Borrowing it
Nothing to install: this file belongs to FranRom/pupila. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/FranRom/pupila/main/.agents/skills/nodejs-best-practices/SKILL.mdgit clone --depth 1 https://github.com/FranRom/pupilaWrote 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/franrom/pupila/nodejs-best-practices)<a href="https://agentmods.dev/skills/franrom/pupila/nodejs-best-practices"><img src="https://agentmods.dev/badge/skills/franrom/pupila/nodejs-best-practices/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/franrom/pupila/nodejs-best-practices"><img src="https://agentmods.dev/badge/skills/franrom/pupila/nodejs-best-practices.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 | $0.00033 | $0.02038 |
| Opus 5.5 | $0.00013 | $0.00815 |
| Sonnet 5.5 | $0.00007 | $0.00408 |
| Haiku 4.5 | $0.00003 | $0.00204 |
Grade A, and why
nodejs-best-practices 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 1mo 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 — 338 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Node.js Best Practices
Principles + decision-making, Node.js 2025. THINK, don't memorize.
When to Use
Node.js architecture decisions, framework choice, async design, security, deployment.
How to Use
Teaches decision-making, not copy-paste code.
- ASK user prefs when unclear
- Pick framework/pattern by CONTEXT
- Don't default same solution every time
1. Framework Selection (2025)
Decision Tree
What are you building?
│
├── Edge/Serverless (Cloudflare, Vercel)
│ └── Hono (zero-dependency, ultra-fast cold starts)
│
├── High Performance API
│ └── Fastify (2-3x faster than Express)
│
├── Enterprise/Team familiarity
│ └── NestJS (structured, DI, decorators)
│
├── Legacy/Stable/Maximum ecosystem
│ └── Express (mature, most middleware)
│
└── Full-stack with frontend
└── Next.js API Routes or tRPC
Comparison Principles
| Factor | Hono | Fastify | Express |
|---|---|---|---|
| Best for | Edge, serverless | Performance | Legacy, learning |
| Cold start | Fastest | Fast | Moderate |
| Ecosystem | Growing | Good | Largest |
| TypeScript | Native | Excellent | Good |
| Learning curve | Low | Medium | Low |
Why these matter: Hono wins edge/serverless via zero deps + tiny runtime → fastest cold starts. Fastify wins perf via schema-based serialization → 2-3x Express throughput. Express wins on ecosystem maturity + middleware count. NestJS wins for teams needing DI/decorators/structure. Next.js/tRPC win when frontend colocated.
Selection Questions:
- Deployment target?
- Cold start critical?
- Team experience?
- Legacy code to maintain?
2. Runtime (2025)
Native TypeScript
Node.js 22+: --experimental-strip-types
├── Run .ts files directly
├── No build step needed for simple projects
└── Consider for: scripts, simple APIs
Module System
ESM (import/export)
├── Modern standard
├── Better tree-shaking
├── Async module loading
└── Use for: new projects
CommonJS (require)
├── Legacy compatibility
├── More npm packages support
└── Use for: existing codebases, some edge cases
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.
- 1mo ago First seen · 338 lines · 33 tokens per session scan A 9e24b6ef42d7
nodejs-best-practices is a skill published in the GitHub repository FranRom/pupila (36 stars, last pushed yesterday), licensed MIT. It adds 33 tokens to every session and 2,038 once invoked, about $0.0001 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 2026-08-30.
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