@pipeworx/elexon

Elexon BMRS Insights MCP — Great Britain electricity grid and wholesale market data. Keyless.

Part of Pipeworx — an MCP gateway connecting AI agents to 1683+ live data sources.

Tools

• generation_by_fuel(from, to) — half-hourly GB generation in MW per fuel type (FUELHH), plus a byFuel total per fuel over the window.

• system_demand(from, to) — half-hourly GB transmission system demand outturn in MW (ITSDO).

• elexon_list_datasets(search?) — the directory of all 84 BMRS datasets: code, title, and which window parameters its route takes. Search by keyword ("wind", "price", "forecast") to find a code before calling query_dataset.

• query_dataset(dataset, from, to, settlement_period?, date_param?) — records from any of the 84 datasets by code. The correct window parameters are chosen per dataset automatically.

• elexon_system_prices(settlement_date, settlement_period?) — GB imbalance prices (system buy / system sell, GBP/MWh) per settlement period, with net imbalance volume and price derivation code (DISEBSP). Elexon serves this outside /datasets, so query_dataset cannot reach it.

A GB settlement day has 48 half-hour settlement periods.

Related MCP server: Carbon Intensity MCP

Auth

None. No key, no signup, no quota we have hit.

The 404 that means two different things

Elexon answers 404 {"statusCode":404,"message":"Resource not found"} for both an unknown dataset code and a known code queried with the wrong window parameters, because the window parameters are part of route resolution. /datasets/MID?publishDateTimeFrom=... is a 404 even though MID exists and is one of the most-wanted datasets in the pack — MID's route takes from/to.

That is why this pack carries a DATASETS table instead of passing the code straight through. It maps each of the 84 codes to one of five window styles:

Consequences worth knowing:

• The six settlementDate datasets are served one settlement period at a time, so query_dataset needs settlement_period (1–48) for those. It says so by name rather than 404ing.

• An unrecognised code is rejected by the pack, before the upstream call, with the near-matches and the full code list in the message. It never books as a Pipeworx defect (fleet #584: 49 identical 404s in three hours, every one a caller guessing a code, all filed as our bug).

• A real code with an empty window returns zero records, not a 404. If you get a 404 from a code that exists, the window parameters were what was rejected.

• date_param overrides the lookup and is rarely needed. The legacy value "settlement" means settlementDateFrom/To, which only FUELHH and FUELINST accept; "settlementDate" is the per-period style above.

What callers actually guess

Measured from a day of live traffic, two classes of guess account for most of the wasted calls, and the pack now answers both:

• ENTSO-E B-flow codes. B1620, B1430 and B1440 were all tried. Elexon's spec records the mapping in its own summaries ("Actual Aggregated Generation Per Type (AGPT / B1620)"), so the pack resolves 16 B-codes onto the dataset that superseded them and reports resolved_from in the response.

• The imbalance price. SYSTEMPRICE, SYSTEMPRICES, CASH, IMBALPR, B1770 and B1780 were tried 14 times between them. None is a dataset code — GB system buy/sell prices live at /balancing/settlement/system-prices, which is what elexon_system_prices wraps. Those guesses now get pointed at it by name instead of a list of 84 codes, none of which is the one they want.

Regenerating the dataset table

Elexon adds datasets. The table in src/index.ts comes from the upstream OpenAPI spec — note it is served from the site root, not under the API base:

curl -s https://data.elexon.co.uk/swagger/v1/swagger.json

Read the /datasets/{CODE} paths; a dataset's window style is whichever of publishDateTimeFrom / from / settlementDate / measurementDateTimeFrom / submissionDateTimeFrom its parameters declare.

Data sources

• API base: https://data.elexon.co.uk/bmrs/api/v1

• OpenAPI spec: https://data.elexon.co.uk/swagger/v1/swagger.json

• Docs: https://bmrs.elexon.co.uk/api-documentation

Quick Start

Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):

{
  "mcpServers": {
    "elexon": {
      "url": "https://gateway.pipeworx.io/elexon/mcp"
    }
  }
}

What this endpoint actually serves

tools/list at https://gateway.pipeworx.io/elexon/mcp returns the tools in the table above plus the shared Pipeworx meta-tools — ask_pipeworx, discover_tools, search_within, remember/recall and the rest of the gateway-wide set. So the tool count you see is larger than this table: a single-pack endpoint currently lists roughly 30 shared tools alongside the pack's own. The connection's initialize response states its exact scope, and is the authoritative answer for a given day.

This is deliberate, not multiplexing by accident. The meta-tools are what let a scoped connection answer a question this pack does not cover — via ask_pipeworx, which routes across the whole catalog — without you adding a second MCP server. There is currently no way to mount a pack endpoint without them; if the extra schemas cost you more context than the routing is worth, connect to the full gateway once rather than to several pack endpoints.

Or connect to the full Pipeworx gateway to get every pack's tools listed directly, instead of just this one's:

{
  "mcpServers": {
    "pipeworx": {
      "url": "https://gateway.pipeworx.io/mcp"
    }
  }
}

Both URLs reach the same gateway and the same 1683+ data sources. The only difference is which pack's tools are listed directly; ask_pipeworx reaches all of them from either one.

No MCP client? Call it over HTTP

curl -X POST https://gateway.pipeworx.io/v1/tools/generation_by_fuel \
  -H 'Content-Type: application/json' \
  -d '{"from":"2024-06-01T00:00Z","to":"2024-06-01T01:00Z"}'

No account needed for the first calls. Inspect any tool: GET https://gateway.pipeworx.io/v1/tools/generation_by_fuel. Find one: POST https://gateway.pipeworx.io/v1/tools/search_packs with {"query":"..."}.

Standalone (no gateway account)

This package also runs as a local stdio MCP server — no Pipeworx account, no gateway round-trip:

{
  "mcpServers": {
    "elexon": {
      "command": "npx",
      "args": ["-y", "@pipeworx/mcp-elexon"]
    }
  }
}

Or run it directly to confirm it starts:

npx -y @pipeworx/mcp-elexon

It speaks MCP over stdin/stdout and answers initialize/tools/list/tools/call for only this pack's tools — none of the shared meta-tools the gateway connection above adds. Same source, same tools, no ask_pipeworx routing.

Using with ask_pipeworx

Instead of calling tools directly, you can ask questions in plain English — this works on the pack endpoint above as well as on the full gateway:

ask_pipeworx({ question: "your question about Elexon data" })

The gateway picks the right tool and fills the arguments automatically.

More

• Docs and guides

• pipeworx.io

License

MIT