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@extension.dev/skill

Skill · npm · graded 2026-10-21Source linked

Agent Skill that teaches AI coding agents (Claude Code, Cursor, Copilot, Codex) to build, debug, and publish browser extensions for Chrome, Edge, Firefox, Safari, and every Chromium- or Gecko-based browser (Brave, Opera, Vivaldi, Yandex, Waterfox, Zen, Fl

No outside reports on file

@extension.dev/skill fetches arbitrary web URLs; restrict its folder reach, network access, and credentials before installing.

Based on public adoption and transparency signals as of Oct 21, 2026. Our opinion, not a code audit or security guarantee.

Was this verdict for @extension.dev/skill helpful?

What it can access

  • Local filesNo local folder access notedLOW
  • Command executionNo shell command runner notedLOW
  • Network reachFetches arbitrary web URLsREVIEW
  • CredentialsNo API token requiredLOW
  • Package sourcenpm (@extension.dev/skill)PUBLIC

Inferred from this listing’s public package details and description. Check the project’s source before installing.

Install

npx -y @extension.dev/skill

All setup options ↓

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About @extension.dev/skill

@extension.dev/skill is an agent skill focused on Developer tools and Web & browsing: Agent Skill that teaches AI coding agents (Claude Code, Cursor, Copilot, Codex) to build, debug, and publish browser extensions for Chrome, Edge, Firefox, Safari, and every Chromium- or Gecko-based browser (Brave, Opera, Vivaldi, Yandex, Waterfox, Zen, Fl.

It is published on npm as @extension.dev/skill and hosted on GitHub at extensiondev/skill (234 weekly npm downloads, last repository push on 2026-10-20). Based on its public metadata, its operational scope includes: fetches arbitrary web urls.

Setup

These use the package this listing points to. Check the project’s own instructions before running anything.

npm command

npx -y @extension.dev/skill

Why this grade

DD — High risk signals

Signal-based grade (1/7 points): public source code. This reflects adoption and transparency, not a code review.

Popularity and upkeep

19/100
Weekly npm downloads
234
Listing last refreshed
2026-10-28

These are public popularity signals, not a maintenance check. Look at the repository’s commit history and open issues.

Security reports

No reports found for this package in our research (last checked 2026-10-29).

Check a specific version →

Risks to watch for

  • Untrusted web content & prompt injection: Fetches arbitrary web pages or remote endpoints where hidden instructions could manipulate agent behavior. Restrict outbound domains and review tool outputs.
  • Dependency & version pinning: Distributed via npm (@extension.dev/skill). Pin an exact release version or commit SHA rather than floating tags so upstream updates are reviewed first.

How to lower the risk

Least-privilege permissions

  • Give it access only to the specific folders, accounts or projects it needs, never your whole drive or admin account.
  • Use a separate, limited API key or login just for this tool so you can switch it off without affecting anything else.

Network isolation

  • Run it on a work computer or sandbox account, not one holding personal or company-sensitive data.
  • If your IT team can, limit which websites and services it is allowed to contact.

Monitoring

  • Check its activity history or logs weekly at first, and look at what it changed or sent.
  • Turn on alerts for new logins or unusual usage on any account it connects to.

Red flags to watch for

  • It asks for more access than its job requires, or prompts you to paste passwords.
  • It suddenly updates with new owners, or starts contacting unfamiliar websites.

Questions

How do I install @extension.dev/skill?

Install @extension.dev/skill with npm install @extension.dev/skill or run it directly with npx -y @extension.dev/skill. For agent integration and configuration flags, see the documentation at github.com/extensiondev/skill. Pin an exact version and pass --ignore-scripts if you want to block post-install hooks.

Are there security reports about @extension.dev/skill?

No reports found for this package in our research (last checked 2026-10-29). @extension.dev/skill currently holds Grade D (High risk signals) based on public adoption and transparency signals. Review the permissions and source repository before granting access to local files, shell commands, or API keys.

Is @extension.dev/skill actively maintained?

@extension.dev/skill has 234 weekly npm downloads, with its latest repository commit pushed on 2026-10-20. Our directory data was last refreshed on 2026-10-28. Check recent commit activity, release tags, and open issues at github.com/extensiondev/skill before pinning it in production.

What are alternatives to @extension.dev/skill?

You can compare @extension.dev/skill side by side with other Browser skills in the Related tools section on this page, or use the Compare tool on AgentArmorHQ.

README badge and team notes

Maintain or use @extension.dev/skill? Show its live grade in your GitHub README, docs site, or run a check from the terminal before you install.

AgentArmorHQ Risk Grade D for @extension.dev/skill

GitHub README Markdown:

markdown
[![AgentArmorHQ Risk Grade for @extension.dev/skill](https://agentarmorhq.com/api/badge/extensiondev-skill)](https://agentarmorhq.com/skills/extensiondev-skill)

HTML embed:

html
<a href="https://agentarmorhq.com/skills/extensiondev-skill"><img src="https://agentarmorhq.com/api/badge/extensiondev-skill" alt="AgentArmorHQ Risk Grade for @extension.dev/skill" height="20" /></a>

Terminal check:

terminal
curl -fsSL https://agentarmorhq.com/api/cli | node --input-type=module - check "extensiondev-skill"

Share with your security lead

Need sign-off to use @extension.dev/skill? Copy this note for Slack, a ticket or a pull request.

### AgentArmorHQ Security Review Memo: @extension.dev/skill
- **Listing URL:** https://agentarmorhq.com/skills/extensiondev-skill
- **Type:** AI agent skill
- **Risk Grade:** Grade D (High risk signals)
- **Outside Security Advisories on File:** 0

#### Permission & Blast-Radius Signals
- **Local files:** No local folder access noted
- **Command execution:** No shell command runner noted
- **Network reach:** Fetches arbitrary web URLs
- **Credentials:** No API token required
- **Package source:** npm (@extension.dev/skill)

#### Recommended Hardened Setup
- **Command:** `npx -y --ignore-scripts @extension.dev/skill`
- **Controls:** Pin an exact version in `.mcp.json`, scope access to a single workspace folder, and use a least-privilege read-only token where supported.

_Based on public adoption and transparency signals as of Oct 21, 2026. Our opinion, not a code audit or security guarantee._

Key facts

Type
AI agent skill
Publisher
extensiondev
Source code
github.com/extensiondev/skill
Install command
npm install @extension.dev/skill
Est. context load
~93 tokens idle · ~1.5k tokens when active (on-demand skill)
Popularity
234 weekly npm downloads
Last updated
2026-10-28
Last graded
2026-10-21

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