agentmods.dev

xlsx

xlsx is a skill for Claude Code, Codex from A3RDLab/LLM-dev-demo. It costs 206 tokens per session (2,137 once invoked), scanned A, a copy of xlsx, Apache-2.0.

A set of instructions for creating, reading, editing, and checking spreadsheet files such as Excel workbooks, CSV files, and TSV files.

In plain words
What is it for?
Updating existing spreadsheets, creating new ones, analyzing data, adding formulas or charts, and converting between supported tabular formats.
Why use it?
It provides a consistent approach for spreadsheet work, including formulas, formatting, data cleanup, and checking for formula errors.

Skill for Claude CodeCodex

not rated 44 12d ago A scan 206 tokens copy · 84% Apache-2.0
View the source file A3RDLab/LLM-dev-demo
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/a3rdlab/llm-dev-demo/xlsx
Any agent
npx skills add A3RDLab/LLM-dev-demo --skill xlsx
Clone the repo
git clone --depth 1 https://github.com/A3RDLab/LLM-dev-demo

Made for: Claude Code, Codex.

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.

agentmods badge for xlsx

README.md
[![agentmods](https://agentmods.dev/badge/skills/a3rdlab/llm-dev-demo/xlsx.svg)](https://agentmods.dev/skills/a3rdlab/llm-dev-demo/xlsx)
Your own site
<a href="https://agentmods.dev/skills/a3rdlab/llm-dev-demo/xlsx"><img src="https://agentmods.dev/badge/skills/a3rdlab/llm-dev-demo/xlsx.svg" alt="Measured on agentmods" height="20"></a>
Per session 206 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,137 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 84% copy Near-identical to another mod 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.

ModelPer sessionOnce invoked
Fable 5 $0.00206 $0.02137
Opus 5 $0.00103 $0.01069
Sonnet 5 $0.00041 $0.00427
Haiku 4.5 $0.00021 $0.00214

Measured 5d ago against content hash 6712b39718fe, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

xlsx scanned grade A with 0 findings 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 12 executable files (scripts/office/helpers/__init__.py, scripts/office/helpers/pptx_chart.py, scripts/office/helpers/pptx_slide.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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

84% identical to xlsx — 15 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

function_call_and_agent_demo/agent_harness_demo/skills/xlsx/SKILL.md · 100 lines

How it starts

The opening of the file, as written. The whole thing — 100 lines — stays where its author put it; the contents beside it link to each section on GitHub.

XLSX creation, editing, and analysis

Task Approach
Create or edit with formulas/formatting openpyxl — see gotchas below
Bulk data in or out pandas (read_excel, to_excel)
Quick look at a sheet markitdown file.xlsx — ## SheetName per sheet; reads .xlsm too. No cell coordinates, so don't plan edits from it
Read a model (formulas and values) two load_workbook passes — see gotchas

openpyxl, pandas, and markitdown are preinstalled — do not run pip install first; write the script and import directly. Only if an import fails (or the markitdown command is missing): pip install the missing package.

Script paths below are relative to this skill's directory.

Requirements for every output

  • Professional font (Arial, Times New Roman) throughout, unless the user says otherwise.
  • Zero formula errors. Never ship while recalc.py reports errors_found. If you think an error predates you, prove it: load the original with data_only=True and look at that cell. An error you introduced looks exactly like one you inherited.
  • Use formulas, never hardcoded results. Write sheet['B10'] = '=SUM(B2:B9)', not the Python-computed total. The sheet must recalculate when its inputs change.
  • Follow the user's spec literally. Exact tab names, exact column headers, and the formula they spelled out. A redesign that computes something else fails, however elegant.
  • Document every assumption and hardcoded number where the reader will see it — a cell comment, or an adjacent cell at a table's end. Cite a real source when one exists (Source: Company 10-K, FY2024, Page 45, Revenue Note, [SEC EDGAR URL]); when the number came from the user, say so plainly.
  • A workbook you create for someone to fill in needs a short legend naming which cells to edit, and one example row of realistic values showing the expected format. Never add such a row to a file you were asked to edit.
  • Editing an existing file: match its conventions exactly. They override every guideline here. Find its designated input cells first — a distinct font color, fill, or shading marks them — write only there, and leave every existing formula untouched.

Read the full file on GitHub · 100 lines

Files

What ships with it

52 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.

  1. 5d ago First seen · 100 lines · 206 tokens per session scan A 6712b39718fe

Subscribe to this mod's changes

xlsx is a skill published in the GitHub repository A3RDLab/LLM-dev-demo (44 stars, last pushed 12d ago), licensed Apache-2.0. It adds 206 tokens to every session and 2,137 once invoked, about $0.0010 per session on Opus 5. A static security scan graded it A with 0 findings. It is 84% identical to xlsx, differing in 15 lines, and is treated as a copy.

DocumentsLLMSpreadsheetsai-agentsfunction-callingmcp
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