sveltekit-extension-template/svelte.config.js

import adapter from 'sveltekit-adapter-chrome-extension';

/** @type {import('@sveltejs/kit').Config} */
const config = {
	kit: {
		// adapter-auto only supports some environments, see https://kit.svelte.dev/docs/adapter-auto for a list.
		// If your environment is not supported or you settled on a specific environment, switch out the adapter.
		// See https://kit.svelte.dev/docs/adapters for more information about adapters.
		adapter: adapter({
			// default options are shown
			pages: 'build',
			assets: 'build',
			fallback: null,
			precompress: false,
			manifest: 'manifest.json'
		}),
		appDir: 'app'
	}
};

export default config;