js-secrets-extraction

js-secrets-extraction is a skill for Claude Code, Codex from uphiago/recon-skills. It costs 26 tokens per session (3,235 once invoked), scanned A, original, MIT.

An analysis process for downloaded JavaScript files and source maps, which can show how a web application was built, to look for exposed keys, tokens, URLs, and routes.

In plain words
What is it for?
Reviewing JavaScript applications, especially those using React, Angular, Vue, Firebase, Supabase, or Auth0, for embedded secrets and internal endpoints.
Why use it?
Browser code is sent to visitors and may accidentally contain configuration or access details that should have stayed private.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: positional $N argument.

Good fit Reviewing JavaScript applications, especially those using React, Angular, Vue, Firebase, Supabase, or Auth0, for embedded secrets and internal endpoints.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/uphiago/recon-skills/js-secrets-extraction
About the project

Recon Skills is a pack of security-testing skills covering reconnaissance, web applications, APIs, authentication, vulnerability validation, cloud infrastructure, and reporting. Security professionals use it for authorized assessments of systems they own or have written permission to test. The catalogue entries are individual skills from the pack.

uphiago/recon-skills · 1,247 stars · on GitHub · hiago.sh

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 uphiago/recon-skills --skill js-secrets-extraction
Clone the repo
git clone --depth 1 https://github.com/uphiago/recon-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 js-secrets-extraction

README.md
[![agentmods](https://agentmods.dev/badge/skills/uphiago/recon-skills/js-secrets-extraction/github.svg)](https://agentmods.dev/skills/uphiago/recon-skills/js-secrets-extraction)
Your own site
<a href="https://agentmods.dev/skills/uphiago/recon-skills/js-secrets-extraction"><img src="https://agentmods.dev/badge/skills/uphiago/recon-skills/js-secrets-extraction/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 js-secrets-extraction

Your own site · 80×15
<a href="https://agentmods.dev/skills/uphiago/recon-skills/js-secrets-extraction"><img src="https://agentmods.dev/badge/skills/uphiago/recon-skills/js-secrets-extraction.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 26 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,235 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00026 $0.03235
Opus 5 $0.00013 $0.01618
Sonnet 5 $0.00005 $0.00647
Haiku 4.5 $0.00003 $0.00324

Measured 9d ago against content hash 48c36ca6b166, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

js-secrets-extraction 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/scan_js.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 --max-time 30 --connect-timeout 10 -s "https://target.com" > index.html
recon/js-secrets-extraction/SKILL.md · 281 lines

How it starts

The opening of the file, as written. The whole thing — 281 lines — stays where its author put it; the contents beside it link to each section on GitHub.

JS Bundle & Source Map Analysis -- Secret Extraction

When to Use

  • ALWAYS after initial web enumeration
  • When you find modern SPA (React, Angular, Vue)
  • When target uses Firebase, Supabase, Auth0
  • Higher yield than directory scanning on many targets

Why Analyze JS Bundles

Modern JavaScript bundles (Webpack, Vite, esbuild) often contain:

  • Hardcoded API keys and tokens
  • Internal API URLs
  • Firebase, Auth0, Supabase configurations
  • Environment variables (VITE_, REACT_APP_, NEXT_PUBLIC_*)
  • Internal routes

Bundle Download and Analysis

curl --max-time 30 --connect-timeout 10 -s "https://target.com" > index.html
grep -Eo 'src="[^"]*\.js"' index.html | cut -d'"' -f2 | while read js; do
  curl --max-time 30 --connect-timeout 10 -s "https://target.com$js" > "$(basename $js)"
done

# Search for secrets in bundles
grep -rEn "(apiKey|api_key|API_KEY|token|secret|password|clientId|client_id|auth0|firebase|supabase)[\"'\"]?[[:space:]]*[:=][[:space:]]*[\"'\'][^\"'\']{8,}" *.js

Source Map Reconstruction

curl --max-time 30 --connect-timeout 10 -sI "https://target.com/assets/index-abc123.js.map"
curl --max-time 30 --connect-timeout 10 -sI "https://target.com/static/js/main.12345.js.map"

# If HTTP 200, use for reconstruction:
# https://unminify.com
# https://source-map-visualization.netlify.app

Real-world case: Enterprise Angular SPA admin, 2 JS bundles (250KB each) exposed:

  • Internal API URL (apiv3.empresa.com.br)
  • Firebase API key (AIzaSy...2GXA)
  • Encryption keys (AD5oDjsJaTJOzLe1Llj9mz)
  • Cloudinary upload endpoint

Port-Specific URL Analysis

Modern deployments often serve the main SPA on port 443 and admin/API on separate ports (8080, 8081, 8084). Always check JS bundles on ALL discovered ports:

# Check source maps on every open port
for port in 443 8080 8081 8084; do
  curl --max-time 30 --connect-timeout 10 -sI "https://target.com:$port/static/js/main.*.js.map" 2>/dev/null
  curl --max-time 30 --connect-timeout 10 -sI "https://target.com:$port/assets/index-*.js.map" 2>/dev/null
done

Read the full file on GitHub · 281 lines

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 · 281 lines · 26 tokens per session scan A 48c36ca6b166

Subscribe to this mod's changes

js-secrets-extraction is a skill published in the GitHub repository uphiago/recon-skills (1,247 stars, last pushed 7d ago), licensed MIT. It adds 26 tokens to every session and 3,235 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.

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