MCP Jupyter Server

Instructions

Implementation Reference

• src/jupyter-handler.js:247-267 (handler)

  The main handler function for the 'move_cell' tool. It reads the Jupyter notebook JSON, validates indices, moves the cell by splicing the cells array, writes the updated notebook back to disk, and returns a success message.

  async moveCell(notebookPath, fromIndex, toIndex) {
    const notebook = await this.readNotebook(notebookPath);
    this.validateCellIndex(notebook.cells, fromIndex);
    
    if (toIndex < 0 || toIndex >= notebook.cells.length) {
      throw new Error(`Invalid target index ${toIndex}. Must be between 0 and ${notebook.cells.length - 1}`);
    }
    
    const [movedCell] = notebook.cells.splice(fromIndex, 1);
    notebook.cells.splice(toIndex, 0, movedCell);
    await this.writeNotebook(notebookPath, notebook);
    
    return {
      content: [
        {
          type: "text",
          text: `Successfully moved cell from index ${fromIndex} to ${toIndex}`
        }
      ]
    };
  }

• src/index.js:141-162 (schema)

  JSON Schema defining the input parameters for the 'move_cell' tool: notebook_path (string), from_index (integer), to_index (integer). Returned by the ListTools handler.

  {
    name: "move_cell",
    description: "Move a cell from one position to another",
    inputSchema: {
      type: "object",
      properties: {
        notebook_path: {
          type: "string",
          description: "Absolute path to the Jupyter notebook file"
        },
        from_index: {
          type: "integer",
          description: "Current index of the cell"
        },
        to_index: {
          type: "integer",
          description: "Target index for the cell"
        }
      },
      required: ["notebook_path", "from_index", "to_index"]
    }
  },

• src/index.js:355-360 (registration)

  Tool call dispatching/registration in the CallToolRequestSchema handler's switch statement, which routes 'move_cell' calls to JupyterHandler.prototype.moveCell.

  case "move_cell":
    return await this.jupyterHandler.moveCell(
      args.notebook_path,
      args.from_index,
      args.to_index
    );