Environment — entry 009 of 18
National Grid ESO
This is Great Britain's electricity system operator's open-data portal, publishing generation mix, demand forecasts, and grid balancing datasets. The operator was transferred to public ownership and rebranded the National Energy System Operator (NESO) on 1 October 2024; the old data.nationalgrideso.com host no longer resolves at all, with the same CKAN data portal now living at neso.energy/data-portal. Its real CKAN gateway at api.neso.energy returns Access-Control-Allow-Origin: * on every response, resolving cors unknown -> yes.
National Grid ESO's open-data portal — now rebranded NESO, the National Energy System Operator, after transferring to public ownership on 1 October 2024 — runs on the CKAN data-catalog engine at api.neso.energy, exposing every published dataset through CKAN's generic /api/3/action/* interface. A live GET this run against package_list returned 129 real dataset names, and a live GET against datastore_search for the Historic GB Generation Mix dataset returned genuine rows going back to 2009, all keyless.
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<a href="https://greatapis.com/api/national-grid-eso/"><img src="https://greatapis.com/badge/national-grid-eso.svg" alt="Scored 94 on greatapis.com"></a>Auth quickstart
- No API key required for reading published datasets — live GETs this run against
package_listanddatastore_searchboth returned real data with zero credentials, and both carriedaccess-control-allow-origin: *(confirmed live this run; this had been an opencors: unknownon this entry until now). A CKAN API key only matters for write actions (uploading or editing datasets), which are out of scope for a read-only quickstart.
Your key is stored only in this browser (localStorage) and sent directly to the API — never to greatapis.
Read rows from the Historic GB Generation Mix dataset
GEThttps://api.neso.energy/api/3/action/datastore_search?resource_id=f93d1835-75bc-43e5-84ad-12472b180a98&limit=1
{"help":"https://api.neso.energy/api/3/action/help_show?name=datastore_search","success":true,"result":{"resource_id":"f93d1835-75bc-43e5-84ad-12472b180a98","fields":[{"type":"int","id":"_id"},{"type":"timestamp","id":"DATETIME"},{"...":"30+ more numeric fuel-mix and carbon-intensity fields"}],"records":[{"_id":7259,"DATETIME":"2009-06-01T05:00:00","GAS":13916.0,"COAL":4431.0,"CARBON_INTENSITY":353.0,"...":"remaining fuel-mix columns omitted"}],"total":308181}}Every CKAN action wraps its payload in this same {help, success, result} envelope, confirmed live this run. resource_id (here the Historic GB Generation Mix table, f93d1835-75bc-43e5-84ad-12472b180a98) identifies one specific table within a dataset — see the gotcha below on how to find one for a different dataset.
Try it
Developer reference
https://api.neso.energy/api/3/actionBest-practice limit of 1 request/second (CKAN API) and 2 requests/minute (Datastore API), with IP blocking for non-compliant overload
- GET/package_list
- GET/package_show?id={dataset}
- GET/datastore_search?resource_id={id}&limit={n}
Gotchas & limits
package_listonly gives you dataset names (slugs likehistoric-generation-mix), not theresource_idadatastore_searchcall actually needs — a live GET againstpackage_listthis run returned a plain array of names with no ids. To go from a dataset name to a queryableresource_id, callpackage_show?id=<dataset-name>first and read theresources[].idfield of its response; there's no shortcut that skips this lookup.- An unknown
resource_idfails with the dataset-level envelope still intact — a live GET this run againstdatastore_searchwith a made-up id returned HTTP 404{"help":...,"success":false,"error":{"message":"Not found: Resource \"...\" was not found.","__type":"Not Found Error"}}, so checksuccessanderror.messagerather than assuming a 404 means the whole API is down. - An unknown action name (a typo in the URL path itself, e.g.
/action/dataset_search) comes back as HTTP 400 with a bare JSON string body, not the usual{help, success, result}object — a live GET this run against/action/not_a_real_actionreturned exactly"Bad request - Action name not known: not_a_real_action". Code that always readsbody.successwill throw on this shape instead of the ordinary error path. - The legacy
data.nationalgrideso.comhost from this API's pre-rebrand docs no longer resolves at all — always useapi.neso.energy(confirmed live and CORS-enabled this run); the CKAN action names and resource ids themselves carried over unchanged across the rebrand.