Macrostrat MCP Server

Instructions

Implementation Reference

• src/index.ts:1092-1120 (handler)

  The handler function that performs the core logic: converts latitude/longitude and zoom to tile coordinates (x, y, z) using Web Mercator projection formulas.

  async (request) => {
    const { lat, lng, zoom } = request;
    
    // Proper web mercator tile coordinate calculation (same as MapKit)
    const n = Math.pow(2, zoom);
    const x = Math.floor((lng + 180) / 360 * n);
    
    // Convert latitude to radians
    const lat_rad = lat * Math.PI / 180;
    // Web mercator y calculation
    const y = Math.floor((1 - Math.asinh(Math.tan(lat_rad)) / Math.PI) / 2 * n);
    
    const data = {
      x,
      y,
      z: zoom,
      lat,
      lng,
      zoom,
      note: "Use these x,y coordinates with the map-tiles tool"
    };
  
    return {
      content: [{
        type: "text" as const,
        text: JSON.stringify(data, null, 2)
      }]
    };
  }

• src/index.ts:1083-1091 (schema)

  Zod input schema defining parameters: lat, lng, zoom with validation and descriptions.

  {
    title: "Latitude/Longitude to Tile",
    description: "Convert latitude/longitude coordinates to map tile coordinates (x, y) for a given zoom level. Uses the same web mercator projection as MapKit.",
    inputSchema: {
      lat: z.number().min(-90).max(90).describe("Latitude in decimal degrees (-90 to 90)"),
      lng: z.number().min(-180).max(180).describe("Longitude in decimal degrees (-180 to 180)"),
      zoom: z.number().int().min(0).max(18).describe("Zoom level (0-18)"),
    }
  },

• src/index.ts:1081-1121 (registration)

  Registration of the 'lat-lng-to-tile' tool with MCP server, including schema and handler.

  server.registerTool(
    "lat-lng-to-tile",
    {
      title: "Latitude/Longitude to Tile",
      description: "Convert latitude/longitude coordinates to map tile coordinates (x, y) for a given zoom level. Uses the same web mercator projection as MapKit.",
      inputSchema: {
        lat: z.number().min(-90).max(90).describe("Latitude in decimal degrees (-90 to 90)"),
        lng: z.number().min(-180).max(180).describe("Longitude in decimal degrees (-180 to 180)"),
        zoom: z.number().int().min(0).max(18).describe("Zoom level (0-18)"),
      }
    },
    async (request) => {
      const { lat, lng, zoom } = request;
      
      // Proper web mercator tile coordinate calculation (same as MapKit)
      const n = Math.pow(2, zoom);
      const x = Math.floor((lng + 180) / 360 * n);
      
      // Convert latitude to radians
      const lat_rad = lat * Math.PI / 180;
      // Web mercator y calculation
      const y = Math.floor((1 - Math.asinh(Math.tan(lat_rad)) / Math.PI) / 2 * n);
      
      const data = {
        x,
        y,
        z: zoom,
        lat,
        lng,
        zoom,
        note: "Use these x,y coordinates with the map-tiles tool"
      };
  
      return {
        content: [{
          type: "text" as const,
          text: JSON.stringify(data, null, 2)
        }]
      };
    }
  );