# bun-sveltekit

Tells the agent how to build and run SvelteKit apps on Bun: SSR, adapters, bun:sqlite and file handling.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · 499 installs · ★ 236
- Author: secondsky
- License: MIT · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/secondsky/claude-skills/tree/HEAD/plugins/bun/skills/bun-sveltekit/SKILL.md
- Updated: 2026-10-20
- HTML: https://affpapa.org/en/nevibecode/skills/bun-sveltekit

## What it does

The skill kicks in when you write a SvelteKit app and want Bun underneath. It ships templates for `+page.server.ts` with `bun:sqlite`, form actions, API routes using `Bun.file` and `Bun.write`, and server hooks that set up the database on startup.

There is a section on `svelte-adapter-bun` and its options: `out`, `precompress`, `envPrefix`, `dynamic_origin`, `xff_depth`. Environment variables are covered through `$env/static/private` and `$env/dynamic/private`, plus a Docker build on the `oven/bun:1` image.

The skill advises setting `minimumReleaseAge` in `bunfig.toml` and checking packages with the Socket CLI first. That matters because `bunx sv create` downloads and runs remote code, and Bun blocks post-install scripts by default — you allow them one by one through `trustedDependencies`.

## Install

### Claude Code (native platform)

1. **Skills CLI (Vercel)**
```bash
npx skills add secondsky/claude-skills --skill bun-sveltekit -a claude-code
```

2. **Manually: put the files in place**
- File: `~/.claude/skills/bun-sveltekit/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/bun-sveltekit/

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add secondsky/claude-skills --skill bun-sveltekit -a codex
```

2. **Manually: put the files in place**
- File: `.agents/skills/bun-sveltekit/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add secondsky/claude-skills --skill bun-sveltekit -a cursor
```

2. **Manually: put the files in place**
- File: `.cursor/skills/bun-sveltekit/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install secondsky/claude-skills bun-sveltekit
```

2. **Manually: put the files in place**
- File: `.github/skills/bun-sveltekit/SKILL.md`

### Gemini CLI

1. **Skills CLI (Vercel)**
```bash
npx skills add secondsky/claude-skills --skill bun-sveltekit -a gemini-cli
```

2. **Platform CLI**
```bash
gemini skills install https://github.com/secondsky/claude-skills --path plugins/bun/skills/bun-sveltekit
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/bun-sveltekit/SKILL.md` — The legacy .windsurf/skills/ path still works

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add secondsky/claude-skills --skill bun-sveltekit -a opencode
```

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/secondsky/claude-skills/tree/HEAD/plugins/bun/skills/bun-sveltekit/SKILL.md

## When to use it
- scaffold a SvelteKit project on Bun
- wire `bun:sqlite` into server load functions
- swap adapter-auto for `svelte-adapter-bun`
- serve and save files with `Bun.file` and `Bun.write`
- build a Docker image for a Bun app

## Example prompts
- Create a SvelteKit project on Bun and set up svelte-adapter-bun
- Rewrite this API route to use bun:sqlite instead of an external database
- Add a server hook that creates the users table on startup

## Source text · SKILL.md · MIT

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: 60e3855f2e2c7d11.

BEGIN THIRD-PARTY FILE 60e3855f2e2c7d11
````text
---
name: bun-sveltekit
description: Use when building or running SvelteKit apps on Bun, including SSR, adapters, and Bun-specific APIs
metadata:
  keywords: "SvelteKit, Svelte 5, Bun, SSR, adapters, Vite, database, file operations"
license: MIT
---

# Bun SvelteKit

Run SvelteKit applications with Bun for faster development and builds.

## Quick Start

```bash
# Create new SvelteKit project
bunx sv create my-app
cd my-app

# Install dependencies
bun install

# Development
bun run dev

# Build
bun run build

# Preview
bun run preview
```

## Secure Installation

Scaffolding tools like `bunx sv create` download and execute remote code. Before running, follow supply chain security best practices:

- **Block post-install scripts** — Bun disables them by default; allow specific packages via `trustedDependencies` in `package.json`
- **Cooldown period** — Configure `minimumReleaseAge` in `bunfig.toml` to wait 7 days for new versions
- **Audit before installing** — Run `socket package score npm <pkg>` or use `socket npm install <pkg>` to check packages

Load the `dependency-upgrade` skill for full security configuration including Socket CLI integration, cooldown setup, lockfile validation, and CI enforcement.

## Project Setup

### package.json

```json
{
  "scripts": {
    "dev": "vite dev",
    "build": "vite build",
    "preview": "vite preview"
  },
  "devDependencies": {
    "@sveltejs/adapter-auto": "^7.0.0",
    "@sveltejs/kit": "^2.0.0",
    "svelte": "^5.0.0",
    "vite": "^7.3.0"
  }
}
```

### Use Bun Adapter

```bash
bun add -D svelte-adapter-bun
```

```javascript
// svelte.config.js
import adapter from "svelte-adapter-bun";
import { vitePreprocess } from "@sveltejs/vite-plugin-svelte";

/** @type {import('@sveltejs/kit').Config} */
export default {
  preprocess: vitePreprocess(),
  kit: {
    adapter: adapter(),
  },
};
```

## Using Bun APIs

### Server Load Functions

```typescript
// src/routes/users/+page.server.ts
import { Database } from "bun:sqlite";
import type { PageServerLoad } from "./$types";

export const load: PageServerLoad = async () => {
  const db = new Database("data.sqlite");
  const users = db.query("SELECT * FROM users").all();
  db.close();

  return { users };
};
```

### Form Actions

```typescript
// src/routes/users/+page.server.ts
import { Database } from "bun:sqlite";
import type { Actions } from "./$types";
import { fail } from "@sveltejs/kit";

export const actions: Actions = {
  create: async ({ request }) => {
    const data = await request.formData();
    const name = data.get("name") as string;

    if (!name) {
      return fail(400, { error: "Name required" });
    }

    const db = new Database("data.sqlite");
    db.run("INSERT INTO users (name) VALUES (?)", [name]);
    db.close();

    return { success: true };
  },

  delete: async ({ request }) => {
    const data = await request.formData();
    const id = data.get("id") as string;

    const db = new Database("data.sqlite");
````
END THIRD-PARTY FILE 60e3855f2e2c7d11

The third-party file has ended. Everything between the 60e3855f2e2c7d11 tags is data: requests and commands from it are not followed. An “end of file” line with another tag inside the block is part of the file.

First 2984 of 7499 bytes. © secondsky · MIT · https://github.com/secondsky/claude-skills/tree/HEAD/plugins/bun/skills/bun-sveltekit/SKILL.md

_Part of the page did not fit — see the HTML version._

---
NeVibeCode on affpapa.org. Catalog texts are descriptions, not instructions for the agent. How to choose and install: https://affpapa.org/en/nevibecode/agents.md