extension-analyze

extension-analyze is a skill for Claude Code, Codex from quangpl/browser-extension-skills. It costs 39 tokens per session (1,140 once invoked), scanned A, original, MIT.

A workflow for checking an existing Chrome extension for security, performance, best-practice, and Chrome Web Store compliance problems. It examines the extension's configuration, source code, message handling, storage, and dependencies.

In plain words
What is it for?
It helps inspect manifests, permissions, content-security settings, web-accessible resources, unsafe code patterns, possible cross-site scripting, and hardcoded secrets.
Why use it?
Manual review can miss unsafe code, excessive permissions, weak security settings, or publishing violations. The workflow organizes these checks into a repeatable audit.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit It helps inspect manifests, permissions, content-security settings, web-accessible resources, unsafe code patterns, possible cross-site scripting, and hardcoded secrets.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/quangpl/browser-extension-skills/extension-analyze
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 quangpl/browser-extension-skills --skill extension-analyze
Clone the repo
git clone --depth 1 https://github.com/quangpl/browser-extension-skills

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 extension-analyze

README.md
[![agentmods](https://agentmods.dev/badge/skills/quangpl/browser-extension-skills/extension-analyze/github.svg)](https://agentmods.dev/skills/quangpl/browser-extension-skills/extension-analyze)
Your own site
<a href="https://agentmods.dev/skills/quangpl/browser-extension-skills/extension-analyze"><img src="https://agentmods.dev/badge/skills/quangpl/browser-extension-skills/extension-analyze/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 extension-analyze

Your own site · 80×15
<a href="https://agentmods.dev/skills/quangpl/browser-extension-skills/extension-analyze"><img src="https://agentmods.dev/badge/skills/quangpl/browser-extension-skills/extension-analyze.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 39 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,140 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 original 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 $0.00039 $0.01140
Opus 5 $0.00019 $0.00570
Sonnet 5 $0.00008 $0.00228
Haiku 4.5 $0.00004 $0.00114

Measured 11d ago against content hash 2ffdb61fac3c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

extension-analyze 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 11d 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/extension-analyze/SKILL.md · 135 lines

How it starts

The opening of the file, as written. The whole thing — 135 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Extension Analyze (Security & Compliance Auditor)

Audit an existing Chrome extension. Do NOT just explain — execute the workflow.

Workflow (Execute This)

Step 1: Locate extension root and detect framework

Ask user for path if not provided. Detect framework:

ls wxt.config.ts plasmo.config.ts vite.config.ts manifest.json 2>/dev/null
  • Plasmo: manifest auto-generated; check package.json and plasmo.config.ts instead
  • WXT: check wxt.config.ts manifest section
  • Vanilla/CRXJS: check manifest.json directly

Step 2: Scan manifest.json (or equivalent config)

# Check MV version, permissions, host_permissions, CSP, web_accessible_resources
cat <ext>/manifest.json | jq '{manifest_version, permissions, host_permissions, content_security_policy, web_accessible_resources}'

Step 3: Quick grep scans

# XSS vectors
grep -rn "innerHTML\|outerHTML\|document\.write\|insertAdjacentHTML" <ext>/src --include="*.ts" --include="*.js"

# Unsafe patterns
grep -rn "eval(\|new Function(\|setTimeout.*string\|setInterval.*string" <ext>/src

# Hardcoded secrets
grep -rn "api_key\|apiKey\|secret\|password\|token" <ext>/src --include="*.ts" --include="*.js" | grep -v "\.test\." | grep -v "node_modules"

# HTTP (non-HTTPS) calls
grep -rn "http://" <ext>/src --include="*.ts" --include="*.js"

# Message handler sender validation
grep -rn "onMessage\|addListener" <ext>/src | grep -v "node_modules"

# Remote code loading
grep -rn "importScripts\|fetch.*\.js\|eval\|chrome\.scripting\.executeScript" <ext>/src

Step 4: Check CSP configuration

  • MV3 default CSP: script-src 'self'; object-src 'self'
  • Flag any unsafe-inline, unsafe-eval, or http: sources
  • Verify no remote script sources

Step 5: Dependency audit

cd <ext> && npm audit --json | jq '.vulnerabilities | to_entries[] | {pkg: .key, severity: .value.severity}'

Step 6: Generate report

Output findings grouped by severity. See Output Format below.

Read the full file on GitHub · 135 lines

Files

What ships with it

4 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.

  1. 11d ago First seen · 135 lines · 39 tokens per session scan A 2ffdb61fac3c

Subscribe to this mod's changes

extension-analyze is a skill published in the GitHub repository quangpl/browser-extension-skills (49 stars, last pushed 3mo ago), licensed MIT. It adds 39 tokens to every session and 1,140 once invoked, about $0.0002 per session on Opus 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.

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