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 skills add san-npm/skills-ws --skill nextjs-performancegit clone --depth 1 https://github.com/san-npm/skills-wsWrote 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/skills/san-npm/skills-ws/nextjs-performance)<a href="https://agentmods.dev/skills/san-npm/skills-ws/nextjs-performance"><img src="https://agentmods.dev/badge/skills/san-npm/skills-ws/nextjs-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/skills/san-npm/skills-ws/nextjs-performance"><img src="https://agentmods.dev/badge/skills/san-npm/skills-ws/nextjs-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 | $0.00089 | $0.00680 |
| Opus 5.5 | $0.00036 | $0.00272 |
| Sonnet 5.5 | $0.00018 | $0.00136 |
| Haiku 4.5 | $0.00009 | $0.00068 |
Grade A, and why
nextjs-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 2mo 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 — 33 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Next.js Performance
Real performance optimization for Next.js App Router. Not "add lazy loading" — actual diagnosis workflows, rendering-strategy decisions, and production caching patterns.
Version baseline (as of Jul 2026): Next.js 16.x is current (16.3 shipped Jun 29, 2026; docs track 16.2.x); examples target Next.js 15/16. Where 15 and 16 diverge (image priority→preload, minimumCacheTTL default, unstable_cache→'use cache', removed NextRequest.geo), both are called out. Verify versions/APIs at https://nextjs.org/docs and release notes at https://nextjs.org/blog. For SEO/metadata performance see the sibling seo-geo skill.
Reference guide
Read only the references needed for the current request:
- 1. Core Web Vitals — What Actually Causes Problems: references/1-core-web-vitals-what-actually-causes-problems.md
- 2. Rendering Strategy Decision Matrix: references/2-rendering-strategy-decision-matrix.md
- 3. Image Optimization: references/3-image-optimization.md
- 4. Bundle Analysis & Tree Shaking: references/4-bundle-analysis-tree-shaking.md
- 5. Edge Functions & Middleware: references/5-edge-functions-middleware.md
- 6. Font Loading: references/6-font-loading.md
- 7. Caching Strategies: references/7-caching-strategies.md
- 8. Performance Audit Workflow: references/8-performance-audit-workflow.md
- 9. Production Checklist: references/9-production-checklist.md
- Bundle: references/bundle.md
- Images: references/images.md
- Rendering: references/rendering.md
- Fonts: references/fonts.md
- Caching: references/caching.md
- Third-Party: references/third-party.md
- Monitoring: references/monitoring.md
What ships with it
17 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- agents/openai.yaml 170 B
- references/1-core-web-vitals-what-actually-causes-problems.md 4.2 KB
- references/2-rendering-strategy-decision-matrix.md 2.3 KB
- references/3-image-optimization.md 2.6 KB
- references/4-bundle-analysis-tree-shaking.md 1.6 KB
- references/5-edge-functions-middleware.md 2.4 KB
- references/6-font-loading.md 1.0 KB
- references/7-caching-strategies.md 3.3 KB
- references/8-performance-audit-workflow.md 5.4 KB
- references/9-production-checklist.md 40 B
- references/bundle.md 197 B
- references/caching.md 346 B
- references/fonts.md 151 B
- references/images.md 312 B
- references/monitoring.md 335 B
- references/rendering.md 162 B
- references/third-party.md 147 B
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.
- 2mo ago First seen · 33 lines · 89 tokens per session scan A 4e3b9c846b2c
nextjs-performance is a skill published in the GitHub repository san-npm/skills-ws (4 stars, last pushed 1mo ago), licensed MIT. It adds 89 tokens to every session and 680 once invoked, about $0.0004 per session on Opus 5.5. 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 2026-08-31.
nextjs-performance compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| nextjs-performancesan-npm/skills-ws | Skill | 4 | 1mo ago | MIT | A | 89 | Codex |
| build-ghost-appTryGhost/Ghost | Skill | 56k | yesterday | MIT | A | 44 | Claude Code, Codex |
| chakra-ui-builderchakra-ui/chakra-ui | Skill | 41k | yesterday | MIT | A | 214 | Claude Code, Codex |
| material-ui-tailwindmui/material-ui | Skill | 99k | yesterday | MIT | A | 67 | Claude Code, Codex |
| fuzzy-rankingTanStack/table | Skill | 29k | 4d ago | MIT | A | 62 | Claude Code, Codex |
| r3f-best-practiceszebbern/claude-code-guide | Skill | 4.7k | 3d ago | MIT | A | 74 | Claude Code, Codex |
| git-safetytamagui/tamagui | Skill | 14k | today | MIT | A | 0 | Claude Code |