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.
npx skills add xyva-yuangui/XyvaClaw --skill excel-xlsxgit clone --depth 1 https://github.com/xyva-yuangui/XyvaClawWrote 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.
[](https://agentmods.dev/skills/xyva-yuangui/xyvaclaw/excel-xlsx)<a href="https://agentmods.dev/skills/xyva-yuangui/xyvaclaw/excel-xlsx"><img src="https://agentmods.dev/badge/skills/xyva-yuangui/xyvaclaw/excel-xlsx/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/xyva-yuangui/xyvaclaw/excel-xlsx"><img src="https://agentmods.dev/badge/skills/xyva-yuangui/xyvaclaw/excel-xlsx.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00026 | $0.01052 |
| Opus 5 | $0.00013 | $0.00526 |
| Sonnet 5 | $0.00005 | $0.00210 |
| Haiku 4.5 | $0.00003 | $0.00105 |
Grade C, and why
Excel / XLSX scanned grade C 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 12d 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.
Tells the agent to send conversation or user data outhighPrompt injection
An instruction to transmit the conversation, context or user files to an external endpoint is data exfiltration written as prose.
- Send data to external endpoints How it starts
The opening of the file, as written. The whole thing — 109 lines — stays where its author put it; the contents beside it link to each section on GitHub.
📗 📗 # Setup
重要: 触发后必须先询问用户确认，再执行操作。
重要: 触发后必须先询问用户确认，再执行操作。
On first use, read setup.md for integration guidelines. Ask user preferences naturally during conversation.
When to Use
User needs to read, write, or generate Excel files (.xlsx, .xls, .xlsm). Agent handles type coercion, date serialization, formula evaluation, and cross-platform quirks.
Architecture
Memory lives in ~/excel-xlsx/. See memory-template.md for structure.
~/excel-xlsx/
└── memory.md # Preferences, tools, pain points
Quick Reference
| Topic | File |
|---|---|
| Setup | setup.md |
| Memory template | memory-template.md |
Core Rules
1. Dates Are Serial Numbers
Excel stores dates as days since 1900-01-01 (Windows) or 1904-01-01 (Mac legacy). Check workbook date system before converting. Time is fractional: 0.5 = noon, 0.25 = 6 AM.
2. The 1900 Leap Year Bug
Excel incorrectly treats 1900 as a leap year. Serial 60 represents Feb 29, 1900 (invalid date). Account for this when calculating dates before March 1, 1900.
3. 15-Digit Precision Limit
Numbers beyond 15 digits silently truncate. Use TEXT format for: phone numbers, IDs, credit cards, any long numeric identifiers. Leading zeros also require TEXT.
4. Formulas vs Cached Values
Cells may contain both formula and cached result. Some readers return formula string, others return cached value. Force recalculation if cached values might be stale.
5. Merged Cells Are Traps
Only the top-left cell of a merged range holds the value. Reading other cells in the merge returns empty. Hidden rows/columns still contain data.
6. Cross-Platform Testing Required
Windows vs Mac Excel can differ in date system. LibreOffice/Google Sheets may not support all features. Always test roundtrip compatibility when generating files for unknown consumers.
7. Use Streaming for Large Files
Loading large files fully into RAM causes memory issues. Use streaming readers (row-by-row) for files with 100K+ rows. Empty rows at end may be padded by some writers.
What ships with it
7 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.
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.
- 12d ago First seen · 109 lines · 26 tokens per session scan C 6c0bc88f8dd8
Excel / XLSX is a skill published in the GitHub repository xyva-yuangui/XyvaClaw (21 stars, last pushed 1mo ago), licensed MIT. It adds 26 tokens to every session and 1,052 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it C with 1 finding (tells the agent to send conversation or user data out). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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