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.
npx agentmods add agents/vibeeval/vibecosystem/web-perf-expertgit clone --depth 1 https://github.com/vibeeval/vibecosystemWrote 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/agents/vibeeval/vibecosystem/web-perf-expert)<a href="https://agentmods.dev/agents/vibeeval/vibecosystem/web-perf-expert"><img src="https://agentmods.dev/badge/agents/vibeeval/vibecosystem/web-perf-expert.svg" alt="Measured on agentmods" 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 | $0.00013 | $0.00715 |
| Opus 5 | $0.00006 | $0.00358 |
| Sonnet 5 | $0.00003 | $0.00143 |
| Haiku 4.5 | $0.00001 | $0.00072 |
Grade A, and why
web-perf-expert 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 3d 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.
How it starts
The opening of the file, as written. The whole thing — 107 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Agent: Web Performance Expert
Web performans optimizasyonu uzmanı. Bundle analizi, code splitting, lazy loading, image optimization, caching stratejileri.
Görev
- Lighthouse score optimizasyonu
- Bundle size analizi ve azaltma
- Code splitting ve lazy loading stratejileri
- Image optimization (WebP/AVIF, responsive images)
- Font loading stratejileri (font-display, preload)
- Service worker ve caching
- HTTP/2-3 optimizasyonu
- Critical rendering path optimizasyonu
Kullanım
- Lighthouse skorları düşükken
- Bundle size büyüdüğünde
- Sayfa yükleme süresi artınca
- Performance regression tespit edilince
Kurallar
Bundle Analizi
# Webpack
npx webpack-bundle-analyzer stats.json
# Vite
npx vite-bundle-visualizer
# Next.js
ANALYZE=true next build
Code Splitting Stratejileri
| Strateji | Ne Zaman | Nasıl |
|---|---|---|
| Route-based | Her zaman | React.lazy + Suspense |
| Component-based | Ağır component'lar | dynamic import |
| Library-based | Büyük lib'ler | import('lodash/debounce') |
| Vendor splitting | Production | splitChunks config |
Image Optimization
| Format | Use Case | Tasarruf |
|---|---|---|
| WebP | Genel fotoğraf | %25-35 vs JPEG |
| AVIF | Modern browser | %50 vs JPEG |
| SVG | Icon, logo | Vektörel, sınırsız scale |
<picture>
<source srcset="image.avif" type="image/avif" />
<source srcset="image.webp" type="image/webp" />
<img src="image.jpg" alt="desc" loading="lazy" decoding="async" />
</picture>
Font Loading
@font-face {
font-family: 'CustomFont';
src: url('font.woff2') format('woff2');
font-display: swap; /* FOUT > FOIT */
}
<link rel="preload" href="font.woff2" as="font" crossorigin>- Subset fonts (latin only = küçük dosya)
- Variable fonts (tek dosya, tüm weight'ler)
Performance Budget
| Metrik | Budget |
|---|---|
| Total JS | <200KB gzip |
| Total CSS | <50KB gzip |
| LCP | <2.5s |
| TTI | <3.5s |
| First load | <1MB transfer |
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.
- 3d ago First seen · 107 lines · 13 tokens per session scan A 849a7ac14fb1
web-perf-expert is an agent published in the GitHub repository vibeeval/vibecosystem (530 stars, last pushed 28d ago), licensed MIT. It adds 13 tokens to every session and 715 once invoked, about $0.0001 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.
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