A set of rules for working with spreadsheet files such as Excel workbooks, CSV files, and TSV files. It covers reading, editing, creating, formatting, formulas, and charts.

Use it whenever a spreadsheet is the main input or output, including cleaning data, adding columns, building calculations, formatting workbooks, or creating charts.

Spreadsheet changes can introduce broken formulas or overwrite an existing layout. These rules require checking formula errors, preserving templates, and applying consistent formatting where appropriate.

xlsx — Skill for Claude Code and Codex by ldclabs: A set of rules for working with spreadsheet files…

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/ldclabs/anda-bot/xlsx

Any agent

npx skills add ldclabs/anda-bot --skill xlsx

Clone the repo

git clone --depth 1 https://github.com/ldclabs/anda-bot

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/ldclabs/anda-bot/xlsx.svg)](https://agentmods.dev/skills/ldclabs/anda-bot/xlsx)

Your own site

<a href="https://agentmods.dev/skills/ldclabs/anda-bot/xlsx"><img src="https://agentmods.dev/badge/skills/ldclabs/anda-bot/xlsx.svg" alt="Measured on agentmods" height="20"></a>

Per session 201 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,833 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. Scan, not verified.

Origin 92% 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.

Model	Per session	Once invoked
Fable 5	$0.00201	$0.02833
Opus 5	$0.00101	$0.01417
Sonnet 5	$0.00040	$0.00567
Haiku 4.5	$0.00020	$0.00283

Measured 3d ago against content hash 9db7d75a63c6, 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 3d 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.

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

92% identical to xlsx — 22 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.

skills/xlsx/SKILL.md · 292 lines

How it starts

The opening of the file, as written. The whole thing — 292 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Requirements for Outputs

All Excel files

Professional Font

Use a consistent, professional font (e.g., Arial, Times New Roman) for all deliverables unless otherwise instructed by the user

Zero Formula Errors

Every Excel model MUST be delivered with ZERO formula errors (#REF!, #DIV/0!, #VALUE!, #N/A, #NAME?)

Preserve Existing Templates (when updating templates)

Study and EXACTLY match existing format, style, and conventions when modifying files
Never impose standardized formatting on files with established patterns
Existing template conventions ALWAYS override these guidelines

Financial models

Color Coding Standards

Unless otherwise stated by the user or existing template

Industry-Standard Color Conventions

Blue text (RGB: 0,0,255): Hardcoded inputs, and numbers users will change for scenarios
Black text (RGB: 0,0,0): ALL formulas and calculations
Green text (RGB: 0,128,0): Links pulling from other worksheets within same workbook
Red text (RGB: 255,0,0): External links to other files
Yellow background (RGB: 255,255,0): Key assumptions needing attention or cells that need to be updated

Number Formatting Standards

Required Format Rules

Years: Format as text strings (e.g., "2024" not "2,024")
Currency: Use $#,##0 format; ALWAYS specify units in headers ("Revenue ($mm)")
Zeros: Use number formatting to make all zeros "-", including percentages (e.g., "$#,##0;($#,##0);-")
Percentages: Default to 0.0% format (one decimal)
Multiples: Format as 0.0x for valuation multiples (EV/EBITDA, P/E)
Negative numbers: Use parentheses (123) not minus -123

Formula Construction Rules

Assumptions Placement

Place ALL assumptions (growth rates, margins, multiples, etc.) in separate assumption cells
Use cell references instead of hardcoded values in formulas
Example: Use =B5*(1+$B$6) instead of =B5*1.05

Formula Error Prevention

Verify all cell references are correct
Check for off-by-one errors in ranges
Ensure consistent formulas across all projection periods
Test with edge cases (zero values, negative numbers)
Verify no unintended circular references

Read the full file on GitHub · 292 lines

Files

What ships with it

53 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.

3d ago First seen · 292 lines · 201 tokens per session scan A 9db7d75a63c6

Subscribe to this mod's changes

xlsx is a skill published in the GitHub repository ldclabs/anda-bot (23 stars, last pushed 26d ago), licensed Apache-2.0. It adds 201 tokens to every session and 2,833 once invoked, about $0.0010 per session on Opus 5. A static security scan graded it A with 0 findings. It is 92% identical to xlsx, differing in 22 lines, and is treated as a copy.

Documents Spreadsheets

xlsx-author

Produce a .xlsx file on disk (headless) instead of driving a live Excel workbook — for managed-agent sessions with no open Office app.

anthropics/financial-services · 32 tokens

audit-xls

Audit a spreadsheet for formula accuracy, errors, and common mistakes. Scopes to a selected range, a single sheet, or the entire model (including financial-model integrity checks like BS balance, cash tie-out, and logic sanity). Triggers on "audit this sheet", "check my formulas", "find formula errors", "QA this…

anthropics/financial-services · 104 tokens

xlsx