Voltstack Data API

Data API v1

A read-only REST API over the same feed layer the product runs on. Key every request: the data API key goes in the X-API-Key header, and you can request one at research@voltstack.energy. As at 22 September 2026 a keyed request is answered at full depth on every path below, and a request carrying no key is answered as a labelled sample: the envelope gains a sample block, current feeds serve their usual recent window, and history is limited to the most recent 30 days. Build every integration keyed: a keyed call is never narrowed or labelled, whatever happens to anonymous access. Responses are JSON with a live flag and a data-age timestamp, so you can tell exactly what you are looking at, the same honesty rule as /status.

Base URL

https://api.voltstack.energy/v1

Try it (bring a key)

curl -H "X-API-Key: YOUR_KEY" \
  https://api.voltstack.energy/v1/power/day-ahead

History, with its required window

curl -H "X-API-Key: YOUR_KEY" \
  "https://api.voltstack.energy/v1/history/day-ahead?zone=DE_LU&from=2026-01-01&to=2026-07-01"

With no key, as at 22 September 2026: a labelled sample

HTTP 200, the same envelope plus:
"sample":{"sample":true,"window":"recent","detail":"Anonymous sample tier. Full depth requires a data API key …"}

With no key, as at 22 September 2026: history before the 30-day window

HTTP 401
{"error":"api-key-required","detail":"Anonymous access is limited to a 30-day sample window. Full-depth history requires a data API key in the X-API-Key header. Request one at research@voltstack.energy."}

PAUSEDAs at 24 September 2026 the endpoints that carry JAO, Nord Pool N2EX or netztransparenz.de data are paused while we confirm redistribution rights with those publishers, so they are not listed below. Each answers HTTP 451 to every request, keyed or not, with {"error":"unavailable","reason":"This dataset is paused while we confirm redistribution rights with its publisher."}

API KEYAs at 22 September 2026 this applies to every endpoint listed below, current feeds included: a key is what moves each of them from the labelled sample to full depth, and no endpoint answers an unkeyed request more fully than another. The badges on individual rows flag the other things a call needs, not the key.

Power

GET/v1/power/day-aheadLIVE
Day-ahead auction prices for the 12 configured European bidding zones, via ENTSO-E. ENTSO-E carries no GB price, so the payload holds 11.
GET/v1/power/flowsLIVE
Cross-border physical flows on the major interconnectors.
GET/v1/power/generation?country=DE&range=1WLIVE
Generation mix by fuel type. GB is served from Elexon; other zones from ENTSO-E.
GET/v1/power/merit-order?country=DELIVE
Merit-order curve snapshot for a zone.
GET/v1/power/imbalanceLIVE
Imbalance prices (ENTSO-E, dual-price zones included). The German control-area rows are withheld while netztransparenz.de confirms redistribution rights.
GET/v1/power/ummLIVE
REMIT urgent market messages (outages and capacity events).
GET/v1/power/fr-nuclearLIVE
French nuclear fleet availability.
GET/v1/power/fr-generation-forecast?filiere=SOLAR&horizon=D-1LIVE
French wind and solar generation forecasts and RTE's purchase-obligation aggregate, in MW by horizon, as RTE publishes them (Source: RTE).
GET/v1/power/nordic-hydroLIVE
Nordic hydro reservoir levels.
GET/v1/power/gb-balancingLIVE
GB balancing mechanism: accepted offers/bids vs MID (Elexon BOD/BOALF).

Gas

GET/v1/gas/storageLIVE
EU gas storage levels and flows (GIE AGSI+).
GET/v1/gas/lngLIVE
LNG terminal inventories and sendout (GIE ALSI+).
GET/v1/gas/pipeline-flowsLIVE
Cross-border pipeline flows (ENTSOG).
GET/v1/gas/gb-systemLIVE
GB gas system: demand, supply mix, linepack (National Gas).
GET/v1/gas/norway-eventsLIVE
Norwegian gas system events: field and terminal unavailability as Gassco REMIT urgent market messages. Events, not flows.

Carbon

GET/v1/carbon/eua-auctionsLIVE
EU Allowance primary auction results by auctioning entity: clearing price, volume, cover ratio and bidders (Source: EEX). No spot or futures prices.

Weather

GET/v1/weather?regions=EU_DE,EU_FR&days=10LIVE
10-day temperature and wind forecasts by market region (Open-Meteo).
GET/v1/weather/forecast-riskLIVE
Forecast-error risk: run-to-run drift on wind and demand.

History

GET/v1/history/day-ahead?zone=DE_LU&from=2026-01-01&to=2026-07-01FROM/TO REQUIRED
Historical day-ahead prices by zone.
GET/v1/history/realized-vol?zone=DE_LU&from=…&to=…FROM/TO REQUIRED
Realized volatility computed from settled prices.
GET/v1/history/gas-storage?from=…&to=…FROM/TO REQUIRED
Historical EU storage levels.
GET/v1/history/lng-terminals?from=…&to=…FROM/TO REQUIRED
Historical LNG terminal data.
GET/v1/history/commodities?from=…&to=…FROM/TO REQUIRED
Commodity reference series (FRED).

Benchmarks

GET/v1/benchmarks/de-bessLIVE
DE battery storage revenue benchmark (reference configuration).
GET/v1/benchmarks/de-bess/customAUTH
Benchmark for your own storage configuration.

Health

GET/v1/health/cross-checksLIVE
Nightly cross-validation of our series against independent sources, with per-series pass/fail.

Documentation

API specification — full request/response shapes for every endpoint.
Data dictionary — every field, unit, and zone code.
Methodology guide — where each series comes from and how derived values are computed.

Provenance

Every series is fetched from its primary source (ENTSO-E, GIE, ENTSOG, Elexon, National Gas, JAO, netztransparenz.de, Open-Meteo, FRED) by a background worker and cross-validated nightly against independent references. The current result is served at /v1/health/cross-checks: key that request like any other. Feed-level freshness and completeness are on /status.