spreadsheet-authoring SKILL.md skillA
spreadsheet-authoring from edbertchan/catstack is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add edbertchan/catstack/spreadsheet-authoring@git:20261001.5ffd076Pins git:20261001.5ffd076 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- edbertchan/catstack
- Path
product/skills/spreadsheet-authoring/SKILL.md- Versions recorded
- 4
- Latest version
- git:20261001.5ffd076, committed Oct 1, 2026
- First version recorded
- Sep 29, 2026
- Size
- 6,103 bytes
- Repository stars
- 6
- License
- none declared
Design scalable spreadsheet models with category-level raw data, formula- driven aggregation tables, provenance, and charts. Use when creating or restructuring Excel or Google Sheets workbooks that must grow by adding rows.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Spreadsheet authoring Build the workbook as a data pipeline, not as a decorated report: `raw observations → selector-driven aggregation table → chart` ## Raw observation contract - Keep one raw sheet per category. - Keep one numeric observation per row. - Put dates in typed `Period Start` and `Period End` columns. - Put `Average`, `Start`, `Peak`, `End`, `Low`, `High`, or similar qualifiers in a separate categorical `Observation Point` column. - Preserve the source wording in `Original Period Label` for audit, but never use that display label as the aggregation key. - When a source publishes a bounded start/end range but omits an average, a midpoint may be added only as a derived estimate: retain the source URL, label `Observation Type` as `derived estimate`, and record the formula in `Notes`. Never derive a start or end value from a peak, low, or other non-endpoint observation. - Keep geography, scope, segment, entity, metric, value, unit, source, source URL, source location, derivation method, and derived-from lineage as separate fields. - Synthetic observations may be added to the category raw sheet only when …
Read the whole file at its exact version.
How to install
mdr add edbertchan/catstack/spreadsheet-authoring@sha256:5e414be79ce2eda6The line at the top of this page pins the label git:20261001.5ffd076, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_3rvw73eppypmcffp)
1 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 4 versions of this file, between Sep 29, 2026 and Oct 1, 2026, more than one a day.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261001.5ffd076 latest | 2026-10-01 | 5ffd076 | 6,103 B | A | view · diff |
| git:20260929.dcef146 | 2026-09-29 | dcef146 | 5,557 B | A | view · diff |
| git:20260929.bf65181 | 2026-09-29 | bf65181 | 4,861 B | A | view · diff |
| git:20260929.1c55fa5 | 2026-09-29 | 1c55fa5 | 4,385 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (6103 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
edbertchan/catstack · 6 stars · license none declared · pushed 2026-10-22 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_3rvw73eppypmcffp GET https://markdownregistry.com/api/v1/resolve?ref=edbertchan/catstack/spreadsheet-authoring GET https://markdownregistry.com/api/v1/blob/5e414be79ce2eda623909b986599509b9c1b4ea3568b7630b1e869e191bf8e78
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.
More from edbertchan/catstack
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