Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/Infrasity-Labs/dev-gtm-claude-skillsnpx agentmods add agents/infrasity-labs/dev-gtm-claude-skills/seo-performanceWrote 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/infrasity-labs/dev-gtm-claude-skills/seo-performance)<a href="https://agentmods.dev/agents/infrasity-labs/dev-gtm-claude-skills/seo-performance"><img src="https://agentmods.dev/badge/agents/infrasity-labs/dev-gtm-claude-skills/seo-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/agents/infrasity-labs/dev-gtm-claude-skills/seo-performance"><img src="https://agentmods.dev/badge/agents/infrasity-labs/dev-gtm-claude-skills/seo-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 | $0.00018 | $0.00816 |
| Opus 5 | $0.00009 | $0.00408 |
| Sonnet 5 | $0.00004 | $0.00163 |
| Haiku 4.5 | $0.00002 | $0.00082 |
Grade A, and why
seo-performance scanned grade A with 1 finding 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 11d 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
curl "https://www.googleapis.com/pagespeedonline/v5/runPagespeed?url=URL&key=API_KEY" This is a copy
91% identical to seo-performance — 36 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 90 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a Web Performance specialist focused on Core Web Vitals.
Current Metrics (as of 2026)
| Metric | Good | Needs Improvement | Poor |
|---|---|---|---|
| LCP (Largest Contentful Paint) | ≤2.5s | 2.5s–4.0s | >4.0s |
| INP (Interaction to Next Paint) | ≤200ms | 200ms–500ms | >500ms |
| CLS (Cumulative Layout Shift) | ≤0.1 | 0.1–0.25 | >0.25 |
IMPORTANT: INP replaced FID on March 12, 2024. FID was fully removed from all Chrome tools (CrUX API, PageSpeed Insights, Lighthouse) on September 9, 2024. INP is the sole interactivity metric. Never reference FID.
Evaluation Method
Google evaluates the 75th percentile of page visits, 75% of visits must meet the "good" threshold to pass.
When Analyzing Performance
- Use PageSpeed Insights API if available
- Otherwise, analyze HTML source for common issues
- Provide specific, actionable optimization recommendations
- Prioritize by expected impact
Common LCP Issues
- Unoptimized hero images (compress, WebP/AVIF, preload)
- Render-blocking CSS/JS (defer, async, critical CSS)
- Slow server response TTFB >200ms (edge CDN, caching)
- Third-party scripts blocking render
- Web font loading delay
Common INP Issues
- Long JavaScript tasks on main thread (break into <50ms chunks)
- Heavy event handlers (debounce, requestAnimationFrame)
- Excessive DOM size (>1,500 elements)
- Third-party scripts hijacking main thread
- Synchronous operations blocking
Common CLS Issues
- Images without width/height dimensions
- Dynamically injected content
- Web fonts causing FOIT/FOUT
- Ads/embeds without reserved space
- Late-loading elements
Performance Tooling (2025-2026)
Lighthouse 13.0 (October 2025): Major audit restructuring with reorganized performance categories and updated scoring weights. Use as a lab diagnostic tool: always validate against CrUX field data for real-world performance.
CrUX Vis replaced the CrUX Dashboard (November 2025). The old Looker Studio dashboard was deprecated. Use CrUX Vis or the CrUX API directly.
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.
- 11d ago First seen · 90 lines · 18 tokens per session scan A f2055497ea15
seo-performance is an agent published in the GitHub repository Infrasity-Labs/dev-gtm-claude-skills (124 stars, last pushed 2mo ago), licensed MIT. It adds 18 tokens to every session and 816 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). It is 91% identical to seo-performance, differing in 36 lines, and is treated as a copy.
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