agentmods.dev

bun

A JavaScript and TypeScript runtime with built-in tools for installing packages, bundling code, running tests, serving HTTP, and working with files and databases. It is an alternative to using several separate tools.

In plain words
What is it for?
Use it to run JavaScript or TypeScript, manage packages, bundle applications, run tests, create servers, use SQLite, work with S3 or Redis, and write shell scripts.
Why use it?
It gives JavaScript and TypeScript projects one toolkit for common development tasks. This can reduce the number of separate commands and tools you need to configure.

Skill for Claude CodeCodex

22 1mo ago A scan 111 tokens original MIT
View the source file itechmeat/llm-code
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.

agentmods
npx agentmods add skills/itechmeat/llm-code/bun
Any agent
npx skills add itechmeat/llm-code --skill bun
Clone the repo
git clone --depth 1 https://github.com/itechmeat/llm-code

Made for: Claude Code, Codex.

Per session 111 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,861 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 2 findings. Scan, not verified.
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 $0.00111 $0.01861
Opus 5 $0.00056 $0.00931
Sonnet 5 $0.00022 $0.00372
Haiku 4.5 $0.00011 $0.00186

Measured 2d ago against content hash 00d9cb24a048, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

bun scanned grade A with 2 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 2d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

fetch(req) {

Runs shell commandslowCapability

Expected in a hook, worth knowing in a rule or an instructions file.

| `child_process.exec()` | `Bun.$` or `Bun.spawn()` |
skills/bun/SKILL.md · 260 lines

How it starts

The opening of the file, as written. The whole thing — 260 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Bun

All-in-one JavaScript/TypeScript toolkit: runtime, package manager, test runner, bundler.

Quick Navigation

Topic Reference
Package Manager references/package-manager.md
Project Setup references/project-scaffolding.md
Development references/development.md
Module System references/module-system.md
TypeScript & JSX references/typescript-jsx.md
Configuration references/bunfig.md
HTTP Server references/http-server.md
Browser Automation references/webview.md
WebSockets references/websockets.md
File I/O references/file-io.md
SQLite references/sqlite.md
S3 Storage references/s3.md
Redis references/redis.md
Low-Level Network references/networking-low-level.md
Fetch API references/fetch.md
Shell Scripts references/shell.md
Spawn Process references/spawn.md
Workers references/workers.md
Native FFI references/native-interop.md
C/C++ Compile references/cc.md
Transpiler references/transpiler.md
Plugins references/plugins.md
FS Router references/file-system-router.md
Environment Vars references/env.md
Utilities references/utilities.md
Node.js Compat references/nodejs-compat.md

When to Use Bun

  • Running TypeScript/JSX without build step
  • Fast HTTP server with native routing
  • Headless browser automation with native input events
  • SQLite database (embedded, no deps)
  • WebSocket server/client
  • S3-compatible storage (AWS, R2, MinIO)
  • Redis caching/pub-sub
  • Cross-platform shell scripts
  • In-process cron scheduling
  • Markdown parsing (v1.3.8+)
  • Native library calls via FFI

Read the full file on GitHub · 260 lines

Files

What ships with it

26 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. 2d ago First seen · 260 lines · 111 tokens per session scan A 00d9cb24a048

Subscribe to this mod's changes

bun is a skill published in the GitHub repository itechmeat/llm-code (22 stars, last pushed 1mo ago), licensed MIT. It adds 111 tokens to every session and 1,861 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 2 findings (makes network calls, runs shell commands). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

DatabasesLanguagesTesting
Related

Other skills, from other repositories

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

next-cache-components-adoption

Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…

vercel/next.js · 95 tokens

babysit-pr

Babysit a GitHub pull request after creation by continuously polling review comments, CI checks/workflow runs, and mergeability state until the PR is merged/closed or user help is required. Diagnose failures, retry likely flaky failures up to 3 times, auto-fix/push branch-related issues when appropriate, and keep…

openai/codex · 114 tokens

imagegen

Generate or edit raster images when the task benefits from AI-created bitmap visuals such as photos, illustrations, textures, sprites, mockups, or transparent-background cutouts. Use when Codex should create a brand-new image, transform an existing image, or derive visual variants from references, and the output…

openai/codex · 113 tokens

cpu-profile-analysis

Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…

microsoft/vscode · 71 tokens

next-cache-components-optimizer

Drive a Next.js route to instant navigation by setting up an agentic loop, under Cache Components / PPR, on initial load (hard navigation) and client-side navigation (soft navigation). Encode the goal as a failing @next/playwright instant() e2e and work it to green, one verified route at a time; the shipped test then…

vercel/next.js · 170 tokens