# Javascript Core

> JavaScript skill for runtime correctness, async behavior, module compatibility, and maintainable patterns. Trigger phrases: JavaScript, Node, ESM, CommonJS, promises, async await, event loop, runtime bug.

- **Type:** Skill
- **Install:** `agentstack add skill-caraya-agent-skills-javascript-core`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [caraya](https://agentstack.voostack.com/s/caraya)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [caraya](https://github.com/caraya)
- **Source:** https://github.com/caraya/agent-skills/tree/main/skills/javascript-core

## Install

```sh
agentstack add skill-caraya-agent-skills-javascript-core
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# JavaScript Core Skill

## Use When

- Reviewing or writing JavaScript code.
- Validating async flow, module format, and runtime behavior.
- Checking for common production reliability issues.

## Checklist

1. Runtime correctness
- Validate coercion, equality usage, and nullish handling.
- Confirm error paths and fallback behavior.

2. Async control flow
- Catch missing await and unhandled promises.
- Validate concurrency limits for batch operations.
- Confirm cleanup for timers, streams, and listeners.

3. Module and platform fit
- Check ESM and CommonJS interop assumptions.
- Ensure imports are compatible with runtime target.

4. Code quality
- Prefer clear functions over hidden side effects.
- Keep state changes explicit and testable.

## Output Requirements

For each finding provide:
- Location
- Failure mode
- User impact
- Minimal fix

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [caraya](https://github.com/caraya)
- **Source:** [caraya/agent-skills](https://github.com/caraya/agent-skills)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-caraya-agent-skills-javascript-core
- Seller: https://agentstack.voostack.com/s/caraya
- Browse the marketplace: https://agentstack.voostack.com/browse

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Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.