PostGIS MCP Server

Instructions

Implementation Reference

• server.ts:1670-1725 (handler)

  Handler function for the 'spatial-join' tool. Parses input using SpatialJoinSchema, sanitizes table and column names, selects appropriate PostGIS spatial predicate based on join_type, executes a JOIN query between two tables, and returns results with GeoJSON geometries.

  case "spatial-join": {
    const {
      table1,
      table2,
      join_type,
      geometry_column1,
      geometry_column2,
      limit,
    } = SpatialJoinSchema.parse(args);
  
    const sanitizedTable1 = table1.replace(/[^a-zA-Z0-9_]/g, "");
    const sanitizedTable2 = table2.replace(/[^a-zA-Z0-9_]/g, "");
    const sanitizedGeomCol1 = geometry_column1 || "geom";
    const sanitizedGeomCol2 = geometry_column2 || "geom";
  
    const spatialPredicate = {
      intersects: "ST_Intersects",
      within: "ST_Within",
      contains: "ST_Contains",
      touches: "ST_Touches",
    }[join_type];
  
    const result = await client.query(
      `
      SELECT 
        t1.*,
        t2.*,
        ST_AsGeoJSON(t1.${sanitizedGeomCol1}) as t1_geometry,
        ST_AsGeoJSON(t2.${sanitizedGeomCol2}) as t2_geometry
      FROM ${sanitizedTable1} t1
      JOIN ${sanitizedTable2} t2 ON ${spatialPredicate}(t1.${sanitizedGeomCol1}, t2.${sanitizedGeomCol2})
      LIMIT $1;
    `,
      [limit]
    );
  
    return {
      content: [
        {
          type: "text",
          text: JSON.stringify(
            {
              table1: sanitizedTable1,
              table2: sanitizedTable2,
              join_type: join_type,
              spatial_predicate: spatialPredicate,
              results_count: result.rows.length,
              results: result.rows,
            },
            null,
            2
          ),
        },
      ],
    };
  }

• server.ts:106-113 (schema)

  Zod schema defining the input parameters for the spatial-join tool, including two tables, join type, optional geometry columns, and result limit.

  const SpatialJoinSchema = z.object({
    table1: z.string(),
    table2: z.string(),
    join_type: z.enum(["intersects", "within", "contains", "touches"]),
    geometry_column1: z.string().optional().default("geom"),
    geometry_column2: z.string().optional().default("geom"),
    limit: z.number().optional().default(100),
  });

• server.ts:873-900 (registration)

  Registration of the 'spatial-join' tool in the ListToolsRequestSchema handler, providing name, description, and input schema matching SpatialJoinSchema.

    name: "spatial-join",
    description: "İki tablo arasında mekansal join işlemi yap",
    inputSchema: {
      type: "object",
      properties: {
        table1: { type: "string", description: "Birinci tablo adı" },
        table2: { type: "string", description: "İkinci tablo adı" },
        join_type: {
          type: "string",
          enum: ["intersects", "within", "contains", "touches"],
          description: "Join tipi",
        },
        geometry_column1: {
          type: "string",
          description: "Tablo1 geometri kolonu (varsayılan: geom)",
        },
        geometry_column2: {
          type: "string",
          description: "Tablo2 geometri kolonu (varsayılan: geom)",
        },
        limit: {
          type: "number",
          description: "Sonuç limiti (varsayılan: 100)",
        },
      },
      required: ["table1", "table2", "join_type"],
    },
  },