VisiData MCP Server

Instructions

Implementation Reference

• src/visidata_mcp/server.py:73-118 (handler)

  The load_data tool handler that loads data from files (CSV, JSON, Excel, TSV) using pandas and returns basic dataset information including filename, row count, column count, column names, column types, and file size.

  @mcp.tool()
  def load_data(file_path: str, file_type: Optional[str] = None) -> str:
      """
      Load data from a file using VisiData.
      
      Args:
          file_path: Path to the data file
          file_type: Optional file type hint (csv, json, xlsx, etc.)
      
      Returns:
          String representation of the loaded data structure
      """
      try:
          # Use pandas as a reliable fallback for common formats
          import pandas as pd
          from pathlib import Path
          
          file_extension = Path(file_path).suffix.lower()
          
          # Load with pandas first for reliability
          if file_extension == '.csv':
              df = pd.read_csv(file_path)
          elif file_extension == '.json':
              df = pd.read_json(file_path)
          elif file_extension in ['.xlsx', '.xls']:
              df = pd.read_excel(file_path)
          elif file_extension == '.tsv':
              df = pd.read_csv(file_path, sep='\t')
          else:
              # Try CSV as default
              df = pd.read_csv(file_path)
          
          # Get basic information about the dataset
          info = {
              "filename": Path(file_path).name,
              "rows": len(df),
              "columns": len(df.columns),
              "column_names": list(df.columns)[:10],  # First 10 columns
              "column_types": [str(df[col].dtype) for col in df.columns[:10]],
              "file_size": Path(file_path).stat().st_size if Path(file_path).exists() else 0
          }
          
          return json.dumps(info, indent=2)
          
      except Exception as e:
          return f"Error loading data: {str(e)}\n{traceback.format_exc()}"

• src/visidata_mcp/server.py:73-74 (registration)

  The @mcp.tool() decorator registers the load_data function as an MCP tool with the server.

  @mcp.tool()
  def load_data(file_path: str, file_type: Optional[str] = None) -> str: