QGISMCP

Instructions

Implementation Reference

• qgis_mcp_plugin/qgis_mcp_plugin.py:241-260 (handler)

  Core handler function that creates a QgsVectorLayer from the given path, validates it, adds it to the QGIS project, and returns layer information including ID, name, type, and feature count.

  def add_vector_layer(self, path, name=None, provider="ogr", **kwargs):
      """Add a vector layer to the project"""
      if not name:
          name = os.path.basename(path)
          
      # Create the layer
      layer = QgsVectorLayer(path, name, provider)
      
      if not layer.isValid():
          raise Exception(f"Layer is not valid: {path}")
      
      # Add to project
      QgsProject.instance().addMapLayer(layer)
      
      return {
          "id": layer.id(),
          "name": layer.name(),
          "type": self._get_layer_type(layer),
          "feature_count": layer.featureCount()
      }

• qgis_mcp_plugin/qgis_mcp_plugin.py:133-149 (registration)

  Registers the add_vector_layer method as a handler for socket commands in the QgisMCPServer's execute_command method.

  handlers = {
      "ping": self.ping,
      "get_qgis_info": self.get_qgis_info,
      "load_project": self.load_project,
      "get_project_info": self.get_project_info,
      "execute_code": self.execute_code,
      "add_vector_layer": self.add_vector_layer,
      "add_raster_layer": self.add_raster_layer,
      "get_layers": self.get_layers,
      "remove_layer": self.remove_layer,
      "zoom_to_layer": self.zoom_to_layer,
      "get_layer_features": self.get_layer_features,
      "execute_processing": self.execute_processing,
      "save_project": self.save_project,
      "render_map": self.render_map,
      "create_new_project": self.create_new_project,
  }

• src/qgis_mcp/qgis_mcp_server.py:182-189 (handler)

  MCP tool handler decorated with @mcp.tool(). Proxies the call to the QGIS plugin server via socket using get_qgis_connection().send_command, providing input schema via type hints and docstring.

  def add_vector_layer(ctx: Context, path: str, provider: str = "ogr", name: str = None) -> str:
      """Add a vector layer to the project."""
      qgis = get_qgis_connection()
      params = {"path": path, "provider": provider}
      if name:
          params["name"] = name
      result = qgis.send_command("add_vector_layer", params)
      return json.dumps(result, indent=2)