
Excel Vision Mcp
io.github.VOYAGER-IncPublished by GitHub account VOYAGER-Incv1.2.1Updated Oct 24, 2026
Excel MCP with image extraction and write support — AI agents see and edit xlsx files
Overview
A local MCP server that lets an AI assistant read and edit Excel workbooks, including embedded images returned as viewable image content.
- What you can do
- List sheets and get workbook overviews with dimensions and image counts, and search cells across sheets with pagination and optional hidden rows and columns. Read cell data with formatting markers for bold, strikethrough, highlights and font colors, or read all text and embedded images in one call. Extract embedded images as image content mapped to their cell positions. Create workbooks and sheets, update cells and write formulas, and write blocks of tabular rows. Insert local images into a workbook and apply formatting, borders, number formats and column widths.
- When to use it
- Useful when reviewing or producing .xlsx or .xlsm files where meaning lives in pasted diagrams, screenshots or cell formatting, such as requirements specs, reports or annotated spreadsheets. Also suited to assistants that need to create or edit workbooks rather than only read them.
- Requirements
- Runs locally as a Python package over stdio, launched with uvx or pip install, or via Docker with the file directory mounted. No accounts, API keys or network access are needed. Optionally set EXCEL_VISION_MCP_ALLOWED_DIRS to restrict which directories can be read or written. Only .xlsx and .xlsm are supported; .xls and .csv are not.
Installation
In SourceWeft
- Open Excel Vision Mcp in the dashboard and add it to a workspace.
- Enable the server for the chats that should use its tools.
Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.
Other MCP clients
Follow the launch instructions in the repository.
README
📊 Excel Vision MCP
Your AI reads the spreadsheet. It can't see the diagram in cell B12.
This fixes that. Other Excel MCP servers return cell values and silently drop every embedded image, so the flowchart your spec depends on never reaches the model. Excel Vision MCP returns them as native ImageContent your AI can actually look at — alongside the text, formatting, and formulas.
[Python 3.11+] [License: MIT] [MCP] [PyPI]
Installation · Tools · Configuration · How It Works · FAQ
🤔 The Problem
Ask your assistant to review a requirements spec. Half the meaning lives in screenshots, flowcharts, and annotated diagrams pasted into cells — and every Excel MCP server hands the model text only. The answer comes back confident and incomplete, because the model never knew the pictures existed.
The same blind spot applies to the other signals authors leave behind:
Same file. One agent sees a table of strings; the other sees what the author actually meant.
✨ Key Features
Image Extraction — What Makes This Different
Most Excel MCP servers only read cell values. This server uses a dual extraction strategy:
- Cell-Position Mapping (primary) — Maps each image to its exact cell location using
openpyxl-image-loader - Archive Scanning (fallback) — Scans the xlsx ZIP archive's
xl/media/directory to catch any images missed by method 1
The result: zero images left behind, with position metadata when available.
👀 See It In Action
A requirements spec where the workflow lives in a pasted diagram and the status lives in cell colors:
You: Review this spec and tell me which features are still in scope, and how the dispatch flow works.
read_full_content returns the sheet as text with formatting markers, then the embedded diagram as an image:
The model can now answer both halves of the question: "Legacy CSV export is struck through and marked cancelled, so three features remain in scope — and the flowchart in B12 shows dispatch requires roll-call confirmation before assignment."
Without image support, the second half is unanswerable. Without formatting, the cancelled row looks identical to the active ones.
🚀 Quick Start
Install via uvx (Recommended)
No installation needed — runs directly:
Install via pip
Then run:
Install from source
Run with Docker
The server speaks JSON-RPC over stdin/stdout, so it must run attached (-i). Mount the directory holding your files and reference them by their in-container path (/data/report.xlsx). The image sets EXCEL_VISION_MCP_ALLOWED_DIRS=/data, so reads and writes stay inside the mount.
As an MCP client config:
🔧 Configuration
Add the server to your MCP client's configuration file.
Claude Desktop
Edit ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):
Cursor
Edit .cursor/mcp.json in your project root:
Windsurf / VS Code (Copilot)
Edit your MCP settings file:
Antigravity IDE
Edit ~/.gemini/config/mcp_config.json:
Note: After editing the config, restart your IDE/client to load the new server.
Restricting file access (optional)
By default the server can read/write any Excel file your user account can access. To sandbox it to specific directories, set EXCEL_VISION_MCP_ALLOWED_DIRS (multiple paths separated by : on macOS/Linux, ; on Windows):
🛠️ Available Tools
list_sheets
List all sheets with dimensions, merged cell counts, and image totals. Use this first to understand a workbook's structure.
Returns: Sheet names, row×column dimensions, data ranges, merged cell counts, total image count.
read_excel_data
Read cell data from a specific sheet with pagination support.
Returns: Cell values organized by row with coordinate labels and markers for merged cells and formatting.
Markers and a short legend appear only on sheets that actually use formatting, so plain sheets cost no extra context.
extract_images
Extract all embedded images from the workbook as base64 ImageContent.
Returns: List of ImageContent (base64) with metadata — cell position, sheet name, original dimensions.
read_full_content ⭐
The star tool. Reads ALL text data AND all embedded images in a single call. Ideal for comprehensive document analysis.
Returns: Complete workbook contents — every sheet's data as structured text (with formatting markers), followed by every embedded image with cell-position mapping.
Example use case: "Analyze this requirements document and summarize all use cases, including the workflow diagrams."
Hidden rows & columns
All read tools skip hidden rows and columns by default — an author who hid them signalled they aren't part of the content to review.
One exception: a hidden cell that a visible formula references is still returned, marked [HIDDEN-REF], because its value drives results you can see. Skipped content is always reported so nothing disappears silently:
Pass include_hidden=true to read_excel_data, read_full_content, or search_excel to read everything.
get_workbook_overview
Quick structural summary of a workbook — file size, sheet list, dimensions, image count.
search_excel
Case-insensitive text search across all cells in the workbook.
Returns: Matching cells with sheet name, coordinate, and value. Limited to 100 results.
create_excel_file
Create a new empty workbook with the sheets you name.
add_excel_sheet
Add a new empty sheet to an existing workbook.
update_excel_cells
Set individual cells by coordinate. Values starting with = are written as formulas.
Note: newly written formulas show no calculated value until the file is opened in Excel. For merged ranges, write to the top-left anchor cell.
write_excel_rows
Write a rectangular block of tabular data in one call.
insert_excel_image
Insert a local image file into a workbook, anchored at a cell.
format_excel_cells
Style a range: font, colors, borders, alignment, number formats. Only the attributes you pass are changed — existing styling is preserved.
set_excel_column_widths
Set column widths manually and/or auto-fit to content.
Auto-fit counts full-width CJK characters (日本語) as 2 units. Cells longer than
max_widthget wrap text enabled instead of stretching the column — Excel auto-expands their row heights on open.
All write tools use atomic saves: the workbook is written to a temp file and swapped into place, so a failed save never corrupts your original.
.xlsmmacros are preserved. Known openpyxl limitation: pivot tables and some complex chart features are not preserved on re-save.
⚙️ How It Works
Architecture
Data Flow & Privacy
- Your file stays on your machine. The server runs locally via
stdio— no network requests, no uploads, no cloud. - Read tools never modify your files. All image processing happens in-memory (
BytesIObuffers). Write tools change only the exact file you specify, via atomic saves (temp file + swap) that can never leave a half-written workbook. - Optional directory sandbox. Set
EXCEL_VISION_MCP_ALLOWED_DIRS(path-separator-separated list) to restrict which directories the server may read or write. Unset = no restriction. - Memory is freed automatically. After each request, Python's garbage collector reclaims all buffers.
Image Processing Pipeline
📋 Supported Formats
Image Types
📊 Performance
Tested on real-world enterprise Excel files (macOS, Apple Silicon):
❓ FAQ
Why can't it extract images from .xls files?
.xls is the legacy binary format (Excel 97-2003). It uses a completely different internal structure (BIFF) compared to .xlsx (ZIP-based Open XML). The libraries used (openpyxl, openpyxl-image-loader) only support the modern Open XML format. If you have .xls files, convert them to .xlsx using Excel or LibreOffice first.
Why are some images marked as "orphan"?
The primary extraction method (openpyxl-image-loader) maps images to specific cells but may miss images that aren't anchored to the standard drawing layer. The fallback archive scanner catches these "orphan" images from the xl/media/ directory — you get every image, just without cell-position metadata for orphans.
Can I use this with models that don't support vision?
Yes! Text data extraction works perfectly with any model. Image extraction will still return ImageContent, but text-only models will simply ignore the image data. You won't get errors.
Is my data safe?
Yes. The server runs entirely on your local machine via stdio transport. No data is sent over the network and no files are uploaded anywhere. Read tools never modify your files; write tools change only the file you explicitly target, using atomic saves so a failed write can't corrupt it. You can also sandbox the server to specific directories with the EXCEL_VISION_MCP_ALLOWED_DIRS environment variable.
How do I handle very large files (100MB+)?
The server uses read_only mode for data iteration and processes images in-memory one at a time. For extremely large files, use read_excel_data with pagination (start_row + max_rows) instead of read_full_content to control memory usage.
🗺️ Roadmap
- Write support — Create workbooks, update cells, write formulas, insert images (v1.1.0)
- Format-aware reading — Bold, strikethrough, highlights, colors; hidden-content handling (v1.2.0)
- Formula evaluation — Show formulas alongside their calculated values
- CSV/TSV support — Extend to other tabular formats
- Conditional formatting — Extract formatting rules
- Chart extraction — Render charts as images
🤝 Contributing
Contributions are welcome! Please open an issue first to discuss what you'd like to change.
📄 License
MIT — use it however you want.
Built for AI agents that need to see the whole picture, not just the text.
⭐ Star this repo if it helped you!
Source: README.md at commit 1462d4d
Tools
0Version history
1- v1.2.1LatestSep 16, 2026
Score
50% of the applicable checks met
How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.
- Reached in the last 30 days25 pts
Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.
- Auth declared10 pts
Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.
- Tools listed15 pts
Answer tools/list without a credential, or ship a package that starts in a sandbox without one.
- DescriptionRequired15 pts
- Logo10 pts
- Documentation15 pts
- License10 pts