PostGIS MCP Server

Instructions

Implementation Reference

• server.js:298-327 (handler)

  The main handler for the 'find-nearby' tool. It parses input using FindNearbySchema, sanitizes the table name, executes a PostGIS query using ST_DWithin to find nearby geometries within distance_km and ST_Distance to compute distances, orders by distance, limits results, and returns JSON of the rows.

      case "find-nearby": {
          const { latitude, longitude, distance_km, table_name, limit } = FindNearbySchema.parse(args);
          // Tablo adını sanitize et (basit güvenlik)
          const sanitizedTableName = table_name.replace(/[^a-zA-Z0-9_]/g, '');
          const result = yield client.query(`
    SELECT 
      *,
      ST_AsGeoJSON(geom) as geometry,
      ST_Distance(
        geom, 
        ST_SetSRID(ST_MakePoint($1, $2), 4326)::geography
      ) / 1000 as distance_km
    FROM ${sanitizedTableName}
    WHERE ST_DWithin(
      geom, 
      ST_SetSRID(ST_MakePoint($1, $2), 4326)::geography, 
      $3
    )
    ORDER BY distance_km
    LIMIT $4;
  `, [longitude, latitude, distance_km * 1000, limit]);
          return {
              content: [
                  {
                      type: "text",
                      text: JSON.stringify(result.rows, null, 2),
                  },
              ],
          };
      }

• server.js:33-39 (schema)

  Zod validation schema for the input parameters of the 'find-nearby' tool.

  const FindNearbySchema = zod_1.z.object({
      latitude: zod_1.z.number(),
      longitude: zod_1.z.number(),
      distance_km: zod_1.z.number(),
      table_name: zod_1.z.string(),
      limit: zod_1.z.number().optional().default(10),
  });

• server.js:118-132 (registration)

  Tool registration entry in the ListTools handler, defining the name, description, and input schema for 'find-nearby'.

  {
      name: "find-nearby",
      description: "Belirli bir noktanın çevresindeki özellikleri bul",
      inputSchema: {
          type: "object",
          properties: {
              latitude: { type: "number", description: "Merkez nokta enlem" },
              longitude: { type: "number", description: "Merkez nokta boylam" },
              distance_km: { type: "number", description: "Arama mesafesi (km)" },
              table_name: { type: "string", description: "Aranacak tablo adı" },
              limit: { type: "number", description: "Maksimum sonuç sayısı (varsayılan: 10)" },
          },
          required: ["latitude", "longitude", "distance_km", "table_name"],
      },
  },