shell-safety

shell-safety is a skill for Claude Code from buriedsignals/spotlight. It costs 35 tokens per session (630 once invoked), scanned A, original, no licence file.

A safety guide for constructing portable shell commands when values come from users, models, scraped data, configuration, filesystems, or generated content. Shell commands are instructions run by an operating system’s command interpreter.

In plain words
What is it for?
Use it before shell calls that include user-provided, model-generated, scraped, configured, filesystem-derived, or generated values.
Why use it?
It helps reduce command-construction risks when untrusted or variable text is inserted into shell calls.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the spotlight plugin — 25 skills, 2 agents shipped together

Good fit Use it before shell calls that include user-provided, model-generated, scraped, configured, filesystem-derived, or generated values.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/buriedsignals/spotlight/shell-safety
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 buriedsignals/spotlight --skill shell-safety
Clone the repo
git clone --depth 1 https://github.com/buriedsignals/spotlight

Made for: Claude Code.

Or install spotlight, the plugin that ships this one along with the rest of its 25 skills, 2 agents.

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 shell-safety

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

Your own site · 80×15
<a href="https://agentmods.dev/skills/buriedsignals/spotlight/shell-safety"><img src="https://agentmods.dev/badge/skills/buriedsignals/spotlight/shell-safety.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 35 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 630 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.
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 $0.00035 $0.00630
Opus 5 $0.00017 $0.00315
Sonnet 5 $0.00007 $0.00126
Haiku 4.5 $0.00003 $0.00063

Measured 9d ago against content hash 31818212a7fe, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

shell-safety scanned grade A with 1 finding 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.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/shell_safe.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Makes network callslowCapability

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

curl "https://example.test?q={user_query}"
plugins/spotlight/skills/shell-safety/SKILL.md · 71 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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 · 35 tokens per session scan A 31818212a7fe

Subscribe to this mod's changes

shell-safety is a skill published in the GitHub repository buriedsignals/spotlight (39 stars, last pushed 5d ago), with no licence file. It adds 35 tokens to every session and 630 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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