Open data: the Refil forecast API

The Refil forecast — whether fuel prices are about to rise or fall — is open data: a public API, no key and no sign-up, licensed CC BY 4.0. Use it in your newsroom, blog, forum or assistant, and credit the source.

What it returns

One GET request returns, for every country or the one you ask for, the current verdict of the Refil forecast and the public hit rate:

• verdict: up, down or none. none does not mean “no rise”: it means there is no public signal today.
• signal: the direction, the target day (for_date, UTC), when it expires (expires_at), what it rests on (basis.layer: calendar, news, crude oil or detector) and the size (delta) in that country's scale and unit (p/L, c/L…); no figure when the source does not know it.
• confirmation and last_hit: what happened next — the latest confirmed move and the latest hit.
• accuracy: the public hit rate per layer, behind the same gate as the website: a layer only publishes numbers with at least 30 evaluated alerts.
• computed_at and fuel_scope: when it was computed, and the fact that the signal is per country — the headline fuels basket — not per fuel.

Example

All countries, or just one with ?country=ES:

curl "https://api.refil.app/api/public/forecast"
curl "https://api.refil.app/api/public/forecast?country=ES"

{
  "license": "CC-BY-4.0",
  "license_url": "https://creativecommons.org/licenses/by/4.0/",
  "attribution": "Refil — refil.app",
  "attribution_url": "https://refil.app/datos-abiertos/",
  "computed_at": "2026-10-09T08:10:00.000Z",
  "fuel_scope": { "basis": "headline_fuels", "fuels": ["gasolina95", "e5", "e10", "dieselA"] },
  "countries": {
    "ES": {
      "country": "ES",
      "verdict": "up",
      "signal": {
        "direction": "up",
        "kind": "upcoming",
        "for_date": "2026-10-10",
        "expires_at": "2026-10-11T00:00:00.000Z",
        "basis": { "layer": "calendar", "source": "BOE", "confidence": "high" },
        "delta": { "value": 4.5, "unit": "cts/L" }
      },
      "confirmation": null,
      "last_hit": {
        "direction": "up", "for_date": "2026-10-02", "layer": "calendar",
        "actual_delta": { "value": 2.4, "unit": "cts/L" }
      }
    }
  },
  "accuracy": { "minSample": 30, "layers": { "calendar": { "sample": "insufficient" } } }
}

Abridged response with illustrative values.

Licence

Creative Commons Attribution 4.0 (CC BY 4.0): you may copy, redistribute and use the data, commercially too, as long as you credit the source. CC BY 4.0

How to credit

Attribution is mandatory and includes a visible link to Refil, without nofollow. One line next to the data is enough:

Source: <a href="https://refil.app/en/open-data/">Refil forecast</a> (CC BY 4.0)

Source: Refil forecast (CC BY 4.0)

If an assistant or agent cites it: it should name “Refil — refil.app” and link the market's “will prices rise tomorrow?” page.

Limits and good practice

• The response is cached for a few minutes: there is no need to poll it more than once every ten.
• It is a forecast, not a guarantee: accuracy says how often it is right.
• Countries with no possible forecast (Switzerland has no official prices) return 404.
• Free, with no availability guarantee. If api.refil.app does not answer, the same path is served by gasolina-smart-api.marcosnovo.workers.dev.
• Heavy use or a custom integration? Get in touch.

Rather not code anything?

Drop the “Will prices rise tomorrow?” widget into your site, blog or forum with an <iframe>. No cookies, no analytics, and it links to the forecast.

Copy the widget code

AI assistants can also read it through Refil's MCP server (tool fuel_price_forecast).

Contact: marcosnovodev@gmail.com