sbroenne__mcp-server-excel/src/ExcelMcp.ComInterop

ExcelMcp.ComInterop

Low-level COM interop utilities for Excel automation by Sbroenne.

Overview

This library provides Excel-specific COM object lifecycle management and OLE message filtering. It's the foundation layer for ExcelMcp projects, handling STA threading, session management, and batch operations specifically for Excel COM automation.

Note: Despite the generic name "ComInterop", this library is Excel-specific and not intended for Word/PowerPoint/other Office applications.

Features

• STA Threading Management - Ensures proper single-threaded apartment model for Excel COM objects
• COM Object Lifecycle - Automatic COM object cleanup and garbage collection
• OLE Message Filtering - Handles busy/rejected COM calls with retry logic using Polly
• Excel Session Management - Manages Excel.Application lifecycle safely
• Batch Operations - Efficient handling of multiple Excel operations in a single session

Usage Example

using Sbroenne.ExcelMcp.ComInterop;

// Use ExcelSession for safe Excel automation
await using var session = await ExcelSession.BeginAsync("path/to/workbook.xlsx");
await using var batch = await session.BeginBatchAsync();

await batch.ExecuteAsync<int>(async (ctx, ct) => 
{
    // Access Excel workbook through ctx.Book
    dynamic worksheets = ctx.Book.Worksheets;
    dynamic sheet = worksheets.Item[1];
    
    // Perform Excel operations
    sheet.Name = "UpdatedSheet";
    
    return 0;
});

await batch.Save();

Key Classes

• ExcelSession - Manages Excel.Application lifecycle and workbook operations
• ExcelBatch - Groups multiple operations for efficient execution
• ComUtilities - Helper methods for COM object cleanup and safe property access
• OleMessageFilter - Implements retry logic for busy Excel instances

Requirements

• Windows OS
• .NET 8.0 or later
• Microsoft Excel 2016+ installed

Platform Support

• ✅ Windows x64
• ✅ Windows ARM64
• ❌ Linux (Excel COM not available)
• ❌ macOS (Excel COM not available)