What is Spreadsheets?

A set of instructions for creating, editing, analyzing, and checking spreadsheet files such as XLSX, CSV, TSV, and XLS.

Use it to build or modify workbooks, analyze tabular data, recalculate formulas, format sheets, and create in-sheet visualizations.

It gives spreadsheet work a consistent process for formulas, formatting, calculations, tables, and charts, including files prepared for Google Sheets.

Spreadsheets — Skill by zm1990s

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/zm1990s/kb-agent/spreadsheets

Any agent

npx skills add zm1990s/kb-agent --skill spreadsheets

Clone the repo

git clone --depth 1 https://github.com/zm1990s/kb-agent

Made for: Claude Code, Codex.

Per session 52 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 3,213 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. Scan, not verified.

Origin 88% 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	$0.00052	$0.03213
Opus 5	$0.00026	$0.01606
Sonnet 5	$0.00010	$0.00643
Haiku 4.5	$0.00005	$0.00321

Measured 2d ago against content hash 98c8106e5f0d, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

Spreadsheets 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 2d ago.

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

88% identical to Spreadsheets — 403 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.

backend/codex_skills/spreadsheets/SKILL.md · 210 lines

How it starts

The opening of the file, as written. The whole thing — 210 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Spreadsheets skill (Create • Edit • Analyze • Visualize)

Use this skill when you need to work with spreadsheets (.xlsx, .csv, .tsv) to do any of the following:

Create or modify a new workbook/sheet with proper formulas, cell/number formatting, and structured layout
Read or analyze tabular data (filter, aggregate, pivot, compute metrics) directly in a sheet
Visualize data with in-sheet charts/tables and sensible formatting
Recalculate/evaluate formulas to update results after changes

Decision Boundary

For Google Sheets-targeted outputs, such as creating or editing a Google Sheet, follow the additional instructions here: routing/google_sheets.md.

Do not follow those routing instructions if irrelevant to the task. Default is to create/edit spreadsheets with artifact tool.

Tools + Contract Requirements

Use @oai/artifact-tool JS library for all spreadsheet authoring, using only the executables and dependency paths provided by load_workspace_dependencies. Do not use system, global, or repo-local dependencies.
If the runtime or @oai/artifact-tool is unavailable, report a blocker. Do not guess or search for paths, install packages, use resolution hacks, or import bundled internals.
Work in a writable, conversation-specific or tmp directory. In that working directory, create a node_modules symlink or Windows junction pointing to the loader-provided node_modules directory. Never modify the loader-provided dependency directory.
Prefer one executable .mjs builder and patch/rerun it. Do not use heredocs or duplicate builders.
Use the provided API reference. Do not inspect package internals or prototypes. If blocked, run at most one targeted workbook.help("<api_or_feature>") query.
Do not use alternate workbook creation/editing libraries such as openpyxl, xlsxwriter, or pandas.ExcelWriter unless the user explicitly asks.
For supporting analysis or data processing outside workbook authoring, use JS or spreadsheet formulas when sufficient. If Python is necessary, prefer the bundled python libraries, save JSON/CSV intermediates, and have the JS builder create the workbook. Use existing system Python or user-provided libraries only when the bundled environment lacks a required capability. Keep auditable and user-editable calculations in the workbook as formulas.
Use update_plan for complex spreadsheet work.

Read the full file on GitHub · 210 lines

Files

What ships with it

11 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.

2d ago First seen · 210 lines · 52 tokens per session scan A 98c8106e5f0d

Subscribe to this mod's changes

Spreadsheets is a skill published in the GitHub repository zm1990s/kb-agent (5 stars, last pushed 12d ago), licensed MIT. It adds 52 tokens to every session and 3,213 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 88% identical to Spreadsheets, differing in 403 lines, and is treated as a copy.

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