Three critical fixes: 1. COM Cleanup Hardening (ExcelBatch.cs) - Wrap workbook.Close() and excel.Quit() in try/catch blocks - Catch COMException and MissingMemberException - Log warnings instead of crashing server - Fixes: RPC_E_DISCONNECTED (0x80010108) unhandled exceptions 2. Add Error Messages to Worksheet Tool (ExcelWorksheetTool.cs) - List action now includes errorMessage in JSON response - Create action now includes errorMessage in JSON response - LLMs can now diagnose failures properly 3. Fix CreateEmpty Save (FileCommands.cs) - Call ctx.Book.Save() before batch disposal - Ensures Sheet1 rename and comment are persisted - Fixes: corrupted workbook state after CreateEmpty Tests Added (FileCommandsTests.CreateEmptyThenList.cs): - CreateEmpty_ThenOpenAndList_ReturnsSheet1 - CreateEmpty_ThenOpenAndListMultipleTimes_ConsistentResults - CreateEmpty_ThenOpenAndCreateMoreSheets_AllSheetsVisible All 15 file-related tests pass. Fixes #192 Co-authored-by: Stefan Broenner <stefan.broenner@microsoft.comm>
ExcelMcp - MCP Server for Microsoft Excel
Automate Excel with AI - A Model Context Protocol (MCP) server for comprehensive Excel automation through conversational AI.
ExcelMcp is a comprehensive Excel automation toolkit with two interfaces:
- MCP Server: Enables AI assistants (GitHub Copilot, Claude, ChatGPT) to automate Excel through natural language commands
- CLI Tool: Provides direct command-line control for scripting, RPA, and CI/CD workflows
Both share the same core functionality: automate Power Query, DAX measures, VBA macros, PivotTables, formatting, and data transformations. Choose MCP for AI-powered conversations or CLI for programmatic control - no Excel programming knowledge required. Built on Excel's native COM API for zero risk of file corruption.
💡 Interactive Development: Unlike file-based tools, ExcelMcp lets you see results instantly in Excel - create a query, run it, inspect the output, refine and repeat. Excel becomes your interactive workspace for rapid development and testing.
🤔 What is This?
Use natural language OR command-line to automate complex Excel tasks - your choice.
Stop manually clicking through Excel menus for repetitive tasks. Instead, describe what you want in plain English:
Data Transformation & Analysis:
- "Optimize all my Power Queries in this workbook for better performance"
- "Create a PivotTable from SalesData table showing top 10 products by region with sum and average"
- "Build a DAX measure calculating year-over-year growth with proper time intelligence"
Formatting & Styling (No Programming Required):
- "Format the revenue columns as currency, make headers bold with blue background, and add borders to the table"
- "Apply conditional formatting to highlight values above $10,000 in red and below $5,000 in yellow"
- "Convert this data range to an Excel Table with style TableStyleMedium2, add auto-filters, and create a totals row"
Workflow Automation:
- "Find all cells containing 'Q1 2024' and replace with 'Q1 2025', then sort the table by Date descending"
- "Add data validation dropdowns to the Status column with options: Active, Pending, Completed"
- "Merge the header cells, center-align them, and auto-fit all column widths to content"
The AI assistant analyzes your request, generates the proper Excel automation commands, and executes them directly in your Excel application - no formulas or programming knowledge required.
Real-World Example - Power Query Optimization:
You: "This Power Query is taking 5 minutes to refresh. Can you optimize it?"
AI Assistant (using ExcelMcp):
1. Exports the M code to analyze performance bottlenecks
2. Identifies queries that can use query folding
3. Refactors the M code to push operations to the data source
4. Updates the query in your workbook
5. Tests the refresh (now completes in 30 seconds)
Result: A professionally optimized Power Query with documented improvements
🛡️ 100% Safe - Uses Excel's Native COM API
Unlike third-party libraries that manipulate .xlsx files directly (risking file corruption), ExcelMcp uses Excel's official COM API. This ensures:
- ✅ Zero risk of document corruption - Excel handles all file operations safely
- ✅ Interactive development - See changes in real-time, create → test → refine → iterate instantly
- ✅ Comprehensive automation - Currently supports 163 operations across 12 specialized tools covering Power Query, Data Model/DAX, VBA, PivotTables, Excel Tables, ranges, conditional formatting, and more
💻 For Developers: Think of Excel as an AI-powered REPL - write code (Power Query M, DAX, VBA), execute instantly, inspect results visually in the live workbook. No more blind editing of .xlsx files.
🔧 Advanced Features:
- Batch Operations - Group multiple operations in a single Excel session for 75-90% faster execution
- Progress Logging - Real-time operation status updates via stderr (MCP protocol compatible)
- Error Recovery - Intelligent retry suggestions and operation-specific troubleshooting guidance
👥 Who Should Use This?
Perfect for:
- ✅ Data analysts automating repetitive Excel workflows
- ✅ Developers building Excel-based data solutions
- ✅ Business users managing complex Excel workbooks
- ✅ Teams maintaining Power Query/VBA/DAX code in Git
Not suitable for:
- ❌ Server-side data processing (use libraries like ClosedXML, EPPlus instead)
- ❌ Linux/macOS users (Windows + Excel installation required)
- ❌ High-volume batch operations (consider Excel-free alternatives)
🎯 What You Can Do
Development & Automation:
- 🔄 Power Query - 11 operations: atomic workflows (create, update-and-refresh, refresh-all), manage transformations, load configurations (worksheet, data model, connection only), M code evaluation
- 📊 Power Pivot (Data Model) - 14 operations: build DAX measures, manage relationships, discover model structure (tables, columns)
- 🎨 Excel Tables - 26 operations: automate formatting, filtering, sorting, structured references, number formats, column management
- 📈 PivotTables - 20 operations: create and configure PivotTables for interactive analysis
- 📝 VBA Macros - 7 operations: export/import/run VBA code, integrate with version control
- 📋 Ranges & Data - 45 operations: values, formulas, copy/paste, find/replace, formatting, validation, merge, conditional formatting, cell protection
- 📄 Worksheets - 13 operations: lifecycle management, tab colors, visibility controls
- 🔌 Connections - 9 operations: manage OLEDB, ODBC, Text, Web data sources
- 🏷️ Named Ranges - 7 operations: named range management and bulk operations
📚 See Complete Feature List (100+ Operations)
Power Query & M Code (11 operations)
✨ NEW: Atomic Operations - Single-call workflows replace multi-step patterns:
- Create - Import + load in one operation (replaces import → load workflow)
- Update & Refresh - Update M code + refresh data atomically
- Refresh All - Batch refresh all queries in workbook
- Update M Code - Stage code changes without refreshing data
- Unload - Convert loaded query to connection-only
Core Operations:
- List, view, delete Power Query transformations
- Manage query load destinations (worksheet/data model/connection-only/both)
- Get load configuration for existing queries
- List Excel workbook sources for Power Query integration
Data Model & DAX (Power Pivot) (14 operations)
- Create/update/delete DAX measures with format types (Currency, Percentage, Decimal, General)
- Manage table relationships (create, toggle active/inactive, delete)
- Discover model structure (tables, columns, measures, relationships)
- Get comprehensive model information
- Refresh data model
- Note: DAX calculated columns are not supported (use Excel UI for calculated columns)
Excel Tables (ListObjects) (26 operations)
- Lifecycle: create, resize, rename, delete, get info
- Styling: apply table styles, toggle totals row, set column totals
- Column management: add, remove, rename columns
- Data operations: append rows, apply filters (criteria/values), clear filters, get filter state
- Sorting: single-column sort, multi-column sort (up to 3 levels)
- Number formatting: get/set column number formats
- Advanced features: structured references, Data Model integration
PivotTables (20 operations)
- Creation: create from ranges or Excel Tables
- Field management: add/remove fields to Row, Column, Value, Filter areas
- Aggregation functions: Sum, Average, Count, Min, Max, etc. with validation
- Advanced features: field filters, sorting, custom field names, number formatting
- Data extraction: get PivotTable data as 2D arrays for further analysis
- Lifecycle: list, get info, delete, refresh
VBA Macros (7 operations)
- List all VBA modules and procedures
- View module code without exporting
- Export/import VBA modules to/from files
- Update existing modules
- Execute macros with parameters
- Delete modules
- Version control VBA code through file exports
Ranges & Worksheets
- Data Operations (10 actions): get/set values/formulas, clear (all/contents/formats), copy/paste (all/values/formulas), insert/delete rows/columns/cells, find/replace, sort
- Number Formatting (3 actions): get formats as 2D arrays, apply uniform format, set individual cell formats
- Visual Formatting (1 action): font (name, size, bold, italic, underline, color), fill color, borders (style, weight, color), alignment (horizontal, vertical, wrap text, orientation)
- Data Validation (3 actions): add validation rules (dropdowns, number/date/text rules), get validation info, remove validation
- Hyperlinks (4 actions): add, remove, list all, get specific hyperlink
- Smart Range Operations (3 actions): UsedRange, CurrentRegion, get range info (address, dimensions, format)
- Merge Operations (3 actions): merge cells, unmerge cells, get merge info
- Auto-Sizing (2 actions): auto-fit columns, auto-fit rows
- Conditional Formatting (2 actions): add conditional formatting, clear conditional formatting
- Cell Protection (2 actions): set cell lock status, get cell lock status
- Formatting & Styling (3 actions): get style, set style, format range
- 45 range operations total covering all common Excel range manipulation needs
- Worksheet management (13 actions): lifecycle (create, rename, copy, delete), tab colors (set, get, clear), visibility controls (show, hide, very-hide, get/set status)
Data Connections (11 operations)
- Manage OLEDB, ODBC, Text, Web connections
- Import/export connections via .odc files
- Update connection strings and properties
- Refresh connections and test connectivity
- Load connection-only connections to worksheet tables
- Get/set connection properties (refresh settings, background query, etc.)
Named Ranges (7 operations)
- List all named ranges with references
- Get/set single values
- Create/delete named ranges
- Update cell references
- Bulk create multiple parameters
🚀 Quick Start (2 Minutes)
Requirements: Windows OS + Microsoft Excel 2016+
⚠️ Important: Close all Excel files before using ExcelMcp. The server requires exclusive access to workbooks during automation (Excel COM limitation).
⭐ Recommended: VS Code Extension (One-Click Setup)
Fastest way to get started - everything configured automatically:
-
Install Extension
- Open VS Code → Extensions (
Ctrl+Shift+X) - Search for "ExcelMcp"
- Click Install
- Open VS Code → Extensions (
-
Automatic Setup (no manual steps!)
- ✅ Installs .NET 8 runtime
- ✅ Includes bundled MCP server
- ✅ Registers with AI assistants
- ✅ Shows quick start guide
-
Start Using It
The extension opens automatically after installation with a quick start guide!
Manual Installation (Advanced Users)
For non-VS Code environments or manual setup:
# Install .NET 8 SDK
winget install Microsoft.DotNet.SDK.8
# Install ExcelMcp MCP server as a global tool
dotnet tool install --global Sbroenne.ExcelMcp.McpServer
# To update to the latest version later:
dotnet tool update --global Sbroenne.ExcelMcp.McpServer
Configure Your AI Assistant
ExcelMcp works with multiple AI coding assistants. Choose your setup:
🎯 Quick Setup: Ready-to-use config files → examples/mcp-configs/
For GitHub Copilot in VS Code - Create .vscode/mcp.json in your workspace:
{
"servers": {
"excel": {
"command": "dotnet",
"args": ["tool", "run", "mcp-excel"]
}
}
}
For GitHub Copilot in Visual Studio - Create .mcp.json in your solution directory or %USERPROFILE%\.mcp.json:
{
"servers": {
"excel": {
"command": "dotnet",
"args": ["tool", "run", "mcp-excel"]
}
}
}
For Claude Desktop - Edit %APPDATA%\Claude\claude_desktop_config.json:
{
"mcpServers": {
"excel": {
"command": "dotnet",
"args": ["tool", "run", "mcp-excel"]
}
}
}
For Cursor - Add to settings or %APPDATA%\Cursor\User\globalStorage\mcp\mcp.json:
{
"mcpServers": {
"excel": {
"command": "dotnet",
"args": ["tool", "run", "mcp-excel"]
}
}
}
For Cline (VS Code Extension) - Use the MCP settings panel in Cline or edit settings:
{
"mcpServers": {
"excel": {
"command": "dotnet",
"args": ["tool", "run", "mcp-excel"]
}
}
}
For Windsurf - Add to MCP servers configuration:
{
"mcpServers": {
"excel": {
"command": "dotnet",
"args": ["tool", "run", "mcp-excel"]
}
}
}
📖 Detailed setup for each client: Installation Guide
Test It Out
Try a practical example - ask your AI assistant:
Create an empty Excel file called "test.xlsx" and add a Power Query that loads data from a CSV file
The AI will guide you through the process and execute the commands directly!
🔧 How It Works - COM Interop Architecture
ExcelMcp uses Windows COM automation to control the actual Excel application (not just .xlsx files).
This means you get:
- ✅ Full Excel Feature Access - Power Query engine, VBA runtime, Data Model, calculation engine, pivot tables
- ✅ True Compatibility - Works exactly like Excel UI, no feature limitations
- ✅ Live Data Operations - Refresh Power Query, connections, Data Model in real workbooks
- ✅ Interactive Development - Immediate Excel feedback as AI makes changes
- ✅ All File Formats - .xlsx, .xlsm, .xlsb, even legacy formats
Technical Requirements:
- ⚠️ Windows Only - COM interop is Windows-specific
- ⚠️ Excel Required - Microsoft Excel 2016 or later must be installed
- ⚠️ Desktop Environment - Controls actual Excel process (not for server-side processing)
🔟 MCP Tools Overview
12 specialized tools for comprehensive Excel automation:
- excel_powerquery (11 actions) - Power Query M code: create, view, update, delete, refresh, load configuration, list Excel sources
- excel_datamodel (14 actions) - Power Pivot (Data Model): CRUD DAX measures/relationships, discover structure (tables, columns), refresh
- excel_table (26 actions) - Excel Tables: lifecycle, columns, filters, sorts, structured references, totals, number formatting, Data Model integration
- excel_pivottable (20 actions) - PivotTables: create from ranges/tables, field management (row/column/value/filter), aggregations, filters, sorting, extract data
- excel_range (43 actions) - Ranges: get/set values/formulas, number formatting, visual formatting (font, fill, border, alignment), data validation, clear, copy, insert/delete, find/replace, sort, hyperlinks, merge, cell protection
- excel_conditionalformat (2 actions) - Conditional Formatting: add rules (cell value, expression-based), clear rules
- excel_vba (6 actions) - VBA: list, view, import, update, run, delete modules
- excel_connection (9 actions) - Connections: OLEDB/ODBC/Text/Web management, properties, refresh, test
- excel_worksheet (13 actions) - Worksheets: lifecycle (list, create, rename, copy, delete), tab colors (set-tab-color, get-tab-color, clear-tab-color), visibility (set-visibility, get-visibility, show, hide, very-hide)
- excel_namedrange (7 actions) - Named ranges: list, get, set, create, create-bulk, delete, update
- excel_querytable (8 actions) - QueryTables: create from connections/queries, refresh, update properties, delete
- excel_file (6 actions) - File operations: create empty, open, save, close, close-workbook, test
Total: 12 tools with 163 actions
📚 Complete MCP Server Guide → - Detailed tool documentation and examples
📋 Additional Information
Testing Philosophy
Why No Unit Tests? ExcelMcp uses integration tests exclusively because Excel COM cannot be meaningfully mocked. Our integration tests ARE our unit tests. See ADR-001: No Unit Tests for full architectural rationale.
CLI for Direct Automation
ExcelMcp also provides a command-line interface for Excel automation (no AI required). Run excelcli --help for a categorized list of commands, or excelcli sheet --help (replace sheet) to view action-specific options. Always follow the session pattern: excelcli session open <file> → run commands with --session <id> → excelcli session save/close <id>. See CLI Guide for complete documentation.
Project Information
License: MIT License - see LICENSE file
Contributing: See CONTRIBUTING.md for guidelines
Built With: This entire project was developed using GitHub Copilot AI assistance
Acknowledgments:
- Microsoft Excel Team - For comprehensive COM automation APIs
- Model Context Protocol community - For the AI integration standard
- Open Source Community - For inspiration and best practices
SEO & Discovery
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