find_cheapest_fuel
Read-onlyIdempotent
Returns the cheapest stations for one fuel grade near a place or coordinate: price per litre, brand, address, distance, open state. Use when the user asks where to fill up or what fuel costs. Do NOT use for charging an electric car (call find_charging_station), price history, or traffic (call check_autobahn_traffic). Radius ≤ 25 km, at most 10 stations. For a brand, a name, open now or at a named time, or nearest-first, call find_fuel_station. Each line names the age of its price and opening-hours claim. Prices are consumer information only; the attribution line and MTS-K note must be shown.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| lat | No | Latitude in WGS 84, e.g. 48.137. Use with lon when the caller already holds coordinates; otherwise use place. | |
| lon | No | Longitude in WGS 84, e.g. 11.576. Use with lat; otherwise use place. | |
| fuel | No | Fuel grade: "e5" (Super E5), "e10" (Super E10, the standard German petrol) or "diesel" — LPG/Autogas and CNG are not held by any source here: say so, never substitute a petrol grade. Default "e10". Pass the grade the person named — a diesel driver is not helped by a petrol price. | e10 |
| limit | No | How many stations to return, cheapest first (1–10, default 5). The provider's terms cap it at 10. | |
| place | No | Where to look, as free text: a city ("München", "Munich"), a district or Kreis ("Kreis Fulda"), a Bundesland, a station or stop ("Hamburg Hbf"), a motorway junction ("AK Neufahrn"), or a street address with a house number ("Bahnhofstraße 12, 36037 Fulda"). A motorway number alone ("A7") resolves to the road, which has no single point — name a town or junction on it instead. Use this instead of coordinates whenever the person named a place. An address needs its town or postcode — a street and a number alone exist in many towns. A place or lat+lon is required (unless the tool names another way in, such as a road): when the person named neither, ask them for a town, a postcode or their position before calling. Given both, the answer is about lat+lon with the place as its label, and is refused only when the two lie further apart than the search reaches. | |
| language | No | Set this on every call to the language the person is writing in: "en" if they wrote English, "de" if they wrote German. Do not leave it out: it defaults to German ("de"), which is only the fallback when the language is genuinely unclear, so an English question sent without it is answered in German — a wrong answer. Place names, station names and road numbers are never translated in either language; in English the German term is kept in parentheses so the person recognises it on signs and in local apps. | de |
| radius_km | No | Search radius around the place in kilometres (1–25, default 5). The provider's terms cap it at 25 km — a larger circle is a dataset request, not a consumer question. |