csv:merge

csv:merge is a skill for Claude Code, Codex from belarusrulez/skill-core. It costs 42 tokens per session (406 once invoked), scanned A, original, no licence file.

A tool for combining two or more CSV files, which are tables stored as text, using a shared key column. It creates one deduplicated table by keeping matching and non-matching rows from all files.

In plain words
What is it for?
Use it to join related CSV exports into a file or send the combined table to standard output.
Why use it?
It avoids manually copying rows between files and preserves records that appear in only one source.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing.

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/belarusrulez/skill-core/csv-merge
Any agent
npx skills add belarusrulez/skill-core --skill csv-merge
Clone the repo
git clone --depth 1 https://github.com/belarusrulez/skill-core

Made for: Claude Code, Codex.

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 csv:merge

README.md
[![agentmods](https://agentmods.dev/badge/skills/belarusrulez/skill-core/csv-merge.svg)](https://agentmods.dev/skills/belarusrulez/skill-core/csv-merge)
Your own site
<a href="https://agentmods.dev/skills/belarusrulez/skill-core/csv-merge"><img src="https://agentmods.dev/badge/skills/belarusrulez/skill-core/csv-merge.svg" alt="Measured on agentmods" height="20"></a>
Per session 42 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 406 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00042 $0.00406
Opus 5 $0.00021 $0.00203
Sonnet 5 $0.00008 $0.00081
Haiku 4.5 $0.00004 $0.00041

Measured 5d ago against content hash fd155dc56389, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

csv:merge 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 5d 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.

test/skills/csv-merge/SKILL.md · 22 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

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. 5d ago First seen · 22 lines · 42 tokens per session scan A fd155dc56389

Subscribe to this mod's changes

csv:merge is a skill published in the GitHub repository belarusrulez/skill-core (2 stars, last pushed 3mo ago), with no licence file. It adds 42 tokens to every session and 406 once invoked, about $0.0002 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 2026-08-31.