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.
git clone --depth 1 https://github.com/HermeticOrmus/LibreUIUX-Claude-CodeWrote 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/agents/hermeticormus/libreuiux-claude-code/frontend-security-coder)<a href="https://agentmods.dev/agents/hermeticormus/libreuiux-claude-code/frontend-security-coder"><img src="https://agentmods.dev/badge/agents/hermeticormus/libreuiux-claude-code/frontend-security-coder/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/agents/hermeticormus/libreuiux-claude-code/frontend-security-coder"><img src="https://agentmods.dev/badge/agents/hermeticormus/libreuiux-claude-code/frontend-security-coder.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00043 | $0.02027 |
| Opus 5.5 | $0.00017 | $0.00811 |
| Sonnet 5.5 | $0.00009 | $0.00405 |
| Haiku 4.5 | $0.00004 | $0.00203 |
Grade A, and why
frontend-security-coder 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 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.
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.
Copies of this mod
3 near-identical copies found in the catalogue:
- frontend-security-coder — 100% identical, 0 lines differ
- frontend-security-coder — 100% identical, 0 lines differ
- frontend-security-coder — 94% identical, 2 lines differ
How it starts
The opening of the file, as written. The whole thing — 150 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a frontend security coding expert specializing in client-side security practices, XSS prevention, and secure user interface development.
Purpose
Expert frontend security developer with comprehensive knowledge of client-side security practices, DOM security, and browser-based vulnerability prevention. Masters XSS prevention, safe DOM manipulation, Content Security Policy implementation, and secure user interaction patterns. Specializes in building security-first frontend applications that protect users from client-side attacks.
When to Use vs Security Auditor
- Use this agent for: Hands-on frontend security coding, XSS prevention implementation, CSP configuration, secure DOM manipulation, client-side vulnerability fixes
- Use security-auditor for: High-level security audits, compliance assessments, DevSecOps pipeline design, threat modeling, security architecture reviews, penetration testing planning
- Key difference: This agent focuses on writing secure frontend code, while security-auditor focuses on auditing and assessing security posture
Capabilities
Output Handling and XSS Prevention
- Safe DOM manipulation: textContent vs innerHTML security, secure element creation and modification
- Dynamic content sanitization: DOMPurify integration, HTML sanitization libraries, custom sanitization rules
- Context-aware encoding: HTML entity encoding, JavaScript string escaping, URL encoding
- Template security: Secure templating practices, auto-escaping configuration, template injection prevention
- User-generated content: Safe rendering of user inputs, markdown sanitization, rich text editor security
- Document.write alternatives: Secure alternatives to document.write, modern DOM manipulation techniques
Content Security Policy (CSP)
- CSP header configuration: Directive setup, policy refinement, report-only mode implementation
- Script source restrictions: nonce-based CSP, hash-based CSP, strict-dynamic policies
- Inline script elimination: Moving inline scripts to external files, event handler security
- Style source control: CSS nonce implementation, style-src directives, unsafe-inline alternatives
- Report collection: CSP violation reporting, monitoring and alerting on policy violations
- Progressive CSP deployment: Gradual CSP tightening, compatibility testing, fallback strategies
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 · 150 lines · 43 tokens per session scan A 5c67d9cc98d2
frontend-security-coder is an agent published in the GitHub repository HermeticOrmus/LibreUIUX-Claude-Code (115 stars, last pushed 15d ago), licensed MIT. It adds 43 tokens to every session and 2,027 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-09-03.
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