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 agentmods add agents/hermeticormus/claude-code-game-development/frontend-security-codergit clone --depth 1 https://github.com/HermeticOrmus/claude-code-game-developmentWrote 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/claude-code-game-development/frontend-security-coder)<a href="https://agentmods.dev/agents/hermeticormus/claude-code-game-development/frontend-security-coder"><img src="https://agentmods.dev/badge/agents/hermeticormus/claude-code-game-development/frontend-security-coder.svg" alt="Measured on agentmods" 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 | $0.00043 | $0.02027 |
| Opus 5 | $0.00022 | $0.01014 |
| Sonnet 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 yesterday.
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.
This is a copy
100% identical to frontend-security-coder — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
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.
- yesterday First seen · 150 lines · 43 tokens per session scan A 5c67d9cc98d2
frontend-security-coder is an agent published in the GitHub repository HermeticOrmus/claude-code-game-development (59 stars, last pushed 3mo ago), licensed MIT. It adds 43 tokens to every session and 2,027 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to frontend-security-coder, differing in 0 lines, and is treated as a copy.
Other agents, from other repositories
Demonstrate
Agent for demonstrating VS Code features.
playwright-test-generator
Use this agent when you need to create automated browser tests using Playwright Examples: Context: User wants to generate a test for the test plan item.
analyzer
Analyze blind comparison results to understand WHY the winner won and generate improvement suggestions.
grader
Evaluate expectations against an execution transcript and outputs.
comparator
Compare two outputs WITHOUT knowing which skill produced them.
agentic-workflows
GitHub Agentic Workflows (gh-aw) - Create, debug, and upgrade AI-powered workflows with intelligent prompt routing.