This adapter allows Astro to run your SSR site with the Bun's native API Bun.serve.

• Bun

1. Install astro-bun package

bun add astro-bun

2. Update your astro.config.mjs to use astro-bun adapter.

// astro.config.mjs
import { defineConfig } from 'astro/config';
import bun from 'astro-bun';

export default defineConfig({
  output: 'server',
  adapter: bun(),
});

3. Build your project.

bunx --bun astro build

This will generate an entry.mjs script inside ./dist/server.

4. Run the entry.mjs script.

bun run ./dist/server/entry.mjs

or, you can update the preview script in you package.json.

// package.json
{
  // ...
  "scripts": {
    "dev": "astro dev",
    "start": "astro dev",
    "build": "astro build",
    "preview": "bun run ./dist/server/entry.mjs"
  }
}

and then just run:

bunx --bun astro preview