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/ivangrynenko/cursorrulesWrote 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/rules/ivangrynenko/cursorrules/javascript-performance)<a href="https://agentmods.dev/rules/ivangrynenko/cursorrules/javascript-performance"><img src="https://agentmods.dev/badge/rules/ivangrynenko/cursorrules/javascript-performance/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/rules/ivangrynenko/cursorrules/javascript-performance"><img src="https://agentmods.dev/badge/rules/ivangrynenko/cursorrules/javascript-performance.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 | $0.00198 | $0.00198 |
| Opus 5.5 | $0.00079 | $0.00079 |
| Sonnet 5.5 | $0.00040 | $0.00040 |
| Haiku 4.5 | $0.00020 | $0.00020 |
Grade A, and why
javascript-performance 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
1 near-identical copy found in the catalogue:
- javascript-performance — 100% identical, 0 lines differ
What it actually says
JavaScript Performance Optimization
actions:
-
type: enforce conditions:
-
pattern: "\buseState\(([^)]*)\)" message: "Avoid unnecessary state updates."
-
pattern: "React\.memo\(" message: "Consider using React.memo() to optimize component re-renders."
-
pattern: "\b\(\)\s*=>\s*{" message: "Avoid using anonymous functions in render methods."
-
-
type: suggest message: | Performance tips:
- Use memoization for expensive calculations.
- Optimize FlatList with performance props.
- Minimize unnecessary re-renders.
metadata: priority: high version: 1.0
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 · 34 lines · 198 tokens per session scan A 2055c06cc248
javascript-performance is a cursor rule published in the GitHub repository ivangrynenko/cursorrules (88 stars, last pushed 11mo ago), licensed MIT. It adds 198 tokens to every session, about $0.0008 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 2026-08-30.
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