Stefan Broenner
d72d8f8d1b
* chore: remove telemetry diagnostic output
* chore: update packages to .NET 10 and MCP SDK 0.4.1-preview.1
- Microsoft.Extensions.Hosting: 9.0.10 -> 10.0.0
- Microsoft.Extensions.Logging: 9.0.10 -> 10.0.0
- Microsoft.Extensions.Configuration: 9.0.10 -> 10.0.0
- Microsoft.Extensions.DependencyInjection: 9.0.10 -> 10.0.0
- System.Text.Json: 9.0.10 -> 10.0.0
- ModelContextProtocol: 0.4.0-preview.3 -> 0.4.1-preview.1
All packages forward-compatible with .NET 8.0 runtime.
No breaking changes - verified build passes with 0 warnings.
* refactor: migrate MCP tools from [Description] attributes to XML documentation
- Convert all 12 tool files to use XML docs (/// <summary>, /// <param>)
- XML docs processed by MCP SDK's XmlToDescriptionGenerator source generator
- Remove all CA1861 pragma warnings and [SuppressMessage] attributes (not needed)
- Remove dead code: ThrowUnknownAction() and invalid action error handlers
- Add GlobalUsings.cs for Chart and Range namespaces
- Update mcp-server-guide.instructions.md with NO EMOJIS rule
The XmlToDescriptionGenerator converts XML comments to [Description] attributes
at compile time, providing better IDE support and documentation integration.
* feat(mcp): add tool categories and remove outdated LLM guidance
- Add [McpMeta("category", "...")] to all 12 tools for better LLM discovery
- Remove unhelpful LLM guidance (suggestedNextActions, retryGuidance, workflowHint, operationContext)
- Update ExcelResourceProvider to use excel_file sessions
Follows principle: state facts, not guidance - LLMs figure out next steps
* fix: add prominent warning to prevent premature session close
- Update ServerInstructions in Program.cs to explicitly warn LLMs:
- WAIT for ALL pending tool calls before closing
- Closing while operations running causes failures
- Expand excel_file tool description with detailed session lifecycle
- Addresses race condition where close was called during parallel operations
* feat: add showExcel parameter to watch Excel during automation
- Add showExcel parameter to excel_file open action
- When true, Excel window becomes visible during operations
- Perfect for debugging, demos, and learning what AI is doing
Implementation:
- ExcelFileTool: Added showExcel parameter to ExcelFile() and OpenSessionAsync()
- SessionManager: Added showExcel parameter to CreateSession()
- ExcelSession: Added BeginBatch overload with showExcel parameter
- ExcelBatch: Sets Excel.Visible based on showExcel flag
Server instructions:
- Added prominent session close warnings (wait for all operations)
- LLM instructed to proactively offer showExcel for complex tasks
- Example prompt: 'Would you like me to show Excel so you can watch?'
Documentation updated:
- README.md: User-facing section with natural language examples
- FEATURES.md: Added to File Operations section
- INSTALLATION.md: Added tip after test installation step
- gh-pages/index.md: Added tip to Interactive Development feature
- McpServer README: Added to AI-Powered Workflows list
- VS Code extension copilot-instructions.md: LLM guidance
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 172 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 172 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 172 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
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