LibreOffice MCP Tools

[!WARNING] This project was written by GitHub Copilot and has not been fully reviewed by a human. Code may contain bugs, security issues, or unexpected behavior. Use at your own risk. Do not use in production without thorough review.

A Model Context Protocol (MCP) server that gives AI agents (Claude, Copilot, Gemini, Cursor, etc.) the ability to read, write, and edit Office documents via LibreOffice — with a token-efficient design that minimizes LLM context usage.

Inspired by the architecture of chrome-devtools-mcp.

✨ Features

• 22 MCP tools covering reading, writing, spreadsheets, and presentations
• Token-efficient design: outline-first navigation, range-based access, pagination
• Broad format support: DOCX, DOC, XLSX, XLS, PPTX, PPT, ODT, ODS, ODP, RTF, CSV, TXT, PDF
• Legacy format bridge: .doc, .xls, .ppt auto-converted via LibreOffice before parsing
• No LibreOffice required for basic reads: native parsers handle DOCX, XLSX, PPTX directly
• LibreOffice required for: legacy formats, PDF export, format conversion

📋 Supported Formats

Format	Extensions	Read	Write	Method
Word 2007+	.docx, .dotx	✅	✅	Native (mammoth read / JSZip OOXML write)
Word 97-2003	.doc, .dot	✅	✅	LibreOffice bridge
Excel 2007+	.xlsx, .xlsm	✅	✅	Native (ExcelJS)
Excel 97-2003	.xls	✅	✅	LibreOffice bridge
PowerPoint 2007+	.pptx	✅	✅	Native (JSZip OOXML)
PowerPoint 97-2003	.ppt	✅	✅	LibreOffice bridge
OpenDocument Text	.odt	✅	✅	LibreOffice bridge
OpenDocument Spreadsheet	.ods	✅	✅	LibreOffice bridge
OpenDocument Presentation	.odp	✅	✅	LibreOffice bridge
Rich Text Format	.rtf	✅	✅	LibreOffice bridge
CSV	.csv	✅	✅	Native
PDF	.pdf	✅ (text)	❌	LibreOffice CLI
Plain text	.txt	✅	✅	Native

🚀 Quick Start

Prerequisites

• Node.js 20+
• LibreOffice (optional for basic DOCX/XLSX/PPTX reads; required for .doc/.xls/.ppt and format conversion)
  • Windows: Download LibreOffice
  • macOS: brew install --cask libreoffice
  • Linux: sudo apt install libreoffice or sudo dnf install libreoffice

Installation

Using npx (recommended — no install needed):

{
  "mcpServers": {
    "libreoffice": {
      "command": "npx",
      "args": ["-y", "@passerbyflutter/libreoffice-mcp-tools"]
    }
  }
}

Global install:

npm install -g @passerbyflutter/libreoffice-mcp-tools

From source:

git clone https://github.com/passerbyflutter/libreoffice-mcp-tools
cd libreoffice-mcp-tools
npm install
npm run build

Configure your MCP client

Add to your MCP client configuration (e.g., Claude Desktop claude_desktop_config.json):

{
  "mcpServers": {
    "libreoffice": {
      "command": "npx",
      "args": ["-y", "@passerbyflutter/libreoffice-mcp-tools"],
      "env": {
        "SOFFICE_PATH": "/path/to/soffice"
      }
    }
  }
}

Or use .mcp.json at your project root:

{
  "mcpServers": {
    "libreoffice": {
      "command": "npx",
      "args": ["-y", "@passerbyflutter/libreoffice-mcp-tools"]
    }
  }
}

CLI Options

node build/bin/libreoffice-mcp.js [options]

  --libreoffice-path <path>   Path to soffice executable
                              (default: auto-detected or SOFFICE_PATH env)

🛠 Tool Reference

Document Management

Tool	Description
document_open	Open a file → returns docId handle. Auto-bridges legacy formats.
document_close	Release document handle and temp files
document_list	List all open documents
document_create	Create new empty document (writer/calc/impress)
document_save	Save to current or new path
document_export	Export via LibreOffice (PDF, HTML, CSV, etc.)
document_convert	Convert file format (DOC→DOCX, XLSX→CSV, etc.)

Reading (Token-Efficient)

Tool	Description
document_get_metadata	Title, author, word/page count, dates
document_get_outline	Headings (Writer) / sheet names (Calc) / slide titles (Impress)
document_read_text	Paginated document text as Markdown
document_read_range	Specific paragraph or slide range
document_search	Find text with surrounding context

Writing (Writer)

Tool	Description
document_insert_text	Insert at start/end/after heading
document_replace_text	Find & replace (first or all occurrences)
document_insert_paragraph	Insert paragraph at specific index
document_apply_style	Apply heading/paragraph style

Spreadsheet (Calc)

Tool	Description
spreadsheet_list_sheets	Sheet names with row/col counts
spreadsheet_get_range	Cell range as JSON + markdown table
spreadsheet_set_cell	Set cell value or formula
spreadsheet_set_range	Set 2D range of values
spreadsheet_add_sheet	Add new sheet
spreadsheet_get_formulas	Get formula expressions in range

Presentation (Impress)

Tool	Description
presentation_list_slides	Slide titles with index
presentation_get_slide	Full slide content (title, body, notes)
presentation_get_notes	Speaker notes
presentation_add_slide	Add new slide (requires LibreOffice)
presentation_update_slide	Update slide content

💡 Token-Saving Workflow

For maximum token efficiency, follow this pattern:

1. document_open(filePath) → get docId
2. document_get_metadata(docId) → understand size/type
3. document_get_outline(docId) → see structure
4. document_read_range(docId, startIndex=N, endIndex=M) → read specific section

Instead of dumping the entire document, you navigate to exactly what you need.

Spreadsheet workflow:

1. document_open(path) → docId
2. spreadsheet_list_sheets(docId) → see all sheets
3. spreadsheet_get_range(docId, sheetName="Sales", range="A1:D20") → targeted data

🏗 Architecture

src/
├── index.ts                # createMcpServer() — MCP server factory
├── LibreOfficeAdapter.ts   # soffice subprocess manager
├── DocumentContext.ts      # Open document registry
├── DocumentSession.ts      # Per-document state + format bridge
├── McpResponse.ts          # Response builder (text/JSON/markdown)
├── Mutex.ts                # Serializes LibreOffice subprocess calls
├── parsers/
│   ├── DocxParser.ts           # DOCX read → {paragraphs, outline, metadata} (mammoth)
│   ├── DocxOoxmlEditor.ts      # DOCX write → direct JSZip OOXML manipulation (format-preserving)
│   ├── XlsxParser.ts           # XLSX read/write via ExcelJS
│   ├── PptxParser.ts           # PPTX read → {slides[]} (JSZip XML)
│   └── PptxOoxmlEditor.ts      # PPTX write → add/update slides, create PPTX (JSZip OOXML)
├── formatters/
│   ├── MarkdownFormatter.ts
│   ├── JsonFormatter.ts
│   └── TableFormatter.ts   # Spreadsheet → Markdown table
└── tools/
    ├── documents.ts         # open/close/list/create
    ├── reader.ts            # metadata/outline/read/search
    ├── writer.ts            # insert/replace/style
    ├── spreadsheet.ts       # get/set cells/ranges/sheets
    ├── presentation.ts      # slides/notes
    └── converter.ts         # save/export/convert

🧪 Testing

# Create sample fixtures
node tests/create-fixtures.mjs

# Run smoke tests
npm test

📝 Environment Variables

Variable	Description
SOFFICE_PATH	Path to LibreOffice soffice executable
DEBUG	Set to lo-mcp:* for verbose logging

📄 License

MIT