Jsexec

Q: What is a Claude Code skill and how does the Jsexec skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Jsexec is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Engineering category. Learn more at https://claudskills.com/learn/what-is-skill-md/.

Category: Engineering · Sub-category: testing · Last updated: 2026-06-13

lang:javascript

Use whenever you need to RUN Synchronet JavaScript — executing inline JS expressions, running scripts from the install's exec/ directory, testing JS modules, or validating changes to .js/.ssjs/.xjs files against a live install. This skill covers the jsexec runner itself: invocation modes, flags, output capture, crash tracing, and (on Windows) running a freshly-built debug binary. Trigger on "run a Synchronet script", "test this JS against Synchronet", "check what jsexec does", or any one-off JavaScript probe of a live install. For the JavaScript LANGUAGE and host API (how MsgBase/User/FileBase behave, SpiderMonkey dialect, the object model, writing tests, stock exec/*.js) see the javascript skill.

From the source SKILL.md

jsexec is the standalone runner for Synchronet's JavaScript engine (SpiderMonkey 1.8.5). It loads the full Synchronet runtime — config, message bases, file bases, sockets, the system/server/js globals — without requiring a BBS session. It's the fastest way to run a script, probe an object, or validate a code change against a real install.

What this skill does

Jsexec is a community-contributed Claude Code skill in the testing sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/jsexec/ and loads when your prompt matches the skill's trigger.

When to invoke it: Use whenever you need to RUN Synchronet JavaScript — executing inline JS expressions, running scripts from the install's exec/ directory, testing JS modules, or validating changes to .js/.

Who uses this skill

The Jsexec Claude Code skill is built for software engineers, backend developers, full-stack teams, and technical leads building and maintaining production systems. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 119,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).

How to install

Free

Manual install (2 steps)

mkdir -p ~/.claude/skills/jsexec
curl -L https://claudskills.com/skills/jsexec/SKILL.md \
  -o ~/.claude/skills/jsexec/SKILL.md

Or just download SKILL.md directly and drop it into ~/.claude/skills/jsexec/. Claude Code auto-discovers it on next session.

Skills live at ~/.claude/skills/jsexec/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\jsexec\SKILL.md on Windows. See the full install guide for step-by-step instructions.

📱 Install from your phone or desktop Telegram

Open @claudskills_bot on Telegram, tap Open Desktop App, and the desktop app installs this skill for you. Or share the bot link with a colleague — they get the same one-tap install. Learn more →

Pro

One-click install via the desktop app

The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.

Pro

For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.

See pricing → Download desktop app

Frequently asked questions

How do I install the Jsexec Claude Code skill?

Install via the ClaudSkills desktop app (one click) or copy SKILL.md from the source repository to ~/.claude/skills/jsexec/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.

What does the Jsexec skill do?

Is this skill free to install?

Yes. ClaudSkills is an open registry — every skill keeps its source repository's license, and manual install via copy is free. ClaudSkills Pro ($9/mo, $79/yr, or $149 one-time) adds one-click install via the desktop app and a multi-signal Quality Score.

When should I use the Jsexec skill?

Use Jsexec when your Claude Code task falls under the Engineering category — specifically in the testing area. Claude Code auto-discovers installed skills and invokes the right one based on the task description, so you can also ask Claude directly (e.g. "use Jsexec" or describe the task and let Claude pick). Browse related skills at /category/engineering/.

What is a Claude Code skill and how does the Jsexec skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Jsexec is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Engineering category. Learn more at /learn/what-is-a-claude-skill/.

Attribution & license

Source: https://github.com/SynchronetBBS/sbbs/blob/135f08f0f5e1146d28b3c9edca65f4e510abdede/.claude/skills/jsexec/SKILL.md
Author: SynchronetBBS
Website: https://gitlab.synchro.net

Cite this skill

If you reference this skill in a blog post, paper, or documentation, you can cite it as:

APA

SynchronetBBS. (2026). Jsexec [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/jsexec/

BibTeX

@misc{jsexec-2026,
  author    = {SynchronetBBS},
  title     = {Jsexec [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/jsexec/}
}

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