mcp-swiss

Instructions

Implementation Reference

• src/modules/hiking.ts:264-321 (handler)

  The handler function for 'get_trail_closures_nearby', which converts WGS84 coordinates to LV95 and queries the swisstopo identify endpoint.

  async function handleGetTrailClosuresNearby(
    args: Record<string, unknown>
  ): Promise<string> {
    const lat = Number(args.lat);
    const lon = Number(args.lon);
  
    if (isNaN(lat) || isNaN(lon)) {
      throw new Error("lat and lon must be valid numbers");
    }
    if (lat < 45.0 || lat > 48.0 || lon < 5.5 || lon > 11.0) {
      throw new Error("Coordinates appear to be outside Switzerland (lat 45–48, lon 5.5–11)");
    }
  
    const radius = Math.min(50000, Math.max(1, Number(args.radius) || 10000));
  
    // Convert WGS84 → LV95
    const [e, n] = wgs84ToLv95(lat, lon);
  
    // Build map extent based on radius (approx 1 metre = 1 LV95 unit)
    const extent = `${e - radius},${n - radius},${e + radius},${n + radius}`;
  
    const url = buildUrl(`${BASE}/identify`, {
      layers: `all:${LAYER}`,
      geometry: `${e},${n}`,
      geometryType: "esriGeometryPoint",
      sr: 2056,
      tolerance: radius,
      imageDisplay: "1,1,100",
      mapExtent: extent,
      returnGeometry: false,
    });
  
    const data = await fetchJSON<FindResponse>(url);
    const closures = deduplicate((data.results ?? []).map(slimClosure));
  
    const result = {
      count: closures.length,
      query: {
        lat,
        lon,
        radius_m: radius,
        lv95_e: Math.round(e),
        lv95_n: Math.round(n),
      },
      source: "ASTRA / Schweizer Wanderwege (swisstopo ch.astra.wanderland-sperrungen_umleitungen)",
      closures,
    };
  
    const json = JSON.stringify(result);
    if (json.length > 49000) {
      const trimmed = {
        ...result,
        closures: closures.map((c) => ({ ...c, description: c.description.slice(0, 100) })),
      };
      return JSON.stringify(trimmed);
    }
    return json;
  }

• src/modules/hiking.ts:147-171 (registration)

  The definition and registration of the 'get_trail_closures_nearby' tool including its schema.

  {
    name: "get_trail_closures_nearby",
    description:
      "Find Swiss hiking trail closures and detours near a given GPS coordinate. " +
      "Converts WGS84 coordinates to Swiss LV95 and queries the swisstopo identify endpoint. " +
      "Returns closures within the specified radius.",
    inputSchema: {
      type: "object",
      properties: {
        lat: {
          type: "number",
          description: "Latitude in WGS84 (e.g. 46.9480 for Bern).",
        },
        lon: {
          type: "number",
          description: "Longitude in WGS84 (e.g. 7.4474 for Bern).",
        },
        radius: {
          type: "number",
          description: "Search radius in metres. Default: 10000 (10 km). Max: 50000.",
        },
      },
      required: ["lat", "lon"],
    },
  },