xss-tester

xss-tester is an agent for coding agents from humaidhahm/opencode-pentester. It costs 54 tokens per session (818 once invoked), scanned A, original, no licence file.

A web-security agent for testing cross-site scripting, or XSS, where attacker-controlled text is made to run as code in a user’s browser. It checks reflected, stored, and DOM-based cases and captures browser evidence with Playwright.

In plain words
What is it for?
Use it for authorized XSS checks in React, Vue, or Angular applications, including testing injection points, web-filter bypasses, content-security-policy bypasses, and browser-visible proof.
Why use it?
It helps find XSS that may affect different web frameworks, evade web filters, or be limited by browser security policies.

Agent

Part of the pentest plugin — 1 skill, 12 agents shipped together

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.

agentmods
npx agentmods add agents/humaidhahm/opencode-pentester/xss-tester
Clone the repo
git clone --depth 1 https://github.com/humaidhahm/opencode-pentester

Or install pentest, the plugin that ships this one along with the rest of its 1 skill, 12 agents.

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 xss-tester

README.md
[![agentmods](https://agentmods.dev/badge/agents/humaidhahm/opencode-pentester/xss-tester.svg)](https://agentmods.dev/agents/humaidhahm/opencode-pentester/xss-tester)
Your own site
<a href="https://agentmods.dev/agents/humaidhahm/opencode-pentester/xss-tester"><img src="https://agentmods.dev/badge/agents/humaidhahm/opencode-pentester/xss-tester.svg" alt="Measured on agentmods" height="20"></a>
Per session 54 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 818 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
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.

ModelPer sessionOnce invoked
Fable 5 $0.00054 $0.00818
Opus 5 $0.00027 $0.00409
Sonnet 5 $0.00011 $0.00164
Haiku 4.5 $0.00005 $0.00082

Measured 4d ago against content hash 26e529838b2c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

xss-tester 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 4d 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.

curl -sI -H 'X-Forwarded-For: <script>alert(1)</script>' https://TARGET/
plugins/pentest/agents/xss-tester.md · 87 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

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. 4d ago First seen · 87 lines · 54 tokens per session scan A 26e529838b2c

Subscribe to this mod's changes

xss-tester is an agent published in the GitHub repository humaidhahm/opencode-pentester (23 stars, last pushed 8d ago), with no licence file. It adds 54 tokens to every session and 818 once invoked, about $0.0003 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.