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 pproenca/dot-skills --skill nextjs-bundle-optimizergit clone --depth 1 https://github.com/pproenca/dot-skillsWrote 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/pproenca/dot-skills/nextjs-bundle-optimizer)<a href="https://agentmods.dev/skills/pproenca/dot-skills/nextjs-bundle-optimizer"><img src="https://agentmods.dev/badge/skills/pproenca/dot-skills/nextjs-bundle-optimizer/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/pproenca/dot-skills/nextjs-bundle-optimizer"><img src="https://agentmods.dev/badge/skills/pproenca/dot-skills/nextjs-bundle-optimizer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00159 | $0.01504 |
| Opus 5 | $0.00079 | $0.00752 |
| Sonnet 5 | $0.00032 | $0.00301 |
| Haiku 4.5 | $0.00016 | $0.00150 |
Grade A, and why
nextjs-bundle-optimizer 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 6d 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 — 116 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Next.js Bundle & Build-Time Optimizer
Data-driven optimization loop for Next.js 16 applications. The skill orchestrates next experimental-analyze, builds, type checks, and tests to make verifiable improvements one change at a time.
When to Apply
Use this skill when:
- The user wants to reduce bundle size / First Load JS / route bundles in a Next.js 16 app.
- Production builds are slow and the user wants to diagnose and fix the bottleneck.
- The user shares analyzer output, a screenshot of the treemap, or asks "why is
<X>so big?" - A new dependency was added and bundles grew — they want to understand why and unwind it.
- The user wants to set a performance budget and enforce it iteratively.
Why iterative (not "apply all optimizations at once")
Bundle optimization is full of foot-guns. Examples:
- Moving a "client-only" dep behind
next/dynamiccan break SSR consumers that depended on its presence at first paint. experimental.optimizePackageImportswith the wrong package can mis-resolve subpath exports.- Aggressive
modularizeImportsregex rewrites can hit unintended modules. - Narrowing the polyfill target can break older mobile browsers in production.
The only reliable way is: one change, measure, verify, commit (or revert). This skill enforces that discipline through scripts.
Prerequisites
- Next.js 16+ project (the skill auto-detects from
package.json). git(the workflow uses commits as checkpoints and revert as rollback).jqavailable on PATH (used by analyze/compare scripts).- A clean working tree before starting (the verify step uses
git statusto confirm). - For projects still on Next.js 15 or earlier in webpack mode: the skill detects this and uses
@next/bundle-analyzerinstead ofexperimental-analyze. See gotchas.md.
Setup
On first use, run:
bash scripts/baseline.sh --setup
This walks through config.json interactively. If config.json already has values, scripts use those and skip the prompts.
What ships with it
12 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.
- config.json 1.1 KB
- gotchas.md 2.7 KB
- metadata.json 1.0 KB
- references/optimizations.md 13 KB
- references/workflow.md 9.5 KB
- scripts/_common.sh 2.2 KB runs code
- scripts/analyze.sh 5.7 KB runs code
- scripts/baseline.sh 4.6 KB runs code
- scripts/compare.sh 3.3 KB runs code
- scripts/diagnose.sh 4.7 KB runs code
- scripts/measure.sh 1.9 KB runs code
- scripts/verify.sh 2.4 KB runs code
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.
- 6d ago First seen · 116 lines · 159 tokens per session scan A f3c6cb0f7507
nextjs-bundle-optimizer is a skill published in the GitHub repository pproenca/dot-skills (205 stars, last pushed 24d ago), licensed MIT. It adds 159 tokens to every session and 1,504 once invoked, about $0.0008 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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