shell-sandbox

shell-sandbox is a skill for Claude Code, Codex from seamus-brady/springdrift. It costs 22 tokens per session (280 once invoked), scanned A, original, AGPL-3.0.

A skill for running shell commands inside a restricted Docker container with the project directory available at /workspace. A shell is a text-based way to run operating-system commands.

In plain words
What is it for?
Use it when a coding agent needs to inspect files or run project commands in the provided sandbox.
Why use it?
It provides a separated environment for command-line work, which can limit the effect of those commands on the surrounding computer.

Skill for Claude CodeCodex

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/seamus-brady/springdrift/shell-sandbox
Any agent
npx skills add seamus-brady/springdrift --skill shell-sandbox
Clone the repo
git clone --depth 1 https://github.com/seamus-brady/springdrift

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 shell-sandbox

README.md
[![agentmods](https://agentmods.dev/badge/skills/seamus-brady/springdrift/shell-sandbox.svg)](https://agentmods.dev/skills/seamus-brady/springdrift/shell-sandbox)
Your own site
<a href="https://agentmods.dev/skills/seamus-brady/springdrift/shell-sandbox"><img src="https://agentmods.dev/badge/skills/seamus-brady/springdrift/shell-sandbox.svg" alt="Measured on agentmods" 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 280 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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 $0.00022 $0.00280
Opus 5 $0.00011 $0.00140
Sonnet 5 $0.00004 $0.00056
Haiku 4.5 $0.00002 $0.00028

Measured 5d ago against content hash 699fcb6ba7d5, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

shell-sandbox 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 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.

Makes network callslowCapability

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

- Available tools: bash, curl, wget, git, python3, pip, jq, ripgrep, fd
.springdrift_example/skills/shell-sandbox/SKILL.md · 30 lines

The source is not reproduced here

Licensed AGPL-3.0

The repository is licensed AGPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

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 · 30 lines · 22 tokens per session scan A 699fcb6ba7d5

Subscribe to this mod's changes

shell-sandbox is a skill published in the GitHub repository seamus-brady/springdrift (46 stars, last pushed 4mo ago), licensed AGPL-3.0. It adds 22 tokens to every session and 280 once invoked, about $0.0001 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.