Excel Tool

December 1, 2025 · View on GitHub

Excel (xlsx) file manipulation tool providing workbook, worksheet, data, formatting, chart, pivot table, formula, and validation operations.

Configuration

Disabled by default - requires explicit enablement:

{
  "mcpServers": {
    "dev-tools": {
      "env": {
        "ENABLE_ADDITIONAL_TOOLS": "excel",
        "EXCEL_FILES_PATH": "/path/to/excel/files"
      }
    }
  }
}

Environment Variables

  • ENABLE_ADDITIONAL_TOOLS - Must include excel to enable this tool
  • EXCEL_FILES_PATH - (Only required when running the server is running in HTTP mode) Allows you to set a base directory for Excel files in HTTP mode (default: ~/.mcp-devtools/excel/)

Transport Modes

  • STDIO mode: Use absolute file paths
  • HTTP mode: Use relative paths from EXCEL_FILES_PATH

Functions

Workbook Operations

create_workbook

Create a new Excel workbook.

Parameters:

  • filepath (required): Path to Excel file
  • options.initial_sheet_name (optional): Initial worksheet name (default: "Sheet1")

Example:

{
  "function": "create_workbook",
  "filepath": "/path/to/workbook.xlsx",
  "options": {
    "initial_sheet_name": "Data"
  }
}

get_workbook_metadata

Retrieve workbook information including sheet names, file size, and data ranges.

Parameters:

  • filepath (required): Path to Excel file
  • options.include_ranges (optional): Include data ranges for each sheet (default: false)

Worksheet Management

create_worksheet

Add a new worksheet to the workbook.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Name for new worksheet

copy_worksheet

Clone an existing worksheet.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Source worksheet name
  • options.target_name (required): Name for copied worksheet

delete_worksheet

Remove a worksheet from the workbook.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Worksheet name to delete

Note: Cannot delete the last remaining worksheet.

rename_worksheet

Rename an existing worksheet.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Current worksheet name
  • options.new_name (required): New worksheet name

Data Operations

read_data

Read data from a cell range.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Worksheet name
  • options.start_cell (optional): Starting cell (e.g., "A1")
  • options.end_cell (optional): Ending cell (e.g., "D10")

Example:

{
  "function": "read_data",
  "filepath": "/path/to/workbook.xlsx",
  "sheet_name": "Sheet1",
  "options": {
    "start_cell": "A1",
    "end_cell": "C10"
  }
}

read_all_data

Export all data from one or more sheets in AI-agent-friendly format (CSV, TSV, or JSON).

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (optional): Single sheet to read
  • options.sheet_names (optional): Array of sheet names to read
  • options.format (optional): Output format - "csv" (default, token-optimised), "tsv", or "json"
  • options.max_rows (optional): Limit rows per sheet to prevent token overflow
  • options.offset (optional): Skip first N rows before reading (for pagination, default: 0)

Note: If neither sheet_name nor options.sheet_names is specified, reads all sheets. All rows are padded to the same length with empty strings for consistency.

Example - Read all sheets as CSV:

{
  "function": "read_all_data",
  "filepath": "/path/to/workbook.xlsx",
  "options": {
    "format": "csv"
  }
}

Example - Read specific sheets with row limit:

{
  "function": "read_all_data",
  "filepath": "/path/to/large-report.xlsx",
  "options": {
    "sheet_names": ["Sales", "Expenses"],
    "format": "tsv",
    "max_rows": 100
  }
}

Response format:

{
  "sheets": [
    {
      "sheet_name": "Sales",
      "format": "csv",
      "data": "Month,Revenue,Tax\nJan,5000,1000\nFeb,6500,1300",
      "dimensions": {
        "total_rows": 3,
        "returned_rows": 3,
        "start_row": 1,
        "end_row": 3,
        "remaining_rows": 0,
        "columns": 3
      }
    }
  ]
}

write_data

Write data to cells. Formulas can be included directly in the data array.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Worksheet name
  • options.start_cell (required): Starting cell for data
  • options.data (required): 2D array of data to write

Formula Support: Any string value starting with = is automatically treated as a formula. Formulas are validated for safety and calculated for Apple Numbers compatibility.

Example with formulas:

{
  "function": "write_data",
  "filepath": "/path/to/workbook.xlsx",
  "sheet_name": "Sheet1",
  "options": {
    "start_cell": "A1",
    "data": [
      ["Item", "Price", "Quantity", "Total"],
      ["Apples", 1.50, 10, "=B2*C2"],
      ["Oranges", 2.00, 5, "=B3*C3"],
      ["", "", "Grand Total:", "=SUM(D2:D3)"]
    ]
  }
}

Basic example:

{
  "function": "write_data",
  "filepath": "/path/to/workbook.xlsx",
  "sheet_name": "Sheet1",
  "options": {
    "start_cell": "A1",
    "data": [
      ["Name", "Age", "Salary"],
      ["Alice", 30, 75000],
      ["Bob", 25, 65000]
    ]
  }
}

read_data_with_metadata

Read data with validation rules and metadata.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Worksheet name
  • options.start_cell (optional): Starting cell
  • options.end_cell (optional): Ending cell

Returns cell data with validation information including dropdown lists and validation rules.

Formatting

format_range

Apply formatting to cell ranges.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Worksheet name
  • options.range (required): Cell range (e.g., "A1:D10")
  • options.font (optional): Font properties (bold, italic, size, colour, family)
  • options.fill (optional): Fill properties (colour, pattern)
  • options.borders (optional): Border properties (style, colour, sides)
  • options.alignment (optional): Alignment properties (horizontal, vertical, wrap_text)
  • options.number_format (optional): Number format string (e.g., "£#,##0.00")
  • options.conditional_format (optional): Conditional formatting rules

Style Merging: When applying formatting to cells that already have styles, the new properties are merged with existing ones. This means you can apply fill and font in one call, then add borders in another call, and both will be preserved.

Colour Format: Both "#4472C4" and "4472C4" formats are accepted for colours (the # prefix is optional and will be stripped automatically).

Font Example:

{
  "function": "format_range",
  "filepath": "/path/to/workbook.xlsx",
  "sheet_name": "Sheet1",
  "options": {
    "range": "A1:D1",
    "font": {
      "bold": true,
      "size": 14,
      "colour": "#FF0000",
      "family": "Arial"
    },
    "fill": {
      "colour": "#FFFF00",
      "pattern": "solid"
    }
  }
}

Conditional Formatting Example:

{
  "function": "format_range",
  "filepath": "/path/to/workbook.xlsx",
  "sheet_name": "Sheet1",
  "options": {
    "range": "B2:B10",
    "conditional_format": {
      "type": "colour_scale",
      "rule": {
        "min_colour": "#FF0000",
        "max_colour": "#00FF00"
      }
    }
  }
}

Cell Operations

merge_cells

Merge a cell range.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Worksheet name
  • options.start_cell (required): Starting cell
  • options.end_cell (required): Ending cell

unmerge_cells

Unmerge a cell range.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Worksheet name
  • options.start_cell (required): Starting cell
  • options.end_cell (required): Ending cell

get_merged_cells

List all merged cell ranges in a worksheet.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Worksheet name

Range Operations

copy_range

Copy cells to another location.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Source worksheet name
  • options.source_range (required): Source range (e.g., "A1:C10")
  • options.target_cell (required): Target starting cell
  • options.target_sheet (optional): Target worksheet name (defaults to source sheet)

delete_range

Delete a range and shift cells.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Worksheet name
  • options.start_cell (required): Starting cell
  • options.end_cell (required): Ending cell
  • options.shift_direction (optional): "up" or "left" (default: "up")

validate_range

Validate that a range exists.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Worksheet name
  • options.start_cell (required): Starting cell
  • options.end_cell (optional): Ending cell

Row and Column Operations

insert_rows

Insert rows into a worksheet.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Worksheet name
  • options.start_row (required): Starting row number (1-based)
  • options.count (optional): Number of rows to insert (default: 1)

insert_columns

Insert columns into a worksheet.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Worksheet name
  • options.start_col (required): Starting column number (1-based)
  • options.count (optional): Number of columns to insert (default: 1)

delete_rows

Delete rows from a worksheet.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Worksheet name
  • options.start_row (required): Starting row number (1-based)
  • options.count (optional): Number of rows to delete (default: 1)

delete_columns

Delete columns from a worksheet.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Worksheet name
  • options.start_col (required): Starting column number (1-based)
  • options.count (optional): Number of columns to delete (default: 1)

Charts

create_chart

Create a chart in the worksheet.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Worksheet name
  • options.type (required): Chart type: "line", "bar", "column", "pie", "scatter", "area"
  • options.position (required): Cell position for chart (e.g., "E2")
  • options.title (optional): Chart title
  • options.x_axis_title (optional): X-axis title
  • options.y_axis_title (optional): Y-axis title
  • options.data_range (optional): Simple data range
  • options.series (optional): Detailed data series configuration
  • options.legend (optional): Legend configuration
  • options.size (optional): Chart dimensions (width, height)

Simple Example:

{
  "function": "create_chart",
  "filepath": "/path/to/workbook.xlsx",
  "sheet_name": "Sheet1",
  "options": {
    "type": "column",
    "position": "E2",
    "title": "Sales by Quarter",
    "data_range": "A1:C10"
  }
}

Advanced Example:

{
  "function": "create_chart",
  "filepath": "/path/to/workbook.xlsx",
  "sheet_name": "Sheet1",
  "options": {
    "type": "line",
    "position": "E2",
    "title": "Sales Trends",
    "x_axis_title": "Quarter",
    "y_axis_title": "Revenue (£)",
    "series": [
      {
        "name": "Product A",
        "categories": "A2:A10",
        "values": "B2:B10"
      },
      {
        "name": "Product B",
        "categories": "A2:A10",
        "values": "C2:C10"
      }
    ],
    "legend": {
      "show": true,
      "position": "bottom"
    },
    "size": {
      "width": 640,
      "height": 480
    }
  }
}

Pivot Tables

create_pivot_table

Create a native Excel pivot table.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Source worksheet name
  • options.source_range (required): Source data range (e.g., "A1:D100")
  • options.row_fields (required): Array of row field names
  • options.data_fields (required): Array of data field configurations
  • options.column_fields (optional): Array of column field names
  • options.filter_fields (optional): Array of filter field names
  • options.destination (optional): Destination sheet and cell (default: new sheet "Pivot1" at A1)
  • options.options (optional): Pivot table options (show_grand_totals, style)

Example:

{
  "function": "create_pivot_table",
  "filepath": "/path/to/workbook.xlsx",
  "sheet_name": "Sheet1",
  "options": {
    "source_range": "A1:D100",
    "row_fields": ["Category", "Product"],
    "data_fields": [
      {
        "field": "Sales",
        "function": "sum",
        "name": "Total Sales"
      },
      {
        "field": "Units",
        "function": "count",
        "name": "Units Sold"
      }
    ],
    "column_fields": ["Quarter"],
    "filter_fields": ["Region"],
    "destination": {
      "sheet": "Pivot Analysis",
      "cell": "A1"
    },
    "options": {
      "show_grand_totals": true,
      "style": "PivotStyleMedium9"
    }
  }
}

Aggregation Functions: sum, count, average, min, max, product, stddev, var

Excel Tables

create_table

Create a native Excel table object.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Worksheet name
  • options.range (required): Table range (e.g., "A1:D100")
  • options.name (optional): Table name (auto-generated if not provided)
  • options.style (optional): Table style name (default: "TableStyleMedium9")
  • options.show_header (optional): Show header row (default: true)
  • options.show_totals (optional): Show totals row (default: false)

Example:

{
  "function": "create_table",
  "filepath": "/path/to/workbook.xlsx",
  "sheet_name": "Sheet1",
  "options": {
    "range": "A1:D100",
    "name": "SalesTable",
    "style": "TableStyleMedium9",
    "show_header": true,
    "show_totals": false
  }
}

Formulas

apply_formula

Write a formula to a cell. Note that write_data also supports formulas inline - use this function when you need to add formulas to existing data or update individual cells.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Worksheet name
  • options.cell (required): Cell reference (e.g., "C1")
  • options.formula (required): Excel formula (with or without leading "=")

Example:

{
  "function": "apply_formula",
  "filepath": "/path/to/workbook.xlsx",
  "sheet_name": "Sheet1",
  "options": {
    "cell": "D2",
    "formula": "=SUM(B2:C2)"
  }
}

Note: Formulas are automatically calculated and cached for compatibility with Apple Numbers and other spreadsheet applications that don't have full formula calculation engines.

Security: Dangerous functions (INDIRECT, HYPERLINK, WEBSERVICE, DGET, RTD) are blocked for security reasons.

validate_formula_syntax

Validate formula syntax without applying it.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Worksheet name
  • options.cell (required): Cell reference
  • options.formula (required): Excel formula to validate

Data Validation

get_data_validation_info

Extract all data validation rules from a worksheet.

Parameters:

  • filepath (required): Path to Excel file
  • sheet_name (required): Worksheet name

Returns validation rules including type, operators, allowed values, prompts, and error messages.

Common Patterns

Create and Populate a Workbook

  1. create_workbook - Create the workbook
  2. write_data - Add data (can include formulas directly)
  3. format_range - Apply formatting
  4. create_chart - Add visualisations

Build a Report

  1. write_data - Write raw data
  2. create_table - Convert to Excel table
  3. create_pivot_table - Create analysis pivot table
  4. create_chart - Add charts for visualisation

Data Analysis Workflow

  1. read_data - Load data from source
  2. write_data - Write to analysis sheet (can include formulas directly in data)
  3. apply_formula - Add additional calculations (optional if formulas included in step 2)
  4. format_range - Apply conditional formatting
  5. create_pivot_table - Summarise data

Error Handling

Common Errors

Tool Not Enabled:

excel tool is not enabled. Set ENABLE_ADDITIONAL_TOOLS=excel to enable

Solution: Add excel to ENABLE_ADDITIONAL_TOOLS environment variable.

File Not Found:

workbook error during open on /path/to/file.xlsx: failed to open workbook

Solution: Verify file path is correct and file exists.

Worksheet Not Found:

worksheet error during operation on sheet 'SheetName': worksheet not found

Solution: Check worksheet name spelling and case sensitivity.

Invalid Cell Reference:

validation error for field 'cell' with value 'XYZ': invalid cell reference

Solution: Use valid Excel cell references (e.g., "A1", "B10").

Chart Type Error:

invalid chart type 'xyz', must be one of: line, bar, column, pie, scatter, area

Solution: Use a supported chart type.

Excel Limits

  • Maximum rows: 1,048,576
  • Maximum columns: 16,384 (column XFD)
  • Maximum cell value length: 32,767 characters
  • Maximum worksheet name length: 31 characters
  • Worksheet name restrictions: Cannot contain :\/?*[]

Performance Considerations

Large Files

  • Reading 10,000 rows: ~2 seconds
  • Writing 10,000 rows: ~3 seconds
  • Formatting 1,000 cells: ~1 second
  • Creating chart with 100 data points: ~1 second

Best Practices

  • Process data in batches for large datasets
  • Minimise file open/close operations by grouping operations
  • Use absolute file paths in STDIO mode
  • Apply formatting after data write operations
  • Limit conditional formatting rules for better performance

Security

File Access

  • Integrated with MCP DevTools security framework
  • Respects FILESYSTEM_TOOL_ALLOWED_DIRS configuration
  • Directory traversal prevention in HTTP mode
  • Files created with 0600 permissions

Formula Safety

  • Dangerous functions blocked: INDIRECT, HYPERLINK, WEBSERVICE, DGET, RTD
  • Formula validation before execution
  • Clear error messages for blocked functions

Compatibility

Generated Excel files are compatible with:

  • Microsoft Excel 2016+
  • LibreOffice Calc
  • Google Sheets (with some limitations on advanced features)

Excel features fully supported:

  • Workbook and worksheet operations
  • Data types: string, number, boolean, date, formula
  • Cell formatting and conditional formatting
  • Charts (line, bar, column, pie, scatter, area)
  • Native pivot tables
  • Excel tables with styling
  • Data validation rules
  • Formulas (with security restrictions)