PostGIS MCP Server

Instructions

Implementation Reference

• server.js:328-351 (handler)

  Implements the create-buffer tool: parses input using CreateBufferSchema, queries PostGIS with ST_Buffer to create a buffer around the input geometry, returns buffer in WKT and GeoJSON formats along with area.

      case "create-buffer": {
          const { geometry_wkt, distance_meters } = CreateBufferSchema.parse(args);
          const result = yield client.query(`
    SELECT 
      ST_AsText(ST_Buffer(ST_GeomFromText($1), $2)) as buffer_wkt,
      ST_AsGeoJSON(ST_Buffer(ST_GeomFromText($1), $2)) as buffer_geojson,
      ST_Area(ST_Buffer(ST_GeomFromText($1), $2)) as buffer_area
  `, [geometry_wkt, distance_meters]);
          const response = {
              original_geometry: geometry_wkt,
              buffer_distance_meters: distance_meters,
              buffer_wkt: result.rows[0].buffer_wkt,
              buffer_geojson: JSON.parse(result.rows[0].buffer_geojson),
              buffer_area: parseFloat(result.rows[0].buffer_area),
          };
          return {
              content: [
                  {
                      type: "text",
                      text: JSON.stringify(response, null, 2),
                  },
              ],
          };
      }

• server.js:40-43 (schema)

  Zod schema defining the input parameters for create-buffer: geometry_wkt (string) and distance_meters (number). Used for validation in the handler.

  const CreateBufferSchema = zod_1.z.object({
      geometry_wkt: zod_1.z.string(),
      distance_meters: zod_1.z.number(),
  });

• server.js:133-144 (registration)

  Registers the create-buffer tool in the ListTools response with name, description, and inputSchema matching the Zod schema.

  {
      name: "create-buffer",
      description: "Geometri etrafında buffer oluştur",
      inputSchema: {
          type: "object",
          properties: {
              geometry_wkt: { type: "string", description: "WKT formatında geometri" },
              distance_meters: { type: "number", description: "Buffer mesafesi (metre)" },
          },
          required: ["geometry_wkt", "distance_meters"],
      },
  },