Libreoffice Calc

MCP server for controlling LibreOffice Calc workbooks through UNO.

This project focuses on reliable spreadsheet operations against an already-open workbook, or a workbook opened explicitly by the server. It avoids silent file rewrites outside LibreOffice and provides practical tools for writing cells, ranges, hyperlinks, formatting, charts, and reusable visual templates.

Demo

The demo shows the create_gpu_purchase_dashboard_live tool rebuilding the dashboard from scratch through UNO: creating the sheet, styling and filling each section live, and adding native Calc charts, so every change is visible in LibreOffice.

A higher-quality version is available at assets/demo.mp4.

Available Tools (30)

Connection & Documents

• libreoffice_status — check the UNO connection and list open Calc workbooks.
• open_calc — open a Calc or Excel workbook through LibreOffice.
• ensure_calc_document — reuse an already-open workbook, or open it explicitly if missing.
• list_calc_documents — list Calc workbooks reachable through the UNO listener.
• list_sheets — list sheets from an open or specified workbook.
• add_sheet — add a Calc sheet if it does not already exist.
• remove_sheet — remove a sheet (refuses to delete the last sheet).
• activate_sheet — activate a sheet and select a cell for live visual workflows.

Cells & Ranges

• read_cell — read a single cell value and formula.
• write_cell — write one cell directly (strings starting with = become formulas).
• read_range — read a rectangular range, returning computed values and formulas.
• write_range — write a 2D table from a starting cell.
• get_used_range — return the used data range of a sheet (e.g. A1:H42).
• clear_range — clear cell contents in a range, preserving formatting and styles.
• find_replace — search or search-and-replace within a sheet (supports regex).

Structure

• insert_rows — insert blank rows before the given 1-based row number.
• delete_rows — delete rows starting at the given 1-based row number.
• insert_columns — insert blank columns before the given column letter.
• delete_columns — delete columns starting at the given column letter.

Formatting

• format_range — apply font, colour, size, number format, and wrap to a range.
• apply_calc_template — apply a visual template (pc_nostalgia).
• auto_fit_sheets — adjust column widths, row heights, and text wrapping.

Links

• set_hyperlink — add a Ctrl-click hyperlink to a Calc cell.
• set_internal_hyperlink — add a Ctrl-click hyperlink to another sheet/cell.
• link_url_range — convert plain-text URLs in a range into Ctrl-click hyperlinks.

Charts

• insert_chart — insert a native LibreOffice chart (bar, line, or pie) into a sheet.

Visual Verification

• capture_sheet_png — render a sheet or cell range to PNG for agent inspection (requires poppler-utils / pdftoppm).

Misc

• mcp_workflow_guidance — return the workflow contract for agents using this server.
• create_gpu_purchase_dashboard_live — build the GPU purchase dashboard through UNO for live demos (personal demo tool).
• save_document — save the Calc workbook.

Build the live GPU purchase dashboard, including charts:

create_gpu_purchase_dashboard_live(
  path="/path/to/workbook.xlsx",
  dashboard_sheet="Dashboard_live",
  recreate=true,
  pause_seconds=0.25
)

Environment Variables

All variables are optional. Defaults and auto-detection are shown below.

Variable	Default / Auto-detection	Purpose
LIBREMCP_UNO_SITE_PACKAGES	Auto-detected: globs /usr/lib/python3.*/site-packages and picks the first containing uno.py; falls back to /usr/lib/python3.14/site-packages	Path to the directory containing uno.py
LIBREMCP_SOFFICE	shutil.which("soffice") or /usr/lib/libreoffice/program/soffice	Path to the soffice executable
LIBREMCP_UNO_HOST	127.0.0.1	UNO listener host
LIBREMCP_UNO_PORT	2002	UNO listener port

Manual Start

cd /home/maxime/.local/share/mcp-libreoffice-calc
uv run python src/main.py

The server starts or joins a LibreOffice UNO listener on 127.0.0.1:2002.

Code Configuration

Example ~/.code/config.toml entry:

[mcp_servers.libreoffice_calc]
command = "uv"
args = ["run", "python", "/home/maxime/.local/share/mcp-libreoffice-calc/src/main.py"]
cwd = "/home/maxime/.local/share/mcp-libreoffice-calc"

[mcp_servers.libreoffice_calc.env]
PYTHONPATH = "/home/maxime/.local/share/mcp-libreoffice-calc/src:/usr/lib/python3.14/site-packages"

Tests

Tests run without LibreOffice or a running UNO listener:

uv run python -m pytest tests/

Notes

LibreOffice must be reachable through UNO to control an already-open workbook. The recommended flow is to call ensure_calc_document once, then use the cell, range, formatting, and link tools as needed. The capture_sheet_png tool additionally requires poppler-utils (pdftoppm) to convert the PDF export to PNG.

MCP servers load tool definitions at process startup. Restart or reload your MCP client after changing server code or configuration.

Files copied from the original base project remain covered by their original license. The main server in src/ has been rewritten for this focused Calc workflow.