hs

A safety skill for reviewing shell commands and file reads before they run. It covers commands such as curl, rm, sudo, cloud tools, and shell wrappers, including commands piped to a shell.

In plain words
What is it for?
Use it whenever an agent is about to run a shell command or read a file.
Why use it?
It adds checks before operations that could download, delete, modify, or administer systems.

Skill for Claude CodeCodex

Part of the hs plugin — 1 skill, 6 commands, 1 hook shipped together

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/frmoretto/hardstop/hs
Any agent
npx skills add frmoretto/hardstop --skill hs
Clone the repo
git clone --depth 1 https://github.com/frmoretto/hardstop

Made for: Claude Code, Codex.

Or install hs, the plugin that ships this one along with the rest of its 1 skill, 6 commands, 1 hook.

Per session 144 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,699 The whole file, excluding the scripts and references it only reads on demand.
Security scan F 6 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 $0.00144 $0.05699
Opus 5 $0.00072 $0.02849
Sonnet 5 $0.00029 $0.01140
Haiku 4.5 $0.00014 $0.00570

Measured 3d ago against content hash 82bfcc35362c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade F, and why

hs scanned grade F with 6 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 3d 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.

Sends data to an external URLmediumData exfiltration

A POST to an outside endpoint may be telemetry or may be exfiltration; either way the mod talks to somewhere, and you should know where.

| `curl -d @~/.ssh/` | Exfiltrates SSH keys |

Asks for rootmediumPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

| `sudo rm -rf /` | Privileged system destruction |

Reaches for credential fileshighPrivilege escalation

SSH keys, cloud credentials, git-credentials, .npmrc, /etc/shadow: reading these is how a config file becomes a credential leak.

| Credentials in requests | `curl -d "$(cat ~/.ssh/id_rsa)"` | BLOCK |

Downloads and executes remote codehighSupply chain

curl | sh runs whatever the server returns today, which is not necessarily what it returned when this was reviewed.

| `curl/wget ... \| bash` | Executes untrusted remote code |

Recursive force deletehighDestructive command

rm -rf with a variable or a broad path is one typo away from removing the wrong tree.

| `rm -rf ~/` or `rm -rf ~/*` | Deletes entire home directory |

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

description: "ACTIVATE THIS SKILL FOR ANY SHELL COMMAND OR FILE READ. Check curl, wget, rm, sudo, apt, dpkg, chmod, dd, format, powershell, bash, sh. Check pipe patterns like | sh or | bash. Check shell wrappers like bas
.claude/skills/hs/SKILL.md · 589 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. 3d ago First seen · 589 lines · 144 tokens per session scan F 82bfcc35362c

Subscribe to this mod's changes

hs is a skill published in the GitHub repository frmoretto/hardstop (31 stars, last pushed 4mo ago), with no licence file. It adds 144 tokens to every session and 5,699 once invoked, about $0.0007 per session on Opus 5. A static security scan graded it F with 6 findings (sends data to an external url, asks for root, reaches for credential files). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.