hello-world

hello-world is a skill for Claude Code, Codex from yurakawa/mskills. It costs 22 tokens per session (50 once invoked), scanned A, original, MIT.

A small example of an agent skill that says hello and shows a basic skill structure. It is intended as a learning example rather than a domain-specific tool.

In plain words
What is it for?
Use it to study the structure of a simple skill or as a starting point for creating your own.
Why use it?
It gives you a minimal reference when learning how agent skills can be organized and configured.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to study the structure of a simple skill or as a starting point for creating your own.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/yurakawa/mskills/hello-world
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 yurakawa/mskills --skill hello-world
Clone the repo
git clone --depth 1 https://github.com/yurakawa/mskills

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 hello-world

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

Your own site · 80×15
<a href="https://agentmods.dev/skills/yurakawa/mskills/hello-world"><img src="https://agentmods.dev/badge/skills/yurakawa/mskills/hello-world.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 22 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 50 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.
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 $0.00022 $0.00050
Opus 5 $0.00011 $0.00025
Sonnet 5 $0.00004 $0.00010
Haiku 4.5 $0.00002 $0.00005

Measured 8d ago against content hash 0c76be71e4b0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

hello-world 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 8d 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.

examples/hello-world/SKILL.md · 8 lines

What it actually says

Hello World Skill

This is a sample skill managing some basic configuration files or scripts.

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. 8d ago First seen · 8 lines · 22 tokens per session scan A 0c76be71e4b0

Subscribe to this mod's changes

hello-world is a skill published in the GitHub repository yurakawa/mskills (3 stars, last pushed 4mo ago), licensed MIT. It adds 22 tokens to every session and 50 once invoked, about $0.0001 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.

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