A toolkit for working with spreadsheet files such as Excel workbooks, CSV files, and tab-separated files. It supports creating, editing, checking, and analyzing spreadsheet data.

Use it to create or modify workbooks, convert CSV or TSV data to Excel, analyze tables, apply formatting, add charts, and recalculate or check formulas.

It helps automate spreadsheet tasks that are slow or error-prone by hand, including cleaning data, changing formats, adding formulas, and detecting calculation problems.

xlsx — Skill for Claude Code by desirecore: A toolkit for working with spreadsheet files such as…

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods

npx agentmods add skills/desirecore/market/xlsx

Any agent

npx skills add desirecore/market --skill xlsx

Clone the repo

git clone --depth 1 https://github.com/desirecore/market

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/desirecore/market/xlsx.svg)](https://agentmods.dev/skills/desirecore/market/xlsx)

Your own site

<a href="https://agentmods.dev/skills/desirecore/market/xlsx"><img src="https://agentmods.dev/badge/skills/desirecore/market/xlsx.svg" alt="Measured on agentmods" height="20"></a>

Per session 235 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 4,617 The whole file, excluding the scripts and references it only reads on demand.

Security scan B 1 finding. Scan, not verified.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00235	$0.04617
Opus 5	$0.00118	$0.02308
Sonnet 5	$0.00047	$0.00923
Haiku 4.5	$0.00023	$0.00462

Measured 5d ago against content hash db72af16cce6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade B, and why

xlsx scanned grade B with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

The scan reads SKILL.md. This mod also ships 13 executable files (scripts/office/helpers/__init__.py, scripts/office/helpers/merge_runs.py, scripts/office/helpers/simplify_redlines.py, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Asks for rootmediumPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

- **Linux (Debian/Ubuntu)**: `sudo apt install python3 python3-pip`

skills/xlsx/SKILL.md · 432 lines

How it starts

The opening of the file, as written. The whole thing — 432 lines — stays where its author put it; the contents beside it link to each section on GitHub.

xlsx Skill

L0: One-line Summary

Create, edit, and analyze Excel spreadsheets (.xlsx), with support for formulas, formatting, data analysis, and visualization.

L1: Overview and Use Cases

Capability

xlsx is a Procedural Skill that provides full processing capabilities for Excel spreadsheets. Built on Python libraries (openpyxl, pandas), it supports creating new spreadsheets, editing existing files, data analysis, formula calculation, formatting, and chart generation, and uses LibreOffice for formula recalculation and error detection.

Use Cases

The user needs to create a new Excel spreadsheet (financial models, data reports, etc.)
The user needs to edit or modify an existing .xlsx file
The user needs to perform data analysis, cleaning, or format conversion (CSV/TSV → XLSX)
The user needs to add formulas, charts, or formatting to an existing spreadsheet

L2: Detailed Specification

Script Path Rule (mandatory)

The Python scripts bundled with this skill live inside the skill installation directory. You MUST use full paths when invoking them — never use bare relative paths.

The skill directory is provided by the <skill-dir> tag in the context. Prefix all scripts/ commands accordingly:

python "<skill-dir>/scripts/recalc.py" output.xlsx
python "<skill-dir>/scripts/recalc.py" output.xlsx 30

NEVER run python scripts/recalc.py directly — that relative path does not exist in the user's working directory.

Prerequisites

Python 3 (required)

Before performing any Python operation, first check whether Python is available:

python3 --version 2>/dev/null || python --version 2>/dev/null

If the command fails (Python is unavailable), you must stop and instruct the user to install Python 3:

macOS: brew install python3 or download from https://www.python.org/downloads/
Windows: winget install Python.Python.3 or download from python.org (check "Add Python to PATH" during installation)
Linux (Debian/Ubuntu): sudo apt install python3 python3-pip
Linux (Fedora/RHEL): sudo dnf install python3 python3-pip

Read the full file on GitHub · 432 lines

Files

What ships with it

54 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

5d ago First seen · 432 lines · 235 tokens per session scan B db72af16cce6

Subscribe to this mod's changes

xlsx is a skill published in the GitHub repository desirecore/market (2 stars, last pushed today), licensed MIT. It adds 235 tokens to every session and 4,617 once invoked, about $0.0012 per session on Opus 5. A static security scan graded it B with 1 finding (asks for root). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Documents Spreadsheets excel office spreadsheet xlsx

xlsx