get_layers

Instructions

Implementation Reference

• src/qgis_mcp/qgis_mcp_server.py:201-206 (handler)

  MCP tool handler for 'get_layers' that connects to QGIS socket server and forwards the command, returning JSON response.

  @mcp.tool()
  def get_layers(ctx: Context) -> str:
      """Retrieve all layers in the current project."""
      qgis = get_qgis_connection()
      result = qgis.send_command("get_layers")
      return json.dumps(result, indent=2)

• qgis_mcp_plugin/qgis_mcp_plugin.py:284-311 (handler)

  Core QGIS plugin handler that implements get_layers by iterating over project layers and collecting detailed information.

  def get_layers(self, **kwargs):
      """Get all layers in the project"""
      project = QgsProject.instance()
      layers = []
      
      for layer_id, layer in project.mapLayers().items():
          layer_info = {
              "id": layer_id,
              "name": layer.name(),
              "type": self._get_layer_type(layer),
              "visible": project.layerTreeRoot().findLayer(layer_id).isVisible()
          }
          
          # Add type-specific information
          if layer.type() == QgsMapLayer.VectorLayer:
              layer_info.update({
                  "feature_count": layer.featureCount(),
                  "geometry_type": layer.geometryType()
              })
          elif layer.type() == QgsMapLayer.RasterLayer:
              layer_info.update({
                  "width": layer.width(),
                  "height": layer.height()
              })
              
          layers.append(layer_info)
      
      return layers

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

  Registration of command handlers in QGIS plugin server, including 'get_layers' mapped to self.get_layers 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:79-108 (helper)

  Helper function to manage persistent socket connection to the QGIS MCP plugin server.

  def get_qgis_connection():
      """Get or create a persistent Qgis connection"""
      global _qgis_connection
      
      # If we have an existing connection, check if it's still valid
      if _qgis_connection is not None:
          # Test if the connection is still alive with a simple ping
          try:
              # Just try to send a small message to check if the socket is still connected
              _qgis_connection.sock.sendall(b'')
              return _qgis_connection
          except Exception as e:
              # Connection is dead, close it and create a new one
              logger.warning(f"Existing connection is no longer valid: {str(e)}")
              try:
                  _qgis_connection.disconnect()
              except Exception:
                  pass
              _qgis_connection = None
      
      # Create a new connection if needed
      if _qgis_connection is None:
          _qgis_connection = QgisMCPServer(host="localhost", port=9876)
          if not _qgis_connection.connect():
              logger.error("Failed to connect to Qgis")
              _qgis_connection = None
              raise Exception("Could not connect to Qgis. Make sure the Qgis plugin is running.")
          logger.info("Created new persistent connection to Qgis")
      
      return _qgis_connection