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/ratnesh-maurya/cursor-claude-personasWrote 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/ratnesh-maurya/cursor-claude-personas/rules-js-index-maps)<a href="https://agentmods.dev/rules/ratnesh-maurya/cursor-claude-personas/rules-js-index-maps"><img src="https://agentmods.dev/badge/rules/ratnesh-maurya/cursor-claude-personas/rules-js-index-maps/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/ratnesh-maurya/cursor-claude-personas/rules-js-index-maps"><img src="https://agentmods.dev/badge/rules/ratnesh-maurya/cursor-claude-personas/rules-js-index-maps.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 | $0.00000 | $0.00234 |
| Opus 5.5 | $0.00000 | $0.00094 |
| Sonnet 5.5 | $0.00000 | $0.00047 |
| Haiku 4.5 | $0.00000 | $0.00023 |
Grade A, and why
rules--js-index-maps 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
Build Index Maps for Repeated Lookups
Multiple .find() calls by the same key should use a Map.
Incorrect (O(n) per lookup):
function processOrders(orders: Order[], users: User[]) {
return orders.map(order => ({
...order,
user: users.find(u => u.id === order.userId)
}))
}
Correct (O(1) per lookup):
function processOrders(orders: Order[], users: User[]) {
const userById = new Map(users.map(u => [u.id, u]))
return orders.map(order => ({
...order,
user: userById.get(order.userId)
}))
}
Build map once (O(n)), then all lookups are O(1). For 1000 orders × 1000 users: 1M ops → 2K ops.
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 · 38 lines · 0 tokens per session scan A 5df1bdc2cfab
rules--js-index-maps is a cursor rule published in the GitHub repository ratnesh-maurya/cursor-claude-personas (12 stars, last pushed 7mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 234 tokens. 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.
Other cursor rules, from other repositories
cursor
You are working on the checkout service. Preserve transaction integrity and auditability.
orchestrator-main
Rules for the main orchestrator agent in multi-agent workflows.
lean
Answer densely. Cut filler, keep all technical signal.
react_hooks
React Hooks best practices for frontend package.
python
Python best practices with type hints, async patterns, and modern idioms.
general-python-project-rules
General Python project rules for all Python files in the project. Enforces specific Python versions and class usage.