Columnist

Data profiling skill for Claude: check and clean any CSV

Reviews

Overview Reviews Questions What’s newWrite a review

Install Columnist

Inside Claude Code2 commands, in order

>/plugin marketplace add https://vayleer.com/plugins/marketplace.json>/plugin install columnist@vayleer

Run both commands inside Claude Code. The first adds the Vayleer marketplace once; after that every plugin here installs with one command.

Sign in before you copy to get your personal command. Reviews written after a tracked install show as verified installs.Sign in

About Columnist

Columnist is a data profiling and data quality skill for Claude. Before you analyse, import or migrate a CSV, TSV or spreadsheet export, a script reads every row and reports each column's real type, blanks, ranges, outliers, mixed formats, duplicates and spreadsheet damage such as IDs turned into 8.80E+12, error cells and garbled accents.

When you want it cleaned, it drafts the rules, asks you to settle the choices that change meaning, writes a cleaned copy with a log of every change and shows what changed. A data contract learned from a good file then checks every future export, and exports as SQL or JSON Schema.

Every row profiledLarge files streamed; encoding and delimiter detected.
Spreadsheet damageLost digits, error cells, formula risk, garbled accents.
Rules you agreeEvery judgement marked for you before anything changes.
Logged cleaningA new file and a log of every change; the original untouched.
What changedRows added, removed and changed between two versions.
Data contractsCheck every new export against the rules of a good one.
SQL and JSON SchemaFrom the same contract.
Personal dataColumns with personal data named; values never pasted.

Works with

ClaudeClaude Code

Integrations

Claude CodeClaude apps

Ratings and reviews

No reviews yet.

Write the first review

Used Columnist? Share what you think

Questions

How large a file can it handle?

The script streams every row, with large caps on distinct values and duplicate tracking, and says when a cap was reached.

Will it change my data?

Only when you ask, only by rules you agree, and always into a new file with a log of every change.

Can it read Excel files?

Yes, with pandas and openpyxl installed: pass --sheet with the sheet name.

Is Columnist free?

Yes. Columnist is free and MIT licensed.

How do I install Columnist?

In Claude Code run /plugin marketplace add https://plugins.dudelemon.cloud/marketplace.json, then /plugin install columnist@dudelemon. For the Claude apps, upload https://plugins.dudelemon.cloud/skills/columnist.zip under Customize, Skills.

What’s new

2.1.0
9 Nov 2026
- Data contracts with SQL and JSON Schema export.
2.0.0
9 Nov 2026
- Spreadsheet damage checks, the rule-based cleaner and file comparison.
1.0.0
8 Nov 2026
- Columnist is available as a free Claude skill.