Stefan Broenner
0bb29be3be
* Fix #279: Power Query lifecycle cleanup for Data Model connections BREAKING CHANGES: - Unload now removes Data Model connections (not just worksheet tables) - Delete now removes Data Model connections (prevents orphan connections) IMPROVEMENTS: - List correctly reports IsConnectionOnly for Data Model-only queries - Update uses connection.Refresh() fallback for Data Model-only queries (no worksheet table to refresh) NEW TESTS: - PowerQueryCommandsTests.LifecycleCleanup.cs: 8 tests for Issue #279 - PowerQueryCommandsTests.UpdateErrors.cs: 3 tests for error handling - DataModelComApiBehaviorTests.cs: 11 diagnostic scenarios - PowerQueryComApiBehaviorTests.cs: 15 diagnostic scenarios DOCUMENTATION: - docs/COM-API-BEHAVIOR-FINDINGS.md: Empirical COM API behavior findings - excel_powerquery.md: Updated prompt docs for Data Model cleanup DELETED: - PowerQueryCommandsTests.ErrorQueries.cs: Referenced non-existent local file All 53 PowerQuery and DataModel tests pass. * fix: Use locale-aware format translation instead of global Excel settings - Renamed DateFormatTranslator to NumberFormatTranslator - Extended translator to handle decimal/thousands separators (. and ,) - Removed global UseSystemSeparators/DecimalSeparator/ThousandsSeparator settings from ExcelSession and ExcelBatch (these modified Excel app defaults) - Added IsEnglishNumberLocale property to detect US-style number separators - Format codes are now translated at point of use, not by changing app defaults - Updated all references from DateFormatter to FormatTranslator - Removed unused WithUSFormatSeparators helper from RangeCommands This approach translates US format codes (like $#,##0.00) to locale-specific codes (like $#.##0,00 on German Excel) without modifying Excel's global settings. Previous approach of changing Application.DecimalSeparator affected all workbooks in the Excel instance, which is not desirable. * feat: DAX formula locale handling for European locales (#281) - Add DaxFormulaTranslator to convert US comma separators to semicolons on European locales - Integrate translator in CreateMeasure and UpdateMeasure operations - Power Pivot uses system culture (CultureInfo.CurrentCulture), not Excel International settings - Preserve commas inside string literals and column references - Add 5 integration tests for DAX locale translation
ExcelMcp - MCP Server for Microsoft Excel
Automate Excel with AI - A Model Context Protocol (MCP) server for comprehensive Excel automation through conversational AI.
MCP Server for Excel enables AI assistants (GitHub Copilot, Claude, ChatGPT) to automate Excel through natural language commands. Automate Power Query, DAX measures, VBA macros, PivotTables, Charts, formatting, and data transformations - no Excel programming knowledge required.
🛡️ 100% Safe - Uses Excel's Native COM API - Zero risk of file corruption. Unlike third-party libraries that manipulate .xlsx files directly, this project uses Excel's official API ensuring complete safety and compatibility.
💡 Interactive Development - See results instantly in Excel. Create a query, run it, inspect the output, refine and repeat. Excel becomes your AI-powered workspace for rapid development and testing.
Optional CLI Tool: For advanced users who prefer command-line scripting, ExcelMcp includes a CLI interface for RPA workflows, CI/CD pipelines, and batch automation. Both interfaces share the same 173 operations.
🚀 Quick Start (1 Minute)
Requirements: Windows OS + Microsoft Excel 2016+
⭐ Recommended: VS Code Extension (One-Click Setup)
Fastest way to get started - everything configured automatically: Install from Marketplace
The extension opens automatically after installation with a quick start guide!
For Visual Studio, Claude Desktop, Cursor, Windsurf, or other MCP clients:
📖 Complete Installation Guide → - Step-by-step setup for all AI assistants with ready-to-use config files
⚠️ Important: Close all Excel files before using ExcelMcp. The server requires exclusive access to workbooks during automation (Excel COM limitation).
🎯 What You Can Do
12 specialized tools with 173 operations:
- 🔄 Power Query (9 ops) - Atomic workflows, M code management, load destinations
- 📊 Data Model/DAX (14 ops) - Measures, relationships, model structure
- 🎨 Excel Tables (24 ops) - Lifecycle, filtering, sorting, structured references
- 📈 PivotTables (25 ops) - Creation, fields, aggregations, data extraction
- 📉 Charts (14 ops) - Create, configure, manage series and formatting
- 📝 VBA (6 ops) - Modules, execution, version control
- 📋 Ranges (42 ops) - Values, formulas, formatting, validation, protection
- 📄 Worksheets (16 ops) - Lifecycle, colors, visibility, cross-workbook moves
- 🔌 Connections (9 ops) - OLEDB/ODBC management and refresh
- 🏷️ Named Ranges (6 ops) - Parameters and configuration
- 📁 Files (5 ops) - Session management and workbook creation
- 🎨 Conditional Formatting (2 ops) - Rules and clearing
📚 Complete Feature Reference → - Detailed documentation of all 173 operations
💬 Example Prompts
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"
- "Create a data model from the following tables ... "
- "Build a DAX measure calculating year-over-year growth with proper time intelligence"
- "Filter this table by Column Product = Sushi"
- *"Create a treemap chart from this table".
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"
👥 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)
📋 Additional Information
CLI for Direct Automation
xcelMcp includes a CLI interface for Excel automation without AI assistance. This is useful for RPA workflows, CI/CD pipelines, or batch processing scripts. 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.
🔧 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
💡 Tip: Watch Excel While AI Works By default, Excel runs hidden for faster automation. To see changes in real-time, just ask:
- "Show me Excel while you work"
- "Let me watch what you're doing"
- "Open Excel so I can see the changes"
The AI will display the Excel window so you can watch every operation happen live - great for learning or verifying changes!
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)
📚 Complete MCP Server Guide → - Detailed tool documentation and examples
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 - mainly with Claude but lately with Auto-mode.
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
Excel Automation • Automate Excel with AI • MCP Server • Model Context Protocol • GitHub Copilot Excel • AI Excel Assistant • Power Query Automation • Power Query M Code • Power Pivot Automation • DAX Measures • DAX Automation • Data Model Automation • PivotTable Automation • VBA Automation • Excel Tables Automation • Excel AI Integration • COM Interop • Windows Excel Automation • Excel Development Tools • Excel Productivity • Excel Scripting • Conversational Excel • Natural Language Excel