convert-file

convert-file is a skill for Claude Code from duckdb/duckdb-skills. It costs 94 tokens per session (823 once invoked), scanned A, original, MIT.

A data-file conversion skill that changes files between formats such as CSV, Parquet, JSON, Excel, and geospatial formats using DuckDB, a tool for querying and exporting data.

In plain words
What is it for?
Use it to turn files into formats such as Parquet, CSV, TSV, JSON, XLSX, GeoJSON, GeoPackage, or Shapefile.
Why use it?
It removes the need to write separate conversion code for each supported format and helps avoid guessing the output settings.

Skill for Claude Code ✓ vendor

Written for Claude Code: allowed-tools in frontmatter. Also seen: positional $N argument.

Part of the duckdb-skills plugin — 9 skills shipped together

not rated 539repo +1 4mo ago A scan Socket: passSnyk: warnSkillSpector: pass 94 tokens original MIT

Good fit Use it to turn files into formats such as Parquet, CSV, TSV, JSON, XLSX, GeoJSON, GeoPackage, or Shapefile.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/duckdb/duckdb-skills/convert-file
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.

Any agent
npx skills add duckdb/duckdb-skills --skill convert-file
Clone the repo
git clone --depth 1 https://github.com/duckdb/duckdb-skills

Made for: Claude Code.

Or install duckdb-skills, the plugin that ships this one along with the rest of its 9 skills.

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.

agentmods badge for convert-file

README.md
[![agentmods](https://agentmods.dev/badge/skills/duckdb/duckdb-skills/convert-file/github.svg)](https://agentmods.dev/skills/duckdb/duckdb-skills/convert-file)
Your own site
<a href="https://agentmods.dev/skills/duckdb/duckdb-skills/convert-file"><img src="https://agentmods.dev/badge/skills/duckdb/duckdb-skills/convert-file/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.

agentmods 80×15 button for convert-file

Your own site · 80×15
<a href="https://agentmods.dev/skills/duckdb/duckdb-skills/convert-file"><img src="https://agentmods.dev/badge/skills/duckdb/duckdb-skills/convert-file.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 94 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 823 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • Socket pass 14 Apr 2026
  • Snyk warn 14 Apr 2026
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00094 $0.00823
Opus 5 $0.00047 $0.00411
Sonnet 5 $0.00019 $0.00165
Haiku 4.5 $0.00009 $0.00082

Measured 9d ago against content hash f60b4b0c136e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

convert-file 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 9d 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.

skills/convert-file/SKILL.md · 71 lines

How it starts

The opening of the file, as written. The whole thing — 71 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are helping the user convert a data file from one format to another using DuckDB.

Input file: $0 Output file: ${1:-}

Step 1 — Resolve input and output

Input: $0. If it's a bare filename (no /), resolve to a full path with find "$PWD" -name "$0" -not -path '*/.git/*' 2>/dev/null | head -1.

Output: If $1 is provided, use it as the output path. If not, default to the same stem as the input with a .parquet extension (e.g., data.csvdata.parquet).

Infer the output format from the output file extension:

Extension Format clause
.parquet, .pq (default, no clause needed)
.csv (FORMAT csv, HEADER)
.tsv (FORMAT csv, HEADER, DELIMITER '\t')
.json (FORMAT json, ARRAY true)
.jsonl, .ndjson (FORMAT json, ARRAY false)
.xlsx (FORMAT xlsx) — requires INSTALL excel; LOAD excel;
.geojson (FORMAT GDAL, DRIVER 'GeoJSON') — requires LOAD spatial;
.gpkg (FORMAT GDAL, DRIVER 'GPKG') — requires LOAD spatial;
.shp (FORMAT GDAL, DRIVER 'ESRI Shapefile') — requires LOAD spatial;

Step 2 — Convert

Run a single DuckDB command. Prepend extension loads as needed based on both the input and output formats.

duckdb -c "
<EXTENSION_LOADS>
COPY (FROM '<INPUT_PATH>') TO '<OUTPUT_PATH>' <FORMAT_CLAUSE>;
"

For remote inputs (s3://, https://, etc.), prepend the same protocol setup as read-file:

Protocol Prepend
s3:// LOAD httpfs; CREATE SECRET (TYPE S3, PROVIDER credential_chain);
gs:// / gcs:// LOAD httpfs; CREATE SECRET (TYPE GCS, PROVIDER credential_chain);
https:// / http:// LOAD httpfs;

If the user mentions partitioning (e.g., "partition by year"), add PARTITION_BY (col) to the format clause. This only works with Parquet and CSV output.

If the user mentions compression (e.g., "use zstd"), add CODEC 'zstd' for Parquet output.

Step 3 — Report

On success, report:

  • Input file and detected format
  • Output file, format, and size (ls -lh)
  • Row count if quick to compute

Read the full file on GitHub · 71 lines

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.

  1. 9d ago First seen · 71 lines · 94 tokens per session scan A f60b4b0c136e

Subscribe to this mod's changes

convert-file is a skill published in the GitHub repository duckdb/duckdb-skills (539 stars, last pushed 4mo ago), licensed MIT. It adds 94 tokens to every session and 823 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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