GIS MCP Server

Instructions

Implementation Reference

• src/gis_mcp/rasterio_functions.py:1251-1302 (handler)

  The handler function that implements the core logic of weighted_band_sum: reads a multi-band raster, applies weights to each band, computes the sum, and writes the result to a new single-band raster file.

  def weighted_band_sum(
      source: str,
      weights: List[float],
      destination: str
  ) -> Dict[str, Any]:
      """
      Compute a weighted sum of all bands in a raster using specified weights.
  
      Parameters:
      - source:      Path to the input multi-band raster file.
      - weights:     List of weights (must match number of bands and sum to 1).
      - destination: Path to save the output single-band raster.
      """
      try:
          import os
          import numpy as np
          import rasterio
  
          src_path = os.path.expanduser(source.replace("`", ""))
          dst_path = os.path.expanduser(destination.replace("`", ""))
  
          with rasterio.open(src_path) as src:
              count = src.count
              if len(weights) != count:
                  raise ValueError(f"Number of weights ({len(weights)}) does not match number of bands ({count}).")
  
              if not np.isclose(sum(weights), 1.0, atol=1e-6):
                  raise ValueError("Sum of weights must be 1.0.")
  
              weighted = np.zeros((src.height, src.width), dtype="float32")
  
              for i in range(1, count + 1):
                  band = src.read(i).astype("float32")
                  weighted += weights[i - 1] * band
  
              profile = src.profile.copy()
              profile.update(dtype="float32", count=1)
  
          os.makedirs(os.path.dirname(dst_path) or ".", exist_ok=True)
  
          with rasterio.open(dst_path, "w", **profile) as dst:
              dst.write(weighted, 1)
  
          return {
              "status": "success",
              "destination": str(dst_path),
              "message": f"Weighted band sum computed and saved to '{dst_path}'."
          }
  
      except Exception as e:
          raise ValueError(f"Failed to compute weighted sum: {e}")

• src/gis_mcp/rasterio_functions.py:11-35 (registration)

  Resource function that lists 'weighted_band_sum' among available rasterio operations, indicating its registration in the MCP toolset.

  @gis_mcp.resource("gis://operation/rasterio")
  def get_rasterio_operations() -> Dict[str, List[str]]:
      """List available rasterio operations."""
      return {
          "operations": [
              "metadata_raster",
              "get_raster_crs",
              "clip_raster_with_shapefile",
              "resample_raster",
              "reproject_raster",
              "weighted_band_sum",
              "concat_bands",
              "raster_algebra",
              "compute_ndvi",
              "raster_histogram",
              "tile_raster",
              "raster_band_statistics",
              "extract_band",
              "zonal_statistics",
              "reclassify_raster",
              "focal_statistics",
              "hillshade",
              "write_raster"
          ]
      }

• src/gis_mcp/mcp.py:1-6 (registration)

  Creates the FastMCP instance 'gis_mcp' to which tools like weighted_band_sum are registered via decorators.

  # MCP imports using the new SDK patterns
  from fastmcp import FastMCP
  
  
  gis_mcp = FastMCP("GIS MCP")