A web-browsing tool that searches for information and fetches pages inside a separate Docker container. Docker is a way to run software in an isolated environment, away from your computer’s main system.

Use it for online research, web searches, and reading fetched pages when you want browsing to happen in an isolated, logged environment.

It reduces the risk of unsafe web pages affecting your machine and keeps a record of searches and URLs.

web-sandbox — Skill for Claude Code by antoniocascais

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 antoniocascais/claude-code-toolkit --skill web-sandbox

Clone the repo

git clone --depth 1 https://github.com/antoniocascais/claude-code-toolkit

Made for: Claude Code.

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/antoniocascais/claude-code-toolkit/web-sandbox/github.svg)](https://agentmods.dev/skills/antoniocascais/claude-code-toolkit/web-sandbox)

Your own site

<a href="https://agentmods.dev/skills/antoniocascais/claude-code-toolkit/web-sandbox"><img src="https://agentmods.dev/badge/skills/antoniocascais/claude-code-toolkit/web-sandbox/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/antoniocascais/claude-code-toolkit/web-sandbox"><img src="https://agentmods.dev/badge/skills/antoniocascais/claude-code-toolkit/web-sandbox.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 105 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 690 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 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.

Model	Per session	Once invoked
Fable 5.1	$0.00105	$0.00690
Opus 5.5	$0.00042	$0.00276
Sonnet 5.5	$0.00021	$0.00138
Haiku 4.5	$0.00011	$0.00069

Measured 2mo ago against content hash 6a6cddc877a4, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

web-sandbox 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.

skills/web-sandbox/SKILL.md · 62 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

Files

What ships with it

2 files 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.

2mo ago First seen · 62 lines · 105 tokens per session scan A 6a6cddc877a4

Subscribe to this mod's changes

web-sandbox is a skill published in the GitHub repository antoniocascais/claude-code-toolkit (13 stars, last pushed 3mo ago), licensed AGPL-3.0. It adds 105 tokens to every session and 690 once invoked, about $0.0004 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.

Browser automation Research

web-sandbox next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
web-sandboxantoniocascais/claude-code-toolkit	Skill	13	3mo ago	AGPL-3.0	A	105	Claude Code
interactive-loginyc-software/qm	Skill	16k	yesterday	MIT	A	46	Claude Code, Codex
pinchtab-mcppinchtab/pinchtab	Skill	11k	10d ago	MIT	A	52	Claude Code, Codex
azure-messaging-webpubsub-javamicrosoft/skills	Skill	3.2k	yesterday	MIT	A	43	Claude Code
cua-driverdavidondrej/skills	Skill	4.3k	3d ago	MIT	A	68	Claude Code, Codex
open-design-browsercompozy/compozy	Skill	2.8k	yesterday	MIT	A	56	Claude Code, Codex
southwestborski/travel-hacking-toolkit	Skill	895	yesterday	MIT	A	40	Claude Code