Borrowing it
Nothing to install: this file belongs to davidruzicka/mcp4openapi. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/davidruzicka/mcp4openapi/main/.claude/skills/javascript-es2022/SKILL.mdgit clone --depth 1 https://github.com/davidruzicka/mcp4openapiWrote 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/davidruzicka/mcp4openapi/javascript-es2022)<a href="https://agentmods.dev/skills/davidruzicka/mcp4openapi/javascript-es2022"><img src="https://agentmods.dev/badge/skills/davidruzicka/mcp4openapi/javascript-es2022/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/davidruzicka/mcp4openapi/javascript-es2022"><img src="https://agentmods.dev/badge/skills/davidruzicka/mcp4openapi/javascript-es2022.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 | $0.00059 | $0.00387 |
| Opus 5.5 | $0.00024 | $0.00155 |
| Sonnet 5.5 | $0.00012 | $0.00077 |
| Haiku 4.5 | $0.00006 | $0.00039 |
Grade A, and why
javascript-es2022 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.
What it actually says
JavaScript ES2022
Coding standards
- Use JavaScript with ES2022 features and Node.js (20+) ESM modules.
- Use Node.js built-in modules and avoid external dependencies where possible.
- Ask the user if additional dependencies are required before adding them.
- Always use async/await for asynchronous code, and use
node:utilpromisifyto avoid callbacks. - Keep the code simple and maintainable.
- Use descriptive variable and function names.
- Do not add comments unless absolutely necessary; code should be self-explanatory.
- Never use
null; always useundefinedfor optional values. - Prefer functions over classes.
Naming and style
- Use PascalCase for classes, interfaces, enums, and type aliases; use camelCase for everything else.
- Exception: snake_case is permitted for DTOs, API contracts, and configuration files where external formats dictate it.
- Skip interface prefixes like
I; rely on descriptive names. - Name things for behavior or domain meaning, not implementation details.
Testing
- Use Vitest for testing.
- Write tests for all new features and bug fixes.
- Ensure tests cover edge cases and error handling.
- Never change production code to make it easier to test; test the real behavior.
Documentation
- When adding new features or making significant changes, update
README.mdwhere necessary.
User interactions
- Ask questions if implementation details or design choices are unclear.
- Always answer in the same language as the question, but keep generated code, comments, and docs in English.
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 · 37 lines · 59 tokens per session scan A f905136f7dbe
javascript-es2022 is a skill published in the GitHub repository davidruzicka/mcp4openapi (0 stars, last pushed 4d ago), licensed MIT. It adds 59 tokens to every session and 387 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 2026-08-31.
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