Geocoding

{
  "geocoding": {
    "attribution": "© TopoExport, © OpenStreetMap contributors, © OpenAddresses, Who's On First, GeoNames",
    "query": { "text": "Tour Eiffel", "size": 10 }
  },
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "geometry": { "type": "Point", "coordinates": [2.2945, 48.8584] },
      "properties": {
        "gid": "openstreetmap:venue:way/5013364",
        "layer": "venue",
        "source": "openstreetmap",
        "name": "Tour Eiffel",
        "label": "Tour Eiffel, Paris, France",
        "locality": "Paris",
        "region": "Paris",
        "country": "France",
        "country_a": "FRA",
        "confidence": 1
      }
    }
  ],
  "bbox": [2.2945, 48.8584, 2.2945, 48.8584]
}

const KEY = import.meta.env.VITE_TOPOEXPORT_API_KEY;

map.on("click", async (event) => {
  const params = new URLSearchParams({
    "point.lat": String(event.lngLat.lat),
    "point.lon": String(event.lngLat.lng),
    layers: "address,street,venue",
    size: "1",
    key: KEY,
  });
  const response = await fetch(`https://geocode.topoexport.com/v1/geocode/reverse?${params}`);
  if (!response.ok) return;
  const [nearest] = (await response.json()).features;
  if (nearest) {
    // properties.distance: km between the clicked point and the result
    showAddress(nearest.properties.label, nearest.properties.distance);
  }
});

const params = new URLSearchParams({
  address: form.street.value, // house number and street, e.g. "5 avenue Anatole France"
  postalcode: form.postcode.value,
  locality: form.city.value,
  country: "FR",
  size: "1",
  key: KEY,
});
const response = await fetch(`https://geocode.topoexport.com/v1/geocode/structured?${params}`);
const [match] = (await response.json()).features;
// match.properties.confidence: from 0 to 1, low values mean only part of the address matched

// gids saved earlier, e.g. "openstreetmap:venue:way/5013364"
const ids = savedPlaces.map((place) => place.gid);
const params = new URLSearchParams({ ids: ids.join(","), key: KEY });
const { features } = await (await fetch(`https://geocode.topoexport.com/v1/geocode/place?${params}`)).json();

const params = new URLSearchParams({
  "point.lat": "48.8584",
  "point.lon": "2.2945",
  layers: "venue",
  size: "20",
  key: KEY,
});
const { features } = await (await fetch(`https://geocode.topoexport.com/v1/geocode/nearby?${params}`)).json();
for (const place of features) {
  console.log(place.properties.name, `${place.properties.distance} km`);
}

const KEY = import.meta.env.VITE_TOPOEXPORT_API_KEY;
let controller;
let timer;

input.addEventListener("input", () => {
  clearTimeout(timer);
  timer = setTimeout(async () => {
    controller?.abort();
    controller = new AbortController();
    const params = new URLSearchParams({ text: input.value, size: "5", key: KEY });
    try {
      const response = await fetch(`https://geocode.topoexport.com/v1/geocode/autocomplete?${params}`, {
        signal: controller.signal,
      });
      if (!response.ok) return;
      const { features } = await response.json();
      render(features.map((f) => ({ label: f.properties.label, lonLat: f.geometry.coordinates })));
    } catch (error) {
      if (error.name !== "AbortError") throw error;
    }
  }, 250);
});