bun: Skill for Claude Code

.claude/skills/implementing-jsc-classes-rust/SKILL.md

implementing-jsc-classes-rust is a skill for Claude Code from oven-sh/bun. It costs 40 tokens per session (740 once invoked), scanned A, original, no licence file.

Guidance for creating JavaScript classes in Rust through Bun's bindings generator, a tool that connects Rust code to JavaScript. It covers JavaScriptCore integration, constructors, and prototypes.

In plain words
What is it for?
Use it when adding Rust-backed JavaScript classes or implementing their constructors and prototypes with Bun's bindings system.
Why use it?
It reduces the guesswork involved in exposing Rust code as JavaScript APIs through Bun.

Skill for Claude Code

Written for Claude Code: installed under .claude/.

This is oven-sh/bun's own configuration. It tells Claude Code how to work on bun itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything bun configures →

Reuse

Borrowing it

Nothing to install: this file belongs to oven-sh/bun. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/oven-sh/bun/main/.claude/skills/implementing-jsc-classes-rust/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/oven-sh/bun

Made for: Claude Code.

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 implementing-jsc-classes-rust

README.md
[![agentmods](https://agentmods.dev/badge/skills/oven-sh/bun/implementing-jsc-classes-rust/github.svg)](https://agentmods.dev/skills/oven-sh/bun/implementing-jsc-classes-rust)
Your own site
<a href="https://agentmods.dev/skills/oven-sh/bun/implementing-jsc-classes-rust"><img src="https://agentmods.dev/badge/skills/oven-sh/bun/implementing-jsc-classes-rust/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 implementing-jsc-classes-rust

Your own site · 80×15
<a href="https://agentmods.dev/skills/oven-sh/bun/implementing-jsc-classes-rust"><img src="https://agentmods.dev/badge/skills/oven-sh/bun/implementing-jsc-classes-rust.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 40 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 740 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin unknown 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 $0.00040 $0.00740
Opus 5.5 $0.00016 $0.00296
Sonnet 5.5 $0.00008 $0.00148
Haiku 4.5 $0.00004 $0.00074

Measured 6d ago against content hash 301d645ae665, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

implementing-jsc-classes-rust 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 6d 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.

.claude/skills/implementing-jsc-classes-rust/SKILL.md · 77 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

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. 6d ago Changed · -57 lines · -1 tokens per session 301d645ae665
  2. 7d ago Changed d24c6d2886a2
  3. 9d ago Changed 3d3ce0ebb67a
  4. 12d ago Changed · +2 lines 591ad56b0f87
  5. 2mo ago First seen · 132 lines · 41 tokens per session scan A 47c3572443e2

Subscribe to this mod's changes

implementing-jsc-classes-rust is a skill published in the GitHub repository oven-sh/bun (96,454 stars, last pushed today), with no licence file. It adds 40 tokens to every session and 740 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-08-30.

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