Node Skill

Skill ID: node
Version: 2.0
Updated: 2026-07-16

Purpose

Activate this skill when A Node.js service, stream, worker, package, or event-loop behavior changes.

Why

An API or worker contract, bounded concurrency design, lifecycle handling, diagnostics, and Node-version test evidence is the minimum reviewable deliverable for this domain. A generic "inspect, change, test" loop omits the domain decisions and failure evidence needed for production use.

Trigger Conditions

A Node.js service, stream, worker, package, or event-loop behavior changes.
The requester expects an implementation, design, audit, or release decision in this domain.

Required Inputs

The exact target and acceptance criteria.
Repository-pinned versions, environment constraints, and available evidence.
Data classification, effect permissions, and owner where the procedure can affect external systems.

Produced Artifacts

An API or worker contract
bounded concurrency design
lifecycle handling
diagnostics
Node-version test evidence.

Procedure

Read package engines, module mode, lockfile, and runtime flags; preserve ESM or CommonJS conventions.
Design input validation, abort/timeout propagation, backpressure, concurrency limits, and error ownership.
Implement structured errors and graceful startup/shutdown for sockets, pools, workers, and signals.
Test event-loop edge cases, stream failures, cancellation, unhandled rejection policy, and resource cleanup.
Run the pinned Node test, lint, type, package, and diagnostic commands; inspect handles for leaks.

Verification

Verify no open-handle leak, unbounded Promise fan-out, swallowed stream error, or incompatible package export.

Unhappy Paths and Recovery

If the event loop stalls, collect delay and CPU profiles. If a stream corrupts under retry, make replay/idempotency explicit. Stop on unsupported runtime versions.

Concrete Example

Implement a CSV ingestion stream with pipeline backpressure, AbortSignal timeout, bounded writes, rejected-row reporting, and shutdown tests.

Do Not Use This Skill When

Do not use for browser JavaScript or runtime-neutral TypeScript design.

Tradeoffs

The required domain artifacts and verification cost more than a generic implementation pass, but they expose assumptions, safety gates, and operational limits before release.

Anti-Patterns

Substituting a generic checklist for the domain procedure above.
Claiming a gate passed without retaining the exact command, inspected artifact, or observed signal.
Expanding scope or executing an external effect without target-specific approval.

Enterprise Considerations

Apply repository ownership, separation of duties, data residency and retention, audit evidence, and approved-tool policies to every produced artifact. Redact secrets and regulated data from examples and logs.

Checklist

Trigger and anti-trigger evaluated
Required inputs and domain artifacts complete
Procedure followed in order
Verification evidence retained
Recovery, rollback, owner, and residual risk recorded

Authoritative Sources

Changelog

2.0 (2026-07-16): Replaced the cloned generic procedure with domain-specific artifacts, workflow, recovery, examples, and sources.
1.1: Initial standardized structure.