node-core

node-core is a skill for Claude Code, Codex from adonai-labs/agent-runway. It costs 93 tokens per session (750 once invoked), scanned A, original, MIT.

A Node.js implementation guide for backend services, APIs, workers, and command-line tools. It covers architecture, asynchronous code, process shutdown, streams, security, monitoring, and production reliability.

In plain words
What is it for?
Use it when designing or reviewing Node.js servers, APIs, workers, queues, streams, and command-line programs.
Why use it?
It helps solve common Node.js problems such as unhandled promise failures, unsafe shutdowns, memory-heavy stream handling, and unreliable background work.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions Claude Code.

Good fit Use it when designing or reviewing Node.js servers, APIs, workers, queues, streams, and command-line programs.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/adonai-labs/agent-runway/skill-node-core
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 adonai-labs/agent-runway --skill skill-node-core
Clone the repo
git clone --depth 1 https://github.com/adonai-labs/agent-runway

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 node-core

README.md
[![agentmods](https://agentmods.dev/badge/skills/adonai-labs/agent-runway/skill-node-core.svg)](https://agentmods.dev/skills/adonai-labs/agent-runway/skill-node-core)
Your own site
<a href="https://agentmods.dev/skills/adonai-labs/agent-runway/skill-node-core"><img src="https://agentmods.dev/badge/skills/adonai-labs/agent-runway/skill-node-core.svg" alt="Measured on agentmods" height="20"></a>
Per session 93 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 750 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 $0.00093 $0.00750
Opus 5 $0.00046 $0.00375
Sonnet 5 $0.00019 $0.00150
Haiku 4.5 $0.00009 $0.00075

Measured 4d ago against content hash cdd6bb02431d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

node-core 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 4d 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.

src/stacks/node/skill-node-core/SKILL.md · 73 lines

How it starts

The opening of the file, as written. The whole thing — 73 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Node Core

How to invoke

After agent-runway add node, the skill is installed at .cursor/skills/node-core/. Use:

  • Cursor: @node-core or ask a Node.js question while editing *.js / *.ts (rules auto-attach)
  • Claude Code: reference .agent-runway/skills/node-core/SKILL.md or ask in context of Node.js files

Examples:

  • How should I structure this Express service?
  • How do I handle graceful shutdown with a Kafka consumer?
  • How do I test this worker with a real Redis instance?
  • How do I stream large files without loading them into memory?

Not sure which skill to use? Start with /start — it classifies intent and routes to the right skill.


Role

Act as a senior Node.js engineer with deep experience in production backend services, process lifecycle management, async patterns, stream processing, and operational reliability.

This skill is Node.js runtime-specific. For TypeScript type system guidance, combine with typescript-core. For system design and trade-offs, combine with architect.


Guiding principles

Simplicity first. Add complexity only when the problem demands it.

  • Start with the simplest structure that solves the problem
  • SOLID and DRY as guides, not ceremonies — SRP means one reason to change, not one file per concept
  • Clean Architecture at the right scale; a flat src/routes/, src/services/, src/db/ is fine for small services
  • No premature abstraction; extract only when duplication is in business logic, not glue code
  • Prefer explicit over clever; the next developer should understand the code without this skill

What this skill helps with

  • Project structure scaled to complexity
  • Async patterns: async/await, streams, graceful shutdown
  • Express / Fastify API patterns — middleware, routing, error handling
  • Testing: Supertest, Testcontainers, process and queue testing
  • Security: OWASP Node, child process safety, SSRF, secrets
  • Observability: Pino, OpenTelemetry, health checks

Skill files

Read the full file on GitHub · 73 lines

Files

What ships with it

6 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.

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. 4d ago First seen · 73 lines · 93 tokens per session scan A cdd6bb02431d

Subscribe to this mod's changes

node-core is a skill published in the GitHub repository adonai-labs/agent-runway (2 stars, last pushed 17d ago), licensed MIT. It adds 93 tokens to every session and 750 once invoked, about $0.0005 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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