performance

A set of rules for navigation, caching, and progressive web app behavior. A progressive web app is a website designed to behave more like an installable app.

In plain words
What is it for?
Implementing navigation and mutation refreshes, configuring prefetching, protecting authenticated routes, and limiting offline or cached content to safe static files.
Why use it?
It helps prevent full-page reloads, stale customer data, missing loading screens, and unsafe caching of private information.

Cursor rule for Cursor

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.

agentmods
npx agentmods add rules/krivoox/agent-stack-template/performance
Clone the repo
git clone --depth 1 https://github.com/krivoox/agent-stack-template

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 346 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original 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 $0.00000 $0.00346
Opus 5 $0.00000 $0.00173
Sonnet 5 $0.00000 $0.00069
Haiku 4.5 $0.00000 $0.00035

Measured yesterday against content hash 48aae35adb95, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

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 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.

.cursor/rules/performance.mdc · 34 lines

What it actually says

Performance and navigation

Detail: docs/architecture.md §7.

Required

  1. Soft navigation only. The shell in (app)/layout.tsx is persistent; a full page reload during an authenticated session is a bug.
  2. Every (app) segment ships a loading.tsx built on PageSkeleton.
  3. experimental.staleTimes.dynamic: 0. Perceived speed comes from skeletons and prefetch, not from showing data captured before the last mutation.
  4. Nav destinations live in nav-config.ts so idle prefetch covers them.
  5. After a mutation, use refreshAfterMutation / navigateAndRefresh from src/lib/navigation.ts. A plain router.push can land on a Client Router Cache entry captured before the write.
  6. Authenticated routes are private, no-store — add the prefix to PRIVATE_ROUTE_PREFIXES in next.config.ts.

Forbidden

  • Cross-request caching of tenant data (balances, membership, anything per-user).
  • A service worker that caches HTML or /api/*. Static assets under /_next/static/* only — they are content-hashed and immutable.
  • Offline UI that displays stale authoritative data. Users trust what they see; a stale number is worse than no number.
  • Relaxing staleTimes.dynamic to make a page feel faster.
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. yesterday First seen · 34 lines · 0 tokens per session scan A 48aae35adb95

Subscribe to this mod's changes

performance is a cursor rule published in the GitHub repository krivoox/agent-stack-template (30 stars, last pushed 11d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 346 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 2026-08-30.