What is hello-world-skill?

A small Agent Skill that creates or updates a file named hello-world.txt with a fixed greeting and then verifies the file.

Use it when demonstrating or testing how an instruction-only Agent Skill performs a simple file task.

It provides a minimal example of a skill with clear instructions and an explicit verification step.

hello-world-skill — Skill for Claude Code and Codex by zuharz

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 zuharz/ccode-to-codex --skill hello-world-skill

Clone the repo

git clone --depth 1 https://github.com/zuharz/ccode-to-codex

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/zuharz/ccode-to-codex/hello-world-skill/github.svg)](https://agentmods.dev/skills/zuharz/ccode-to-codex/hello-world-skill)

Your own site

<a href="https://agentmods.dev/skills/zuharz/ccode-to-codex/hello-world-skill"><img src="https://agentmods.dev/badge/skills/zuharz/ccode-to-codex/hello-world-skill/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/zuharz/ccode-to-codex/hello-world-skill"><img src="https://agentmods.dev/badge/skills/zuharz/ccode-to-codex/hello-world-skill.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 32 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 152 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

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.

Model	Per session	Once invoked
Fable 5.1	$0.00032	$0.00152
Opus 5.5	$0.00013	$0.00061
Sonnet 5.5	$0.00006	$0.00030
Haiku 4.5	$0.00003	$0.00015

Measured 2mo ago against content hash 8ad88e53b499, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

hello-world-skill 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 2mo 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/SKILL.md · 27 lines

What it actually says

Hello World Skill

Use this skill to create or update one file with a fixed greeting and verify the result.

Steps

Inspect the current directory enough to avoid overwriting unrelated work.
Create or update hello-world.txt with exactly:
```
Hello from Codex.
```
Read hello-world.txt and verify that its content matches exactly.
Report the changed file and verification result.

Output

Return a short final response naming hello-world.txt and confirming the verification result.

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.

2mo ago First seen · 27 lines · 32 tokens per session scan A 8ad88e53b499

Subscribe to this mod's changes

hello-world-skill is a skill published in the GitHub repository zuharz/ccode-to-codex (76 stars, last pushed 2mo ago), licensed MIT. It adds 32 tokens to every session and 152 once invoked, about $0.0001 per session on Opus 5.5. 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.

hello-world-skill next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
hello-world-skillzuharz/ccode-to-codex	Skill	76	2mo ago	MIT	A	32	Claude Code, Codex
imagegenopenai/codex	Skill	133k	yesterday	Apache-2.0	A	113	Codex
playwright-climicrosoft/playwright	Skill	99k	yesterday	Apache-2.0	A	19	Claude Code
local-ai-agentsmicrosoft/ai-agents-for-beginners	Skill	79k	4d ago	MIT	A	200	Claude Code, Codex
systematic-debuggingobra/superpowers	Skill	313k	3d ago	MIT	A	21	Claude Code
next-cache-components-adoptionvercel/next.js	Skill	143k	today	MIT	A	95	Claude Code
next-partial-prefetching-adoptionvercel/next.js	Skill	143k	today	MIT	A	103	Claude Code