js-backend-expert

js-backend-expert is a skill for Claude Code, Codex from roedyrustam/vibes-plug. It costs 77 tokens per session (3,067 once invoked), scanned A, original, MIT.

A practical guide to building JavaScript and TypeScript backend services with Node.js, Bun, or Deno. It covers web servers, APIs, databases, background jobs, WebSockets, and microservices.

In plain words
What is it for?
Use it when creating or refactoring REST, GraphQL, WebSocket, or serverless backends, connecting databases, processing background jobs, or deploying to edge platforms.
Why use it?
It helps you choose suitable backend tools and avoid common design and performance problems when building server-side applications.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it when creating or refactoring REST, GraphQL, WebSocket, or serverless backends, connecting databases, processing background jobs, or deploying to edge platforms.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/roedyrustam/vibes-plug/js-backend-expert
Install

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.

Any agent
npx skills add roedyrustam/vibes-plug --skill js-backend-expert
Clone the repo
git clone --depth 1 https://github.com/roedyrustam/vibes-plug

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for js-backend-expert

README.md
[![agentmods](https://agentmods.dev/badge/skills/roedyrustam/vibes-plug/js-backend-expert/github.svg)](https://agentmods.dev/skills/roedyrustam/vibes-plug/js-backend-expert)
Your own site
<a href="https://agentmods.dev/skills/roedyrustam/vibes-plug/js-backend-expert"><img src="https://agentmods.dev/badge/skills/roedyrustam/vibes-plug/js-backend-expert/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.

agentmods 80×15 button for js-backend-expert

Your own site · 80×15
<a href="https://agentmods.dev/skills/roedyrustam/vibes-plug/js-backend-expert"><img src="https://agentmods.dev/badge/skills/roedyrustam/vibes-plug/js-backend-expert.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 77 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,067 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00077 $0.03067
Opus 5 $0.00039 $0.01533
Sonnet 5 $0.00015 $0.00613
Haiku 4.5 $0.00008 $0.00307

Measured 5d ago against content hash c87e2c1dae4c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

js-backend-expert 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 5d 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.

async fetch(request: Request, env: Env): Promise<Response> {
skills/js-backend-expert/SKILL.md · 220 lines

How it starts

The opening of the file, as written. The whole thing — 220 lines — stays where its author put it; the contents beside it link to each section on GitHub.

JS Backend Expert (Node.js 24 LTS / Bun 1.2 / Deno 2.x Edition)

English | Bahasa Indonesia


English

Description

Production-grade guidance for building fast, scalable, and resilient JavaScript/TypeScript backend APIs, microservices, and serverless functions across Node.js 24 (LTS), Bun 1.2+, and Deno 2.x. Covers high-throughput frameworks (Fastify 5, Hono, Express 5, NestJS), type-safe ORMs (Drizzle, Prisma 6), Hono RPC for type-safe full-stack communication, Edge Runtime patterns, WebSockets, BullMQ background jobs, and graceful shutdown handling.

Trigger Conditions

  • Bootstrapping or refactoring a Node.js, Bun, or Deno backend application or microservice.
  • Writing RESTful, GraphQL, WebSocket, or SSE (Server-Sent Events) API endpoints.
  • Developing web servers using Fastify 5, Hono, Express 5, or NestJS.
  • Building type-safe full-stack apps with Hono RPC or tRPC.
  • Deploying backend logic to Edge Runtimes (Cloudflare Workers, Vercel Edge).
  • Interacting with databases using Drizzle ORM, Prisma 6, or Kysely.
  • Setting up background job processing with BullMQ and Redis.
  • Implementing rate limiting, CORS, Content Security Policy (CSP), and JWT/Session authentication.
  • Writing backend tests using Vitest, Supertest, or Node's native node:test runner.

Runtime Matrix (Node.js 24 vs Bun 1.2 vs Deno 2.x)

Feature / Runtime Node.js 24 (LTS) Bun 1.2+ Deno 2.x
Module Standard Native ESM / CJS Native ESM / CJS Native ESM
.env Loading Native --env-file Native Native
TypeScript Execution Native --experimental-strip-types / tsx Native (Zero-config) Native (Zero-config)
HTTP Server node:http / Fastify Bun.serve() / Hono Deno.serve() / Hono
Native WebSockets Built-in (WebSocket) Built-in (Bun.serve) Built-in (Deno.upgradeWebSocket)
Package Manager npm / pnpm bun (built-in) npm / jsr
Test Runner node:test / Vitest bun test deno test
Edge Deploy Vercel Serverless Railway / Fly.io Deno Deploy

Read the full file on GitHub · 220 lines

Changes

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.

  1. 5d ago First seen · 220 lines · 77 tokens per session scan A c87e2c1dae4c

Subscribe to this mod's changes

js-backend-expert is a skill published in the GitHub repository roedyrustam/vibes-plug (50 stars, last pushed yesterday), licensed MIT. It adds 77 tokens to every session and 3,067 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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