An API for developers
A free read-only v0 is live and needs no key. What we are still working out is whether the accuracy-labelled forecast is worth paying for, and we would rather ask than guess.
v0 because it may change shape; a breaking change bumps the prefix rather than quietly reshaping a payload your automation parses. Commercial use is still a conversation — tell us what you are building.Call it now
Three read-only endpoints. Attribution is required and travels in every payload. Please cache: the data changes once an hour at most, and the responses say so.
GET /api/v0/zonesEvery zone, its consumer unit and VAT, and whether its outlook publishes — with the accuracy it is entitled to claim.
GET /api/v0/zones/{zone}/pricesToday and tomorrow, hourly, in both EUR/MWh and the zone’s own consumer unit, plus the cheapest contiguous 2, 3 and 4-hour stretches.
tomorrowisnulluntil the day-ahead auction clears, around 13:00 CET — it is not an empty day, it is a day that does not exist yet.GET /api/v0/zones/{zone}/outlookThe cheap/normal/expensive/extreme call per day, its source, and its measured accuracy. A withheld zone returns
published: falsewith the reason, and still returns its settled days — a cleared auction is a fact, not a forecast.
Two routes rather than one with a parameter, deliberately: it lets us see whether anyone actually wants the forecast, which is the only question worth answering before building a paid tier.
The two tiers
Day-ahead prices — free, with attribution
Per-zone hourly and native 15-minute prices for all 24 bidding zones, from the ENTSO-E Transparency Platform. This is a commodity and it is priced like one: free, attributed, rate-limited. It exists to be useful, not to be a business. The v0 endpoints above are this tier.
The accuracy-labelled outlook — the part that is not free anywhere else
A cheap/normal/expensive/extreme call per day, per zone, with the MEASURED accuracy that call is entitled to claim — and nothing at all for a zone that has not earned one. Today 14 of 24 zones clear both bars (AUC ≥ 0.75 on the tails and Spearman ρ ≥ 0.65 across all days); the rest are withheld, and the v0 outlook endpoint withholds exactly the same zones for exactly the same reasons. See what is measured, and what is not.
Tell us what you would build
Especially: which zones, which endpoint, and whether it is for something commercial. That last one is the question we cannot answer from traffic.
In the meantime
Every zone page and every history page is public, uncredentialed and stable. Scraping them is fine — but tell us you are doing it, and we will build you something better than HTML.
There is also an embeddable strip per zone — /zones/SE3/embed — carrying the outlook and the cheapest stretch, no navigation, safe to put in an iframe. It shows exactly what the zone page shows, withheld zones included: there is no parameter that drops the caveat, because an embed that could would be a way to launder a claim through someone else's site.
<iframe src="https://gridcast.cmshq.work/zones/SE3/embed" width="420" height="520" style="border:0" title="gridcast"></iframe>