web-frontend-performance

web-frontend-performance is a cursor rule for Cursor from djm204/frankenbeast. It costs 2 tokens per session (478 once invoked), scanned A, original, no licence file.

Guidelines for building fast, responsive web applications that react quickly to user actions.

In plain words
What is it for?
Use them when improving page speed, responsiveness, and the amount of work a browser must do.
Why use it?
They help identify and avoid frontend choices that make pages slow or difficult to use.

Cursor rule for Cursor

Written for Cursor: installed under .cursor/.

Good fit Use them when improving page speed, responsiveness, and the amount of work a browser must do.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/djm204/frankenbeast/web-frontend-performance
Install

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.

Clone the repo
git clone --depth 1 https://github.com/djm204/frankenbeast

Made for: Cursor.

Wrote 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.

agentmods badge for web-frontend-performance

README.md
[![agentmods](https://agentmods.dev/badge/rules/djm204/frankenbeast/web-frontend-performance.svg)](https://agentmods.dev/rules/djm204/frankenbeast/web-frontend-performance)
Your own site
<a href="https://agentmods.dev/rules/djm204/frankenbeast/web-frontend-performance"><img src="https://agentmods.dev/badge/rules/djm204/frankenbeast/web-frontend-performance.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.

agentmods 80×15 button for web-frontend-performance

Your own site · 80×15
<a href="https://agentmods.dev/rules/djm204/frankenbeast/web-frontend-performance"><img src="https://agentmods.dev/badge/rules/djm204/frankenbeast/web-frontend-performance.svg?style=web" alt="Reviewed on agentmods" width="80" height="15"></a>
Per session 2 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 478 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00002 $0.00478
Opus 5 $0.00001 $0.00239
Sonnet 5 $0.00000 $0.00096
Haiku 4.5 $0.00000 $0.00048

Measured 5d ago against content hash fd31e6f3a029, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

web-frontend-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 5d 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.

.cursor/rules/web-frontend-performance.mdc · 74 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

Changes

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.

  1. 5d ago First seen · 74 lines · 2 tokens per session scan A fd31e6f3a029

Subscribe to this mod's changes

web-frontend-performance is a cursor rule published in the GitHub repository djm204/frankenbeast (2 stars, last pushed 5d ago), with no licence file. It adds 2 tokens to every session and 478 once invoked, about $0.0000 per session on Opus 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.