GIS MCP Server

Instructions

Implementation Reference

• src/gis_mcp/rasterio_functions.py:874-916 (handler)

  The core handler function for the 'extract_band' tool. It reads a specific band from the source raster using rasterio, copies the profile, updates the band count to 1, and writes the extracted band to the destination path.

  def extract_band(
      source: str,
      band_index: int,
      destination: str
  ) -> Dict[str, Any]:
      """
      Extract a specific band from a multi-band raster and save it as a single-band GeoTIFF.
  
      Parameters:
      - source:      path or URL of the input raster.
      - band_index:  index of the band to extract (1-based).
      - destination: path to save the extracted band raster.
      """
      try:
          import rasterio
  
          src_path = os.path.expanduser(source.replace("`", ""))
          dst_path = os.path.expanduser(destination.replace("`", ""))
  
          with rasterio.open(src_path) as src:
              if band_index < 1 or band_index > src.count:
                  raise ValueError(f"Band index {band_index} is out of range. This raster has {src.count} bands.")
  
              band = src.read(band_index)
              profile = src.profile.copy()
              profile.update({
                  "count": 1
              })
  
          os.makedirs(os.path.dirname(dst_path) or ".", exist_ok=True)
  
          with rasterio.open(dst_path, "w", **profile) as dst:
              dst.write(band, 1)
  
          return {
              "status": "success",
              "destination": str(dst_path),
              "message": f"Band {band_index} extracted and saved to '{dst_path}'."
          }
  
      except Exception as e:
          raise ValueError(f"Failed to extract band: {e}")

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

  The 'extract_band' tool is registered/listed in the rasterio operations resource, which provides a list of available rasterio tools.

  @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"
          ]
      }