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.
npx skills add jd-opensource/JoySafeter --skill pentest-client-advancedgit clone --depth 1 https://github.com/jd-opensource/JoySafeterWrote 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.
[](https://agentmods.dev/skills/jd-opensource/joysafeter/pentest-client-advanced)<a href="https://agentmods.dev/skills/jd-opensource/joysafeter/pentest-client-advanced"><img src="https://agentmods.dev/badge/skills/jd-opensource/joysafeter/pentest-client-advanced/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.
<a href="https://agentmods.dev/skills/jd-opensource/joysafeter/pentest-client-advanced"><img src="https://agentmods.dev/badge/skills/jd-opensource/joysafeter/pentest-client-advanced.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00036 | $0.00739 |
| Opus 5.5 | $0.00014 | $0.00296 |
| Sonnet 5.5 | $0.00007 | $0.00148 |
| Haiku 4.5 | $0.00004 | $0.00074 |
Grade A, and why
pentest-client-advanced 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 1mo 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.
| CORS Testing | CORScanner, curl, custom PoC pages | CORS misconfiguration detection | How it starts
The opening of the file, as written. The whole thing — 58 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Pentest Client Advanced
Purpose
Test advanced client-side attack surfaces beyond XSS. Six WSTG-CLNT items remain unchecked in Shannon's pipeline — these are distinct attack classes requiring different methodology than taint analysis.
Prerequisites
Authorization Requirements
- Written authorization with client-side testing scope
- Test domains for hosting PoC HTML pages (attacker-controlled origin)
- Browser testing environment with DevTools access
- Target user simulation — ability to test cross-origin interactions
Environment Setup
- Modern browser with DevTools (Chrome/Firefox)
- Burp Suite for intercepting WebSocket and cross-origin traffic
- Local HTTP server for hosting PoC pages (python -m http.server)
- Playwright for automated browser-based attack verification
Core Workflow
- CORS Misconfiguration: Test reflected Origin in ACAO header, null origin bypass, subdomain wildcard abuse, credential leakage via cross-origin requests (WSTG-CLNT-07).
- WebSocket Security: Missing auth on WS upgrade, CSWSH (Cross-Site WebSocket Hijacking), injection through WS messages, missing origin validation (WSTG-CLNT-10).
- Clickjacking: Missing X-Frame-Options / CSP frame-ancestors, UI redressing, drag-and-drop hijacking, multi-step clickjacking chains (WSTG-CLNT-09).
- postMessage Abuse: Missing origin validation in message handlers, DOM manipulation via cross-origin messages, prototype pollution through postMessage (WSTG-CLNT-11).
- CSS Injection: Data exfiltration via CSS attribute selectors + background-image, CSS-based keylogging, style injection for UI manipulation (WSTG-CLNT-05).
- Client-Side Storage: Sensitive data in localStorage/sessionStorage, IndexedDB exposure, service worker cache poisoning (WSTG-CLNT-06).
- PoC Construction: Build HTML pages demonstrating each attack with real impact.
WSTG Coverage
| WSTG ID | Test Name | Status |
|---|---|---|
| WSTG-CLNT-05 | CSS Injection | ✅ |
| WSTG-CLNT-06 | Client-Side Resource Manipulation | ✅ |
| WSTG-CLNT-07 | Cross-Origin Resource Sharing | ✅ |
| WSTG-CLNT-09 | Clickjacking | ✅ |
| WSTG-CLNT-10 | WebSocket Testing | ✅ |
| WSTG-CLNT-11 | Web Messaging | ✅ |
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.
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.
- 1mo ago First seen · 58 lines · 36 tokens per session scan A b18f497e6583
pentest-client-advanced is a skill published in the GitHub repository jd-opensource/JoySafeter (315 stars, last pushed 3d ago), licensed Apache-2.0. It adds 36 tokens to every session and 739 once invoked, about $0.0001 per session on Opus 5.5. 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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