Excel MCP Server

Instructions

Create a chart from Excel data and return as an image.

Args:
    file_path: Path to the Excel file
    x_column: Column to use for x-axis
    y_column: Column to use for y-axis
    chart_type: Type of chart ('line', 'bar', 'scatter', 'hist')
    sheet_name: Name of the sheet to chart (for Excel files)
    
Returns:
    Chart as image

Implementation Reference

• mcp_excel_server/server.py:478-555 (handler)

  Implementation of the 'export_chart' tool handler. Decorated with @mcp.tool(), reads data from various file formats (Excel, CSV, etc.), creates charts using matplotlib/seaborn (line, bar, scatter, hist), and returns a PNG image or error image.

  @mcp.tool()
  def export_chart(file_path: str, x_column: str, y_column: str, 
                 chart_type: str = "line", sheet_name: Optional[str] = None) -> Image:
      """
      Create a chart from Excel data and return as an image.
      
      Args:
          file_path: Path to the Excel file
          x_column: Column to use for x-axis
          y_column: Column to use for y-axis
          chart_type: Type of chart ('line', 'bar', 'scatter', 'hist')
          sheet_name: Name of the sheet to chart (for Excel files)
          
      Returns:
          Chart as image
      """
      import matplotlib.pyplot as plt
      import seaborn as sns
      
      try:
          # Read file
          _, ext = os.path.splitext(file_path)
          ext = ext.lower()
          
          read_params = {}
          if ext in ['.xlsx', '.xls', '.xlsm'] and sheet_name is not None:
              read_params["sheet_name"] = sheet_name
              
          if ext in ['.xlsx', '.xls', '.xlsm']:
              df = pd.read_excel(file_path, **read_params)
          elif ext == '.csv':
              df = pd.read_csv(file_path)
          elif ext == '.tsv':
              df = pd.read_csv(file_path, sep='\t')
          elif ext == '.json':
              df = pd.read_json(file_path)
          else:
              raise ValueError(f"Unsupported file extension: {ext}")
          
          # Create chart
          plt.figure(figsize=(10, 6))
          
          if chart_type == "line":
              sns.lineplot(data=df, x=x_column, y=y_column)
          elif chart_type == "bar":
              sns.barplot(data=df, x=x_column, y=y_column)
          elif chart_type == "scatter":
              sns.scatterplot(data=df, x=x_column, y=y_column)
          elif chart_type == "hist":
              df[y_column].hist()
              plt.xlabel(y_column)
          else:
              raise ValueError(f"Unsupported chart type: {chart_type}")
          
          plt.title(f"{chart_type.capitalize()} Chart: {y_column} by {x_column}")
          plt.tight_layout()
          
          # Save to bytes buffer
          buf = io.BytesIO()
          plt.savefig(buf, format='png')
          buf.seek(0)
          
          # Convert to Image
          plt.close()
          return Image(data=buf.getvalue(), format="png")
      except Exception as e:
          # Return error image
          plt.figure(figsize=(8, 2))
          plt.text(0.5, 0.5, f"Error creating chart: {str(e)}", 
                   horizontalalignment='center', fontsize=12, color='red')
          plt.axis('off')
          
          buf = io.BytesIO()
          plt.savefig(buf, format='png')
          buf.seek(0)
          plt.close()
          
          return Image(data=buf.getvalue(), format="png")