OpenPyXL Excel

Windows will try to talk you out of running a random executable downloaded from the internet. You will have to click "Keep" or "Keep anyway" in various places to convince it to not delete the file. The details of this depend on which browser you use and what your Windows Defender settings are.

Alternatively, if you don't trust my executables, you can also install the source version of the code directly from this repo. See the "From Source" section below.

- macOS:~/Library/Application Support/Claude/claude_desktop_config.json
- Windows:%APPDATA%\Claude\claude_desktop_config.json

Instructions for configuring MCP servers in other tools that support them:

This section only applies if you wish to modify the source code or if you do not trust the provided executables and prefer to run from source code.

git clone git@github.com:jonemo/openpyxl-mcp-server.git cd openpyxl-mcp-server python -m venv venv source venv/bin/activate pip install -r requirements.txt

Assuming you've cloned your repo to/Users/jonas/repos/openpyxl_mcp_server, the configuration file contents should now change to:

From a quick glance at description and file contents it wasn't obvious to me what ports this dataset is about. Let's ask Claude:

I have an Excel file in ~/Downloads/KimbroughEvelyn_A-5qg0_Dataset_20160624.xlsx that contains data associated with some study about air pollution near one or more ports in the United States. Can you infer from the file contents which ports are covered by this study?

After 11 calls to the MCP server, the response is:

Looking at the latitude and longitude coordinates from the Fig 2 sheet and combining this with the location information, I can infer that this study is focused on the Port of Charleston, South Carolina.

The coordinates in the dataset (approximately latitude 32.83 and longitude -79.87) correspond to the Charleston area, and the references to downtown, rail yard, and airport monitoring stations are consistent with air quality monitoring around a port city.

This dataset appears to contain air pollution measurements (PM2.5 and PM10) collected near the Port of Charleston, with comparisons between port locations and background/reference sites.

I'm the treasurer of a small 10-unit home owners association. Our book keeping happens in an Excel file in Google Sheets. The file has 9 sheets with nine sheets for things like the transactions list, members' dues accounts, quarterly reports.

The file contains non-public information, therefore this example only shows the prompt, a few key "insights", and the final answer:

~/Downloads/CASH FLOW 2024.xlsx are the finances of my home owner association. How much did we get billed for sprinkler system maintenance in 2024? How many transactions contributed to this total? When did each transaction happen?

I see a "Transactions" sheet that likely contains the detailed expense records. Let me search for "sprinkler" in this sheet to find relevant transactions:

Let me examine the YEAR 2024 summary sheet to see if sprinkler maintenance is listed as a category:

Great! I found "Sprinkler Maintenance" listed as a category in row 24 of the YEAR 2024 sheet. Now, let me check the actual transactions related to sprinkler maintenance:

Let me check more entries by searching specifically for "Sprinkler Maintenance" in the entire Transactions sheet:

Based on my analysis of your HOA's financial records in the "CASH FLOW 2024.xlsx" file, here's what I found about the sprinkler system maintenance expenses in 2024:

Total amount billed for sprinkler system maintenance in 2024: $565.00 Number of transactions: 1 transaction Transaction date: September 9, 2024

The expense appears as a single transaction in the Transactions sheet. The spreadsheet also contains a budgeted amount for sprinkler maintenance of $750.00 for the year > in the "YEAR 2024 Actuals vs Planned" sheet, with a note stating "Not received any invoices yet" (which may be outdated since there is now one invoice recorded). Would you like me to analyze any other aspects of your HOA's sprinkler maintenance expenses or other financial information from the spreadsheet?

True story. Our sprinkler guy only billed us for the one visit in the spring and forgot to send the bill for the work later in the year. Don't worry, he got paid but it's booked in 2025.

I need to file DPR973 because I work for a "cooperating association" for California State Parks. The form I have to fill out is this Excel sheet: /Users/jonas/Downloads/Annual Report DPR973.xlsx. We supported the State Parks by publishing books and generated revenue by selling firewood. Where in the workbook do I have to fill out cells?

After 11 calls to the tool the response seems correct, although I don't understand why Claude did not look at the remaining sheets at all:

Based on my examination of the DPR973 form, I'll now provide guidance on where you need to fill out cells for your cooperating association that publishes books and sells firewood:

- You'll need to fill out the Association Information (Part I) with your organization's details (name, address, contact information)
- Update the year in cell C4 to the current reporting year

Page 2 (A)- This is where you'll record your sales information:

-

For your book sales (which would be considered interpretive/educational):

- Line 1 (Cell F22): Gross Sales - Materials (for your published books)
- Line 2 (Cell F23): Any returns or refunds
- Line 3 (Cell F24): Cost of Goods Sold for the books

- Line 23 (Cell F51): Gross Sales - Firewood
- Line 24 (Cell F52): Any refunds/returned/damaged firewood
- Line 25 (Cell F53): Cost of Goods Sold for firewood

The form will automatically calculate totals in cells F25 (book profits), F54 (firewood profits), and F58 (total net profits)

-

Your sales figures will automatically populate from Page 2(A) into:

- Line 6 (Cell F11): Total gross sales
- Line 7 (Cell F12): Total cost of goods/services + returns/refunds
- Line 8 (Cell H13): Net profits for all materials and services

- Any donations/contributions (Line 1, Cell F6)
- Membership dues if applicable (Line 4, Cell H9)
- Interest/investment income if any (Line 5, Cell H10)
- Fundraising information if applicable (Lines 9-11)
- Other income if applicable (Line 12, Cell H17)

- Line 15 (Cell F21): Any direct grants to California State Parks
- Line 16 (Cell F22): Interpretive program support expenses
- Line 17 (Cell F23): Other CSP program support
- Line 19 (Cell H25): Management and general expenses

- Line 22 (Cell F30): Total assets
- Line 23 (Cell H31): Total liabilities
- Lines 24-26 (Cells F32-F34): Net assets by restriction type

Page 4(not fully examined but likely contains):

- Additional notes, explanations, and signatures

For your specific activities (book publishing and firewood sales), focus on accurately completing:
- The Interpretive and Educational Sales section on Page 2(A) for your book sales
- The Firewood Sales section on Page 2(A) for your firewood revenue
- The complete financial summary on Page 3

Would you like me to explain any specific section in more detail?

Using the Excel file in "/Users/jonas/Downloads/2025-3-7-iolp-buildings.xlsx": What is the largest federal building by square footage in the state of Utah?

I used this file and prompt repeatedly as test case and got mixed results:

To create standalone executables that don't require Python installation:
-

Make sure you have all dependencies installed:

pip install -r requirements.txt pip install -r requirements-dev.txt

The executable will be created in thedistdirectory. On Windows, it will be namedopenpyxl_mcp_server.exe. On macOS, it will be namedopenpyxl_mcp_server.

Note: When building on macOS, you might need to sign the executable for it to run properly. You can do this with:

codesign --force --deep --sign - dist/openpyxl_mcp_server

openpyxl-mcp-server is currently listed in these MCP server directories:

Read and analyze Excel (.xlsx) and CSV (.csv) files with scalable, chunked, and column-specific data access, ideal for large datasets.

An MCP server for manipulating and managing Excel files.

An MCP server for accurately reading, analyzing, and editing Excel (.xlsx) workbooks while preserving existing structure, styles, formulas, and data integrity. Supports cell operations, sheet and row/column management, formatting, data aggregation, formula recalculation, and safe concurrent file access.

A server for processing PDF files, allowing text and table extraction, metadata retrieval, and file listing within a specific directory.

Read, analyze, and manipulate data in Excel (XLSX, XLS) and CSV files with advanced filtering and analytics.

A high-performance MCP server for comprehensive JSON file operations, including reading, writing, and advanced querying, optimized for LLM interactions.

Read large Excel files with automatic chunking and pagination support.

Access and manage local music collections with advanced metadata, classification, and analytics.