Borrowing it
Nothing to install: this file belongs to saski/arnesto. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/saski/arnesto/main/.agents/skills/bun-toolkit/SKILL.mdgit clone --depth 1 https://github.com/saski/arnestoWrote 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.
[](https://agentmods.dev/skills/saski/arnesto/bun-toolkit)<a href="https://agentmods.dev/skills/saski/arnesto/bun-toolkit"><img src="https://agentmods.dev/badge/skills/saski/arnesto/bun-toolkit.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00037 | $0.00437 |
| Opus 5 | $0.00018 | $0.00218 |
| Sonnet 5 | $0.00007 | $0.00087 |
| Haiku 4.5 | $0.00004 | $0.00044 |
Grade A, and why
bun-toolkit scanned grade A with 1 finding 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
- **HTTP Server**: Use `Bun.serve({ fetch(req) { ... } })` for an extremely fast built-in web server. What it actually says
Bun Toolkit
Bun is a fast, all-in-one JavaScript runtime and toolkit.
Core Features
- Runtime: Fast JS/TS runtime, drop-in replacement for Node.js.
- Package Manager:
bun installis significantly faster thannpmoryarn. - Test Runner:
bun testprovides a fast, Jest-compatible testing environment. - Bundler:
bun buildfor bundling JS/TS for the web or other runtimes.
Common Commands
bun init # Start a new project
bun install # Install dependencies
bun add <package> # Add a package
bun run <script> # Run a package.json script
bun <file.ts> # Run a TS/JS file directly
bun test # Run tests
bun build ./index.ts --outdir ./build # Build for production
Awareness & Best Practices
- TypeScript Support: Bun supports
.tsand.tsxfiles out of the box. No separate compilation step needed. - Environment Variables: Automatically loads
.envfiles. Access viaprocess.envorBun.env. - Fast I/O: Use
Bun.file(path)andBun.write(path, content)for high-performance file operations. - HTTP Server: Use
Bun.serve({ fetch(req) { ... } })for an extremely fast built-in web server. - SQLite: Built-in high-performance SQLite driver via
import { Database } from "bun:sqlite".
When to use Bun Toolkit
- When the project has a
bun.lockbfile. - When the user mentions "Bun".
- When performance is a priority for JS/TS tasks (installing, testing, running).
- For quick JS/TS scripts that need high performance.
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.
- 6d ago First seen · 42 lines · 37 tokens per session scan A 2f475d71b426
bun-toolkit is a skill published in the GitHub repository saski/arnesto (5 stars, last pushed today), licensed Unlicense. It adds 37 tokens to every session and 437 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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