@sveltejs/adapter-bun

Experimental. Adapter for SvelteKit apps that compiles the app into a Bun single-file executable. All static, prerendered, and server assets are embedded into the binary — the resulting file runs standalone with no external dependencies.

Requirements

• Bun >= 1.2.17 — the build and the resulting binary both run under Bun.
• SvelteKit >= 2.4.0.

Caveats

• No native (N-API) modules in single-file mode. Packages that ship .node addons (sharp, better-sqlite3, argon2, canvas, etc.) cannot be embedded in the executable. WASM works. Native addons do work if you set compile: false.
• Read-only filesystem (single-file mode). Embedded assets live in Bun's $bunfs, which is read-only. Persist any user data outside the binary.
• Not yet supported: service worker embedding, instrumentation hooks, socket activation.

Usage

// svelte.config.js
import adapter from '@sveltejs/adapter-bun';

export default {
  kit: {
    adapter: adapter()
  }
};

Run the build under Bun:

bun run build

Output: build/app (single-file executable).

Skipping the executable

Set compile: false to emit build/entry.js and the asset tree without producing a standalone binary:

adapter({ compile: false });

Then run bun run build/entry.js. This keeps native addons working and makes iteration faster at the cost of shipping Bun alongside the app.

License

MIT