API for Great Britain, developed by NESO, giving national and regional carbon
    intensity of GB electricity - actual, forecast up to 96+ hours ahead, half-hourly generation mix, per-fuel emission factors,
    and regional breakdowns by DNO region, region id, or postcode. Fully anonymous REST/JSON over HTTPS with no API key and
    no registration; documented as a Slate reference site rather than as a downloadable OpenAPI contract.
  humanURL: https://carbon-intensity.github.io/api-definitions/
  baseURL: https://api.carbonintensity.org.uk
  tags:
  - Carbon
  - Electricity
  - Renewables
  - Grid
  - Open Data
  properties:
  - type: APIReference
    url: https://carbon-intensity.github.io/api-definitions/
  - type: Documentation
    url: https://carbonintensity.org.uk/
  - type: GitHubOrganization
    url: https://github.com/carbon-intensity
  - type: SourceCode
    url: https://github.com/carbon-intensity/api-definitions
  - type: TermsOfService
    url: https://github.com/carbon-intensity/terms
  - type: Authentication
    url: authentication/neso-authentication.yml
  - type: Conventions
    url: conventions/neso-conventions.yml
  - type: ErrorCatalog
    url: errors/neso-error-codes.yml
  - type: DataModel
    url: data-model/neso-data-model.yml
common:
- type: IssueTracker
  url: https://github.com/carbon-intensity/api-definitions/issues
- type: VulnerabilityDisclosure
  url: security/neso-vulnerability-disclosure.yml
- type: Security
  url: https://www.neso.energy/responsible-disclosure
- type: SecurityTxt
  url: well-known/neso-security.txt
- type: DomainSecurity
  url: security/neso-domain-security.yml
- type: WellKnown
  url: well-known/neso-well-known.yml
- type: Authentication
  url: authentication/neso-authentication.yml
- type: Conventions
  url: conventions/neso-conventions.yml
- type: RateLimits
  url: rate-limits/neso-rate-limits.yml
- type: ErrorCatalog
  url: errors/neso-error-codes.yml
- type: Lifecycle
  url: lifecycle/neso-lifecycle.yml
- type: Conformance
  url: conformance/neso-conformance.yml
- type: DataModel
  url: data-model/neso-data-model.yml
- type: Packages
  url: packages/neso-packages.yml
- type: MCPServer
  url: mcp/neso-mcp.yml
- type: AgentSkill
  url: skills/_index.yml
- type: LLMsTxt
  url: llms/neso-llms.txt
- type: Website
  url: https://www.neso.energy/
- type: Documentation
  url: https://www.neso.energy/data-portal/api-guidance
- type: Portal
  url: https://www.neso.energy/data-portal
- type: APIReference
  url: https://carbon-intensity.github.io/api-definitions/
- type: Licensing
  url: https://www.neso.energy/data-portal/neso-open-licence
- type: TermsOfService
  url: https://www.neso.energy/terms-and-conditions
- type: PrivacyPolicy
  url: https://www.neso.energy/privacy-policy
- type: Support
  url: https://www.neso.energy/contact-us
- type: GitHubOrganization
  url: https://github.com/carbon-intensity
- type: LinkedIn
  url: https://www.linkedin.com/company/neso-energy
- type: BlogRSS
  url: https://www.neso.energy/rss.xml
- type: News
  url: https://www.neso.energy/news
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com