diff --git a/.changeset/smooth-flies-begin.md b/.changeset/smooth-flies-begin.md
new file mode 100644
index 000000000000..80d6c5efc17a
--- /dev/null
+++ b/.changeset/smooth-flies-begin.md
@@ -0,0 +1,10 @@
+---
+"@sveltejs/adapter-cloudflare": major
+"@sveltejs/adapter-netlify": major
+"@sveltejs/adapter-node": major
+"@sveltejs/adapter-vercel": major
+"@sveltejs/kit": major
+---
+
+breaking: replace the `builder.generateManifest` with `builder.generateServerInstance` and `builder.manifest`
+  
\ No newline at end of file
diff --git a/documentation/docs/25-build-and-deploy/99-writing-adapters.md b/documentation/docs/25-build-and-deploy/99-writing-adapters.md
index a4002696a018..77be9c8aeeb4 100644
--- a/documentation/docs/25-build-and-deploy/99-writing-adapters.md
+++ b/documentation/docs/25-build-and-deploy/99-writing-adapters.md
@@ -60,8 +60,8 @@ Within the `adapt` method, there are a number of things that an adapter should d
 - Clear out the build directory
 - Write SvelteKit output with `builder.writeClient`, `builder.writeServer`, and `builder.writePrerendered`
 - Output code that:
-	- Imports `Server` from `${builder.getServerDirectory()}/index.js`
-	- Instantiates the app with a manifest generated with `builder.generateManifest({ relativePath })`
+	- Imports a `server` instance generated by `${builder.generateServerInstance()}`
+	- Runs `await server.init({ env, read })`
 	- Listens for requests from the platform, converts them to a standard [`Request`](https://developer.mozilla.org/en-US/docs/Web/API/Request) if necessary, calls the `server.respond(request, { getClientAddress })` function to generate a [`Response`](https://developer.mozilla.org/en-US/docs/Web/API/Response) and responds with it
 	- expose any platform-specific information to SvelteKit via the `platform` option passed to `server.respond`
 - Bundle the output to avoid needing to install dependencies on the target platform, if necessary
diff --git a/documentation/docs/60-appendix/35-migrating-to-sveltekit-3.md b/documentation/docs/60-appendix/35-migrating-to-sveltekit-3.md
index 71426de4b435..d99fb5dbb27d 100644
--- a/documentation/docs/60-appendix/35-migrating-to-sveltekit-3.md
+++ b/documentation/docs/60-appendix/35-migrating-to-sveltekit-3.md
@@ -481,6 +481,7 @@ For adapter authors, there are some additional changes:
 - `builder.createEntries` has been removed — use `builder.writeClient`, `builder.writeServer` and `builder.writePrerendered` directly
 - `builder.compress` returns a list of compressed files
 - `builder.mkdirp` and `builder.rimraf` are deprecated in favour of `node:fs` methods
+- `builder.generateManifest` has been removed — use `builder.generateServerInstance` to replace it, and `builder.manifest` to access the manifest
 
 ## Responses
 
diff --git a/packages/adapter-bun/index.js b/packages/adapter-bun/index.js
index abb7579f3f57..ae34a56c7230 100644
--- a/packages/adapter-bun/index.js
+++ b/packages/adapter-bun/index.js
@@ -136,9 +136,13 @@ export default function (opts = {}) {
 			const manifest_file = path.resolve(server, 'manifest.js');
 			const server_options_file = path.resolve(src_dir, 'options.js');
 
+			const tmp = builder.getBuildDirectory('bun-tmp');
+			fs.mkdirSync(tmp, { recursive: true });
+			builder.generateServerInstance(`${tmp}/server.js`);
+
 			const virtual_files = {
 				[manifest_file]:
-					`export const manifest = ${builder.generateManifest({ relativePath: './' })};\n` +
+					`export const app_dir = ${JSON.stringify(builder.config.appDir)};\n` +
 					`export const base = ${JSON.stringify(builder.config.paths.base || '/')};\n` +
 					`export const embed = ${JSON.stringify(!!buildOptions.compile)};\n` +
 					`export const env_prefix = ${JSON.stringify(envPrefix)};\n` +
@@ -198,7 +202,7 @@ export default function (opts = {}) {
 				name: 'adapter-bun',
 				setup(build) {
 					build.onResolve({ filter: /^(SERVER|MANIFEST|ROUTES|SERVER_OPTIONS)$/ }, ({ path }) => {
-						if (path === 'SERVER') return { path: `${server}/index.js` };
+						if (path === 'SERVER') return { path: `${tmp}/server.js` };
 						if (path === 'MANIFEST') return { path: manifest_file };
 						if (path === 'ROUTES') return { path: routes_file };
 						if (path === 'SERVER_OPTIONS') return { path: server_options_file };
diff --git a/packages/adapter-bun/internal.d.ts b/packages/adapter-bun/internal.d.ts
index b3e0ceed137a..ce532903b579 100644
--- a/packages/adapter-bun/internal.d.ts
+++ b/packages/adapter-bun/internal.d.ts
@@ -1,5 +1,5 @@
 declare module 'MANIFEST' {
-	export const manifest: import('@sveltejs/kit').SSRManifest;
+	export const app_dir: string;
 	export const base: string;
 	export const embed: boolean;
 	export const env_prefix: string;
@@ -12,7 +12,7 @@ declare module 'ROUTES' {
 }
 
 declare module 'SERVER' {
-	export { Server } from '@sveltejs/kit';
+	export const server: import('@sveltejs/kit').Server;
 }
 
 declare module 'SERVER_OPTIONS' {
diff --git a/packages/adapter-bun/src/handler.js b/packages/adapter-bun/src/handler.js
index d773849f2d56..6fa5d8c9a18a 100644
--- a/packages/adapter-bun/src/handler.js
+++ b/packages/adapter-bun/src/handler.js
@@ -1,11 +1,9 @@
 /** @import { Server as BunServer } from 'bun' */
-import { Server } from 'SERVER';
-import { manifest, origin, env_prefix } from 'MANIFEST';
+import { server } from 'SERVER';
+import { origin, env_prefix } from 'MANIFEST';
 import { server_assets } from 'ROUTES';
 import { env, number_env } from './env.js';
 
-const server = new Server(manifest);
-
 const address_header = env('ADDRESS_HEADER', '').toLowerCase();
 const protocol_header = env('PROTOCOL_HEADER', '').toLowerCase();
 const host_header = env('HOST_HEADER', '').toLowerCase();
diff --git a/packages/adapter-bun/src/routes-util.js b/packages/adapter-bun/src/routes-util.js
index 942165cbdc13..3017e26a38f1 100644
--- a/packages/adapter-bun/src/routes-util.js
+++ b/packages/adapter-bun/src/routes-util.js
@@ -1,5 +1,5 @@
 /** @import { BunFile, BunRequest, Serve } from 'bun' */
-import { manifest, base, embed } from 'MANIFEST';
+import { app_dir, base, embed } from 'MANIFEST';
 import path from 'node:path';
 import { fileURLToPath } from 'node:url';
 
@@ -174,7 +174,7 @@ function file_route(file, meta, extra_headers = {}) {
  * @returns {Array<[string, RouteHandler]>}
  */
 export function client_asset(url, filename = url, meta) {
-	const immutable = url.startsWith(`${manifest.appDir}/immutable/`);
+	const immutable = url.startsWith(`${app_dir}/immutable/`);
 	const route = file_route(
 		resolve_file('client', filename),
 		meta,
diff --git a/packages/adapter-bun/test/adapter.spec.ts b/packages/adapter-bun/test/adapter.spec.ts
index a5963fa9f94f..f5fa75f984c5 100644
--- a/packages/adapter-bun/test/adapter.spec.ts
+++ b/packages/adapter-bun/test/adapter.spec.ts
@@ -121,7 +121,7 @@ describe('Bun build configuration', () => {
 
 		const files = bun_build.mock.calls[0][0].files;
 		expect(files[manifest_file]).toBe(
-			'export const manifest = {"appDir":"_app"};\n' +
+			'export const app_dir = "_app";\n' +
 				'export const base = "/docs";\n' +
 				'export const embed = false;\n' +
 				'export const env_prefix = "APP_";\n' +
@@ -130,7 +130,9 @@ describe('Bun build configuration', () => {
 		expect(files[options_file]).toBe(
 			'export default {"hostname":"127.0.0.1","port":4000,"development":true};'
 		);
-		expect(builder.generateManifest).toHaveBeenCalledWith({ relativePath: './' });
+		expect(builder.generateServerInstance).toHaveBeenCalledWith(
+			'.svelte-kit/output/bun-tmp/server.js'
+		);
 	});
 
 	test('resolves generated runtime modules through the Bun plugin', async () => {
@@ -144,7 +146,7 @@ describe('Bun build configuration', () => {
 		);
 		const resolve_module = on_resolve.mock.calls[0][1];
 		expect(resolve_module({ path: 'SERVER' })).toEqual({
-			path: '.svelte-kit/output/server/index.js'
+			path: '.svelte-kit/output/bun-tmp/server.js'
 		});
 		expect(resolve_module({ path: 'MANIFEST' })).toEqual({ path: manifest_file });
 		expect(resolve_module({ path: 'ROUTES' })).toEqual({ path: routes_file });
@@ -576,7 +578,7 @@ function create_builder({
 	instrumentation?: boolean;
 } = {}) {
 	return {
-		config: { outDir: '.svelte-kit', paths: { base, origin } },
+		config: { outDir: '.svelte-kit', paths: { base, origin }, appDir: '_app' },
 		routes,
 		prerendered: {
 			pages: new Map(prerendered_pages),
@@ -588,6 +590,9 @@ function create_builder({
 			warn: mock((_message: string) => {}),
 			info: mock((_message: string) => {})
 		},
+		getAppPath: () => `${base}/_app`,
+		generateServerInstance: mock(() => {}),
+		getBuildDirectory: (dir: string) => `.svelte-kit/output/${dir}`,
 		getServerDirectory: () => '.svelte-kit/output/server',
 		writeClient: mock(() => client_files),
 		writePrerendered: mock(() => prerendered_files),
diff --git a/packages/adapter-bun/test/handler.spec.ts b/packages/adapter-bun/test/handler.spec.ts
index bc1bd272827f..7735ede19973 100644
--- a/packages/adapter-bun/test/handler.spec.ts
+++ b/packages/adapter-bun/test/handler.spec.ts
@@ -14,7 +14,6 @@ afterEach(() => {
 test('initializes SvelteKit with Bun environment variables and server-readable assets', async () => {
 	const loaded = await load_handler();
 
-	expect(loaded.construct).toHaveBeenCalledWith(loaded.manifest);
 	expect(loaded.init).toHaveBeenCalledWith({
 		env: Bun.env,
 		read: expect.any(Function)
@@ -196,23 +195,18 @@ async function load_handler({
 	envPrefix = '',
 	response = new Response('ok')
 }: { origin?: string; envPrefix?: string; response?: Response } = {}) {
-	const manifest = { appDir: '_app' };
 	const stream = new ReadableStream();
 	const asset = { stream: mock(() => stream) };
-	const construct = mock((_value: unknown) => {});
 	const init = mock(async (_options: any) => {});
 	const respond = mock(async (_request: Request, _options: any) => response);
 
 	class Server {
-		constructor(value: unknown) {
-			construct(value);
-		}
 		init = init;
 		respond = respond;
 	}
 
-	mock.module('SERVER', () => ({ Server }));
-	mock_manifest({ manifest, origin, env_prefix: envPrefix });
+	mock.module('SERVER', () => ({ server: new Server() }));
+	mock_manifest({ app_dir: '_app', origin, env_prefix: envPrefix });
 	mock_routes({ server_assets: new Map([['asset.txt', asset]]) });
 
 	const request_ip = mock((_request: Request): any => ({
@@ -227,9 +221,7 @@ async function load_handler({
 
 	return {
 		handler,
-		manifest,
 		stream,
-		construct,
 		init,
 		respond,
 		request_ip,
diff --git a/packages/adapter-bun/test/mocks.ts b/packages/adapter-bun/test/mocks.ts
index 150e00cbd4d4..d1366ccad4b3 100644
--- a/packages/adapter-bun/test/mocks.ts
+++ b/packages/adapter-bun/test/mocks.ts
@@ -5,19 +5,19 @@ import { mock } from 'bun:test';
 // exports that src modules pull from these build-generated specifiers
 
 export function mock_manifest({
-	manifest,
+	app_dir,
 	base,
 	embed,
 	origin,
 	env_prefix = ''
 }: {
-	manifest?: unknown;
+	app_dir?: string;
 	base?: string;
 	embed?: boolean;
 	origin?: string;
 	env_prefix?: string;
 } = {}) {
-	mock.module('MANIFEST', () => ({ manifest, base, embed, origin, env_prefix }));
+	mock.module('MANIFEST', () => ({ app_dir, base, embed, origin, env_prefix }));
 }
 
 export function mock_routes({
diff --git a/packages/adapter-bun/test/routes.spec.ts b/packages/adapter-bun/test/routes.spec.ts
index 1c736217457c..23fbc87a94c0 100644
--- a/packages/adapter-bun/test/routes.spec.ts
+++ b/packages/adapter-bun/test/routes.spec.ts
@@ -78,7 +78,7 @@ test('a root deployment registers routes with a leading slash', async () => {
 });
 
 test('immutable SvelteKit assets receive a long-lived cache policy', async () => {
-	const { routes } = await load_routes({ appDir: '_app' });
+	const { routes } = await load_routes({ app_dir: '_app' });
 
 	const request = new Request('http://localhost/');
 	const immutable = (
@@ -283,8 +283,8 @@ test('prerendered redirects retain their status and location', async () => {
 	expect((handler as any).GET.headers.get('location')).toBe('/new');
 });
 
-async function load_routes({ base = '/', embed = false, appDir = '_app' } = {}) {
-	mock_manifest({ manifest: { appDir }, base, embed });
+async function load_routes({ base = '/', embed = false, app_dir = '_app' } = {}) {
+	mock_manifest({ app_dir, base, embed });
 	// the real Bun.file runs, with the spy recording resolved paths; the files it
 	// points at need not exist because nothing reads their contents
 	const file = spyOn(Bun, 'file');
diff --git a/packages/adapter-cloudflare/files/internal.d.ts b/packages/adapter-cloudflare/files/internal.d.ts
index 6c79569f7f7f..d3e8d81fe7e8 100644
--- a/packages/adapter-cloudflare/files/internal.d.ts
+++ b/packages/adapter-cloudflare/files/internal.d.ts
@@ -1,12 +1,17 @@
 declare module 'SERVER' {
-	export { Server } from '@sveltejs/kit';
+	export const server: import('@sveltejs/kit').Server;
 }
 
-declare module 'MANIFEST' {
-	import { SSRManifest } from '@sveltejs/kit';
-
-	export const manifest: SSRManifest;
-	export const prerendered: Set<string>;
-	export const app_path: string;
-	export const base_path: string;
+namespace Cloudflare {
+	interface Env {
+		ASSETS_BINDING: {
+			fetch: typeof fetch;
+		};
+		[key: string]: string | undefined;
+	}
 }
+
+declare const BASE_PATH: string;
+declare const APP_PATH: string;
+declare const PRERENDERED: Set<string>;
+declare const MANIFEST_ASSETS: Set<string>;
diff --git a/packages/adapter-cloudflare/files/worker.js b/packages/adapter-cloudflare/files/worker.js
index 911af0cfb971..47b478476762 100644
--- a/packages/adapter-cloudflare/files/worker.js
+++ b/packages/adapter-cloudflare/files/worker.js
@@ -1,13 +1,12 @@
-import { Server } from 'SERVER';
-import { manifest, prerendered, base_path } from 'MANIFEST';
+import { server } from 'SERVER';
 import { env } from 'cloudflare:workers';
 
-const server = new Server(manifest);
+const base_path = BASE_PATH;
+const assets = MANIFEST_ASSETS;
+const prerendered = PRERENDERED;
 
-const app_path = `/${manifest.appPath}`;
-
-const immutable = `${app_path}/immutable/`;
-const version_file = `${app_path}/version.json`;
+const immutable = `/${APP_PATH}/immutable/`;
+const version_file = `/${APP_PATH}/version.json`;
 
 /**
  * We don't know the origin until we receive a request, but
@@ -17,11 +16,10 @@ const version_file = `${app_path}/version.json`;
 let origin;
 
 const initialized = server.init({
-	env: /** @type {Record<string, string>} */ (env),
+	env,
 	read: async (file) => {
 		const url = `${origin}/${file}`;
-		const response =
-			await /** @type {{ ASSETS: { fetch: typeof fetch } }} */ (env).ASSETS.fetch(url);
+		const response = await env.ASSETS_BINDING.fetch(url);
 
 		if (!response.ok) {
 			throw new Error(
@@ -33,13 +31,8 @@ const initialized = server.init({
 	}
 });
 
+/** @type {import('@cloudflare/workers-types').ExportedHandler<Cloudflare.Env>} */
 export default {
-	/**
-	 * @param {Request} req
-	 * @param {{ ASSETS: { fetch: typeof fetch } }} env
-	 * @param {ExecutionContext} ctx
-	 * @returns {Promise<Response>}
-	 */
 	async fetch(req, env, ctx) {
 		if (!origin) {
 			origin = new URL(req.url).origin;
@@ -61,8 +54,7 @@ export default {
 		let is_static_asset = false;
 		const filename = stripped_pathname.slice(base_path.length + 1);
 		if (filename) {
-			is_static_asset =
-				manifest.assets.has(filename) || manifest.assets.has(filename + '/index.html');
+			is_static_asset = assets.has(filename) || assets.has(filename + '/index.html');
 		}
 
 		let location = pathname.at(-1) === '/' ? stripped_pathname : pathname + '/';
@@ -73,7 +65,7 @@ export default {
 			pathname === version_file ||
 			pathname.startsWith(immutable)
 		) {
-			let res = await env.ASSETS.fetch(req);
+			let res = await env.ASSETS_BINDING.fetch(req);
 			// `_headers` applies cache regardless of status, so we need to ensure an
 			// error response does not get cached
 			if (res.status >= 400) {
diff --git a/packages/adapter-cloudflare/index.js b/packages/adapter-cloudflare/index.js
index d137538e7194..74e90850e1fe 100644
--- a/packages/adapter-cloudflare/index.js
+++ b/packages/adapter-cloudflare/index.js
@@ -103,12 +103,7 @@ export default function (options = {}) {
 
 			// worker
 			const worker_dest_dir = path.dirname(worker_dest);
-			writeFileSync(
-				`${tmp}/manifest.js`,
-				`export const manifest = ${builder.generateManifest({ relativePath: path.posix.relative(tmp, builder.getServerDirectory()) })};\n\n` +
-					`export const prerendered = new Set(${JSON.stringify(builder.prerendered.paths)});\n\n` +
-					`export const base_path = ${JSON.stringify(builder.config.paths.base)};\n`
-			);
+			builder.generateServerInstance(`${tmp}/server.js`);
 			builder.copy(`${files}/worker.js`, worker_dest, {
 				replace: {
 					// the paths returned by the Wrangler config might be Windows paths,
@@ -116,9 +111,12 @@ export default function (options = {}) {
 					// will be interpreted as escape characters and create an incorrect import path.
 					// We also need to ensure the relative imports start with ./ since Wrangler
 					// errors if a relative import looks like a package import
-					SERVER: `./${posixify(path.relative(worker_dest_dir, builder.getServerDirectory()))}/index.js`,
-					MANIFEST: `./${posixify(path.relative(worker_dest_dir, tmp))}/manifest.js`,
-					ASSETS: assets_binding
+					SERVER: `./${posixify(path.relative(worker_dest_dir, tmp))}/server.js`,
+					BASE_PATH: JSON.stringify(builder.config.paths.base),
+					APP_PATH: JSON.stringify(builder.getAppPath()),
+					MANIFEST_ASSETS: `new Set(${JSON.stringify(builder.manifest.assets.map((a) => a.path))})`,
+					PRERENDERED: `new Set(${JSON.stringify(builder.prerendered.paths)})`,
+					ASSETS_BINDING: assets_binding
 				}
 			});
 			if (builder.hasServerInstrumentationFile()) {
diff --git a/packages/adapter-netlify/files/edge.js b/packages/adapter-netlify/files/edge.js
index 518593892b06..b38d8b34e1cd 100644
--- a/packages/adapter-netlify/files/edge.js
+++ b/packages/adapter-netlify/files/edge.js
@@ -1,7 +1,4 @@
-import { Server } from '0SERVER';
-import { manifest } from 'MANIFEST';
-
-const server = new Server(manifest);
+import { server } from '0SERVER';
 
 /**
  * We don't know the origin until we receive a request, but
diff --git a/packages/adapter-netlify/files/serverless.js b/packages/adapter-netlify/files/serverless.js
index 56502dc95c6c..7397719ef335 100644
--- a/packages/adapter-netlify/files/serverless.js
+++ b/packages/adapter-netlify/files/serverless.js
@@ -1,14 +1,11 @@
-import { Server } from '0SERVER';
 import { createReadableStream } from '@sveltejs/kit/node';
 import process from 'node:process';
 
 /**
- * @param {import('@sveltejs/kit').SSRManifest} manifest
+ * @param {import('@sveltejs/kit').Server} server
  * @returns {(request: Request, context: import('@netlify/types').Context) => Promise<Response>}
  */
-export function init(manifest) {
-	const server = new Server(manifest);
-
+export function init(server) {
 	/** @type {Promise<void> | null} */
 	let init_promise = server.init({
 		env: process.env,
diff --git a/packages/adapter-netlify/index.js b/packages/adapter-netlify/index.js
index c08cda021813..a0708832a35c 100644
--- a/packages/adapter-netlify/index.js
+++ b/packages/adapter-netlify/index.js
@@ -1,6 +1,6 @@
 import { existsSync, mkdirSync, readdirSync, readFileSync, rmSync, writeFileSync } from 'node:fs';
-import { join, posix } from 'node:path';
-import { fileURLToPath, pathToFileURL } from 'node:url';
+import { join } from 'node:path';
+import { fileURLToPath } from 'node:url';
 import { builtinModules } from 'node:module';
 import process from 'node:process';
 import toml from '@iarna/toml';
@@ -264,12 +264,12 @@ function write_frameworks_config({ builder }) {
  * }} opts
  */
 function generate_serverless_function({ builder, routes, patterns, name, type, exclude }) {
-	const manifest = builder.generateManifest({
-		relativePath: '../server',
-		routes
+	builder.generateServerInstance(`.netlify/v1/server-${name}.js`, {
+		routes,
+		serverDirectory: '.netlify/v1/server'
 	});
 
-	const fn = generate_serverless_function_module(manifest, type);
+	const fn = generate_serverless_function_module(name, type);
 	const config = generate_config_export(name, patterns, exclude);
 
 	if (builder.hasServerInstrumentationFile()) {
@@ -288,11 +288,11 @@ function generate_serverless_function({ builder, routes, patterns, name, type, e
 }
 
 /**
- * @param {string} manifest
+ * @param {string} name
  * @param {ServerlessFunctionType} type
  * @returns {string}
  */
-function generate_serverless_function_module(manifest, type) {
+function generate_serverless_function_module(name, type) {
 	if (type === 'catch-all') {
 		// Netlify encodes the response body but `fetch` automatically decodes it.
 		// So, we need to remove the `content-encoding` header to allow Netlify
@@ -300,10 +300,11 @@ function generate_serverless_function_module(manifest, type) {
 		return `\
 import { applyReroute } from '@sveltejs/kit/adapter';
 import { init } from '../serverless.js';
+import { server } from '../server-${name}.js';
 
 const original_url_header = \`x-sveltekit-original-url-\${process.env.NETLIFY_FUNCTIONS_TOKEN}\`
 
-const respond = init(${manifest});
+const respond = init(server);
 
 export default async (request, context) => {
 	const catch_all_response = await respond(request, context);
@@ -329,10 +330,11 @@ export default async (request, context) => {
 	if (type === 'split') {
 		return `\
 import { init } from '../serverless.js';
+import { server } from '../server-${name}.js';
 
 const original_url_header = \`x-sveltekit-original-url-\${process.env.NETLIFY_FUNCTIONS_TOKEN}\`
 
-const respond = init(${manifest});
+const respond = init(server);
 
 export default async (request, context) => {
 	if (request.headers.has(original_url_header)) {
@@ -348,8 +350,9 @@ export default async (request, context) => {
 
 	return `\
 import { init } from '../serverless.js';
+import { server } from '../server-${name}.js';
 
-export default init(${manifest});
+export default init(server);
 `;
 }
 
@@ -422,23 +425,14 @@ async function generate_edge_functions({ builder }) {
 	mkdirSync('.netlify/v1/edge-functions', { recursive: true });
 
 	builder.log.minor('Generating Edge Function...');
-	const relativePath = posix.relative(tmp, builder.getServerDirectory());
 
 	builder.copy(`${files}/edge.js`, `${tmp}/entry.js`, {
 		replace: {
-			'0SERVER': `${relativePath}/index.js`,
-			MANIFEST: './manifest.js'
+			'0SERVER': `./server.js`
 		}
 	});
 
-	const manifest = builder.generateManifest({
-		relativePath
-	});
-
-	writeFileSync(`${tmp}/manifest.js`, `export const manifest = ${manifest};\n`);
-
-	/** @type {{ assets: Set<string> }} */
-	const { assets } = (await import(pathToFileURL(`${tmp}/manifest.js`).href)).manifest;
+	builder.generateServerInstance(`${tmp}/server.js`);
 
 	const path = '/*';
 	// We only need to specify paths without the trailing slash because
@@ -449,7 +443,7 @@ async function generate_edge_functions({ builder }) {
 		`/${builder.getAppPath()}/version.json`,
 		// the base root and `trailingSlash: 'always'` pages are recorded with a trailing slash
 		...builder.prerendered.paths.map((path) => (path === '/' ? path : path.replace(/\/$/, ''))),
-		...Array.from(assets).flatMap((asset) => {
+		...Array.from(builder.manifest.assets).flatMap(({ path: asset }) => {
 			if (asset.endsWith('/index.html')) {
 				const dir = asset.replace(/\/index\.html$/, '');
 				return [`${builder.config.paths.base}/${asset}`, `${builder.config.paths.base}/${dir}`];
diff --git a/packages/adapter-netlify/internal.d.ts b/packages/adapter-netlify/internal.d.ts
index 55da8ba1fbf5..97df9e32dfe3 100644
--- a/packages/adapter-netlify/internal.d.ts
+++ b/packages/adapter-netlify/internal.d.ts
@@ -1,9 +1,3 @@
 declare module '0SERVER' {
-	export { Server } from '@sveltejs/kit';
-}
-
-declare module 'MANIFEST' {
-	import { SSRManifest } from '@sveltejs/kit';
-
-	export const manifest: SSRManifest;
+	export const server: import('@sveltejs/kit').Server;
 }
diff --git a/packages/adapter-node/index.d.ts b/packages/adapter-node/index.d.ts
index 71daeab1361c..4166b9c9b3ae 100644
--- a/packages/adapter-node/index.d.ts
+++ b/packages/adapter-node/index.d.ts
@@ -5,6 +5,11 @@ declare global {
 	const ENV_PREFIX: string;
 	const PRECOMPRESS: boolean;
 	const ORIGIN: string | undefined;
+	const UNCOMPRESSED_EXTENSIONS: Set<string>;
+	const BASE_PATH: string;
+	const APP_PATH: string;
+	const PRERENDERED: Set<string>;
+	const MIME_TYPES: Record<string, string>;
 }
 
 interface AdapterOptions {
diff --git a/packages/adapter-node/index.js b/packages/adapter-node/index.js
index 4ce90cf944c7..f1e4725e5640 100644
--- a/packages/adapter-node/index.js
+++ b/packages/adapter-node/index.js
@@ -1,4 +1,4 @@
-import { mkdirSync, readFileSync, rmSync, writeFileSync } from 'node:fs';
+import { mkdirSync, readFileSync, rmSync } from 'node:fs';
 import { extname } from 'node:path';
 import { fileURLToPath } from 'node:url';
 import { rolldown } from 'rolldown';
@@ -65,16 +65,6 @@ export default function (opts = {}) {
 
 			const dir_id = `${entries}/dir.js`;
 
-			writeFileSync(
-				`${server}/manifest.js`,
-				[
-					`export const manifest = ${builder.generateManifest({ relativePath: './' })};`,
-					`export const prerendered = new Set(${JSON.stringify(builder.prerendered.paths)});`,
-					`export const base = ${JSON.stringify(builder.config.paths.base)};`,
-					`export const uncompressed_extensions = new Set(${JSON.stringify([...uncompressed_extensions])});`
-				].join('\n\n')
-			);
-
 			/** @type {Record<string, string>} */
 			const input = {
 				index: `${entries}/index.js`,
@@ -86,6 +76,20 @@ export default function (opts = {}) {
 				input['instrumentation.server'] = `${server}/instrumentation.server.js`;
 			}
 
+			builder.generateServerInstance(`${server}/server.js`);
+
+			/** @type {Record<string, string>} */
+			const defines = {
+				UNCOMPRESSED_EXTENSIONS: `new Set(${JSON.stringify([...uncompressed_extensions])})`,
+				BASE_PATH: JSON.stringify(builder.config.paths.base),
+				APP_PATH: JSON.stringify(builder.getAppPath()),
+				PRERENDERED: `new Set(${JSON.stringify(builder.prerendered.paths)})`,
+				MIME_TYPES: JSON.stringify(builder.mimeTypes),
+				ORIGIN: JSON.stringify(builder.config.paths.origin) || 'undefined',
+				ENV_PREFIX: JSON.stringify(envPrefix),
+				PRECOMPRESS: JSON.stringify(precompress)
+			};
+
 			// we bundle the Vite output so that deployments only need
 			// their production dependencies. Anything in devDependencies
 			// will get included in the bundled code
@@ -111,9 +115,11 @@ export default function (opts = {}) {
 					{
 						// resolve the app's server and manifest, generated above
 						name: 'adapter-node-resolve-app',
-						resolveId(id) {
-							if (id === 'SERVER') return `${server}/index.js`;
-							if (id === 'MANIFEST') return `${server}/manifest.js`;
+						resolveId: {
+							filter: { id: /^SERVER$/ },
+							handler() {
+								return `${server}/server.js`;
+							}
 						}
 					},
 					{
@@ -125,13 +131,13 @@ export default function (opts = {}) {
 							filter: { id: new RegExp(escape_regex(entries)) },
 							handler(_code, _id, { magicString }) {
 								if (!magicString) throw new Error('experimental.nativeMagicString is not enabled');
-								magicString
-									.replace(/\bENV_PREFIX\b/g, JSON.stringify(envPrefix))
-									.replace(/\bPRECOMPRESS\b/g, JSON.stringify(precompress))
-									.replace(
-										/\bORIGIN\b/g,
-										JSON.stringify(builder.config.paths.origin) || 'undefined'
-									);
+
+								for (const [from, to] of Object.entries(defines)) {
+									// remove $& and $N substitutions by replacing every $ with $$
+									const value = to.replace(/\$/g, '$$$$');
+									magicString.replace(new RegExp(`\\b${from}\\b`, 'g'), value);
+								}
+
 								return {
 									code: magicString,
 									map: magicString.generateMap().toString()
diff --git a/packages/adapter-node/internal.d.ts b/packages/adapter-node/internal.d.ts
index 8748941c8a6f..8897747bd7c3 100644
--- a/packages/adapter-node/internal.d.ts
+++ b/packages/adapter-node/internal.d.ts
@@ -1,12 +1,3 @@
-declare module 'MANIFEST' {
-	import { SSRManifest } from '@sveltejs/kit';
-
-	export const base: string;
-	export const uncompressed_extensions: Set<string>;
-	export const manifest: SSRManifest;
-	export const prerendered: Set<string>;
-}
-
 declare module 'SERVER' {
-	export { Server } from '@sveltejs/kit';
+	export const server: import('@sveltejs/kit').Server;
 }
diff --git a/packages/adapter-node/src/handler.js b/packages/adapter-node/src/handler.js
index 28ab9d49b650..5aa8920b4402 100644
--- a/packages/adapter-node/src/handler.js
+++ b/packages/adapter-node/src/handler.js
@@ -6,17 +6,17 @@ import process from 'node:process';
 import sirv from 'sirv';
 import { parse as polka_url_parser } from '@polka/url';
 import { getRequest, setResponse, createReadableStream } from '@sveltejs/kit/node';
-import { Server } from 'SERVER';
-import { manifest, prerendered, base, uncompressed_extensions } from 'MANIFEST';
+import { server } from 'SERVER';
 import { dir } from './dir.js';
 import { env, env_prefix } from './env.js';
 import { parse_as_bytes } from './utils.js';
 
 /** @typedef {(req: IncomingMessage, res: ServerResponse, next: () => void | Promise<void>) => void | Promise<void>} Middleware */
 
-const server = new Server(manifest);
-
 const origin = ORIGIN;
+const uncompressed_extensions = UNCOMPRESSED_EXTENSIONS;
+const prerendered = PRERENDERED;
+const mime_types = MIME_TYPES;
 
 const xff_depth = parseInt(env('XFF_DEPTH', '1'));
 const address_header = env('ADDRESS_HEADER', '').toLowerCase();
@@ -32,7 +32,7 @@ if (isNaN(body_size_limit)) {
 	);
 }
 
-const asset_dir = `${dir}/client${base}`;
+const asset_dir = `${dir}/client${BASE_PATH}`;
 
 await server.init({
 	env: process.env,
@@ -56,16 +56,12 @@ function serve(path, client = false) {
 					}
 
 					// `sirv` uses its own bundled `mrmime`, which the manifest's added types never reach
-					let type = manifest.mimeTypes[pathname.slice(pathname.lastIndexOf('.'))];
+					let type = mime_types[pathname.slice(pathname.lastIndexOf('.'))];
 					if (type === 'text/html') type += ';charset=utf-8';
 					if (type) res.setHeader('content-type', type);
 
 					// only apply to build directory, not e.g. version.json
-					if (
-						client &&
-						pathname.startsWith(`/${manifest.appPath}/immutable/`) &&
-						res.statusCode === 200
-					) {
+					if (client && pathname.startsWith(`/${APP_PATH}/immutable/`) && res.statusCode === 200) {
 						res.setHeader('cache-control', 'public,max-age=31536000,immutable');
 					}
 				}
diff --git a/packages/adapter-vercel/files/serverless.js b/packages/adapter-vercel/files/serverless.js
index d6aa640edf16..8e3bdc096974 100644
--- a/packages/adapter-vercel/files/serverless.js
+++ b/packages/adapter-vercel/files/serverless.js
@@ -1,10 +1,7 @@
 import { createReadableStream } from '@sveltejs/kit/node';
-import { Server } from 'SERVER';
-import { manifest } from 'MANIFEST';
+import { server } from 'SERVER';
 import process from 'node:process';
 
-const server = new Server(manifest);
-
 await server.init({
 	env: process.env,
 	read: createReadableStream
diff --git a/packages/adapter-vercel/index.js b/packages/adapter-vercel/index.js
index 99a7b67c6ec5..daa085d3384c 100644
--- a/packages/adapter-vercel/index.js
+++ b/packages/adapter-vercel/index.js
@@ -61,11 +61,9 @@ const plugin = function (defaults = {}) {
 					builder.copy(proxy, entrypoint);
 				}
 
-				const relativePath = path.posix.relative(tmp, builder.getServerDirectory());
 				builder.copy(`${files}/serverless.js`, proxy ? `${tmp}/serverless.js` : entrypoint, {
 					replace: {
-						SERVER: `${relativePath}/index.js`,
-						MANIFEST: './manifest.js'
+						SERVER: `./server.js`
 					}
 				});
 				if (builder.hasServerInstrumentationFile()) {
@@ -74,11 +72,7 @@ const plugin = function (defaults = {}) {
 						instrumentation: `${builder.getServerDirectory()}/instrumentation.server.js`
 					});
 				}
-
-				write(
-					`${tmp}/manifest.js`,
-					`export const manifest = ${builder.generateManifest({ relativePath, routes })};\n`
-				);
+				builder.generateServerInstance(`${tmp}/server.js`, { routes });
 
 				await create_function_bundle(builder, entrypoint, dir, config);
 
diff --git a/packages/adapter-vercel/internal.d.ts b/packages/adapter-vercel/internal.d.ts
index 537f7cc041d1..8897747bd7c3 100644
--- a/packages/adapter-vercel/internal.d.ts
+++ b/packages/adapter-vercel/internal.d.ts
@@ -1,8 +1,3 @@
 declare module 'SERVER' {
-	export { Server } from '@sveltejs/kit';
-}
-
-declare module 'MANIFEST' {
-	import { SSRManifest } from '@sveltejs/kit';
-	export const manifest: SSRManifest;
+	export const server: import('@sveltejs/kit').Server;
 }
diff --git a/packages/kit/src/core/adapt/builder.js b/packages/kit/src/core/adapt/builder.js
index 5be5e91482bd..2a0790567988 100644
--- a/packages/kit/src/core/adapt/builder.js
+++ b/packages/kit/src/core/adapt/builder.js
@@ -13,19 +13,21 @@ import {
 	rmSync,
 	statSync
 } from 'node:fs';
-import { extname, resolve, join, dirname, relative } from 'node:path';
+import path from 'node:path';
 import { pipeline } from 'node:stream';
 import { promisify } from 'node:util';
 import zlib from 'node:zlib';
-import { copy, walk } from '../../utils/filesystem.js';
+import { copy, relative_path, walk } from '../../utils/filesystem.js';
 import { posixify } from '../../utils/os.js';
 import { generate_manifest } from '../generate_manifest/index.js';
 import { get_route_segments } from '../../utils/routing.js';
 import generate_fallback from '../postbuild/fallback.js';
-import { write } from '../sync/utils.js';
+import { dedent, write } from '../sync/utils.js';
 import { find_server_assets } from '../generate_manifest/find_server_assets.js';
 import { create_exported_declarations } from '../env.js';
 import { handle_issues, validate } from '../../exports/internal/env.js';
+import { get_mime_lookup } from '../utils.js';
+import { lookup as mime_lookup } from '../../utils/mime.js';
 
 const pipe = promisify(pipeline);
 const extensions = [
@@ -51,6 +53,7 @@ const extensions = [
  *   route_data: RouteData[];
  *   prerendered: Prerendered;
  *   prerender_map: PrerenderMap;
+ *   app_manifest: typeof import('$app/manifest');
  *   log: Logger;
  *   vite_config: ResolvedConfig;
  *   remotes: RemoteChunk[];
@@ -65,6 +68,7 @@ export function create_builder({
 	route_data,
 	prerendered,
 	prerender_map,
+	app_manifest,
 	log,
 	vite_config,
 	remotes,
@@ -103,6 +107,12 @@ export function create_builder({
 		return facade;
 	});
 
+	// $app/manifest cannot include the service worker because it's used by the service worker itself,
+	// but the adapter needs to know about it so we add it here.
+	if (build_data.service_worker) {
+		app_manifest.assets.push({ path: build_data.service_worker });
+	}
+
 	return {
 		log,
 		rimraf: (dir) => rmSync(dir, { force: true, recursive: true }),
@@ -112,17 +122,42 @@ export function create_builder({
 		config,
 		prerendered,
 		routes,
+		manifest: app_manifest,
+		get mimeTypes() {
+			// TODO - make the `generate_manifest` function return data instead of a string, and retrieve mime types from there
+			const mime_types = get_mime_lookup(build_data.manifest_data);
+			const server_assets = find_server_assets(
+				build_data,
+				route_data.filter((route) => prerender_map.get(route.id) !== true),
+				vite_config.root
+			);
+			/** @type {Record<string, number>} */
+			const files = {};
+			for (const file of server_assets) {
+				files[file] = statSync(path.resolve(build_data.out_dir, 'server', file)).size;
+
+				const ext = path.extname(file);
+				mime_types[ext] ??= mime_lookup(ext) || '';
+			}
+
+			// record extensions that only exist in prerendered output, e.g. a prerendered favicon.ico
+			for (const pathname of prerendered.paths) {
+				const ext = path.extname(pathname);
+				if (ext) mime_types[ext] ??= mime_lookup(ext) || '';
+			}
+			return mime_types;
+		},
 
 		async compress(directory) {
 			if (!existsSync(directory)) {
 				return [];
 			}
 
-			const files = [...walk(directory)].filter((file) => extensions.includes(extname(file)));
+			const files = [...walk(directory)].filter((file) => extensions.includes(path.extname(file)));
 
 			await Promise.all(
 				files.flatMap((file) => {
-					const abs = resolve(directory, file);
+					const abs = path.resolve(directory, file);
 					return [compress_file(abs, 'gz'), compress_file(abs, 'br')];
 				})
 			);
@@ -184,17 +219,34 @@ export function create_builder({
 			write(`${dest}/env.js`, `export const env=${payload}`);
 		},
 
-		generateManifest({ relativePath, routes: subset }) {
-			return generate_manifest({
-				build_data,
-				prerendered: prerendered.paths,
-				relative_path: relativePath,
-				routes: subset
-					? subset.map((route) => /** @type {import('types').RouteData} */ (lookup.get(route)))
-					: route_data.filter((route) => prerender_map.get(route.id) !== true),
-				remotes,
-				root: vite_config.root
-			});
+		generateManifest() {
+			throw new Error(
+				'The `generateManifest` adapter API has been removed — use `generateServerInstance` or `builder.manifest` instead. You may need to update your adapter'
+			);
+		},
+
+		generateServerInstance(dest, { routes: subset, serverDirectory } = {}) {
+			const relative = relative_path(
+				path.dirname(dest),
+				serverDirectory ?? this.getServerDirectory()
+			);
+			write(
+				dest,
+				dedent`
+					import { Server } from '${relative}/index.js';
+					const manifest = ${generate_manifest({
+						build_data,
+						prerendered: prerendered.paths,
+						relative_path: relative,
+						routes: subset
+							? subset.map((route) => /** @type {import('types').RouteData} */ (lookup.get(route)))
+							: route_data.filter((route) => prerender_map.get(route.id) !== true),
+						remotes,
+						root: vite_config.root
+					})};
+					export const server = new Server(manifest);
+				`
+			);
 		},
 
 		getBuildDirectory(name) {
@@ -241,7 +293,7 @@ export function create_builder({
 		instrument({
 			entrypoint,
 			instrumentation,
-			start = join(dirname(entrypoint), 'start.js'),
+			start = path.join(path.dirname(entrypoint), 'start.js'),
 			module = {
 				exports: ['default']
 			}
@@ -262,8 +314,10 @@ export function create_builder({
 				copy(`${entrypoint}.map`, `${start}.map`);
 			}
 
-			const relative_instrumentation = posixify(relative(dirname(entrypoint), instrumentation));
-			const relative_start = posixify(relative(dirname(entrypoint), start));
+			const relative_instrumentation = posixify(
+				path.relative(path.dirname(entrypoint), instrumentation)
+			);
+			const relative_start = posixify(path.relative(path.dirname(entrypoint), start));
 
 			const facade =
 				'generateText' in module
diff --git a/packages/kit/src/core/adapt/builder.spec.js b/packages/kit/src/core/adapt/builder.spec.js
index af76faba6d45..226e6436db42 100644
--- a/packages/kit/src/core/adapt/builder.spec.js
+++ b/packages/kit/src/core/adapt/builder.spec.js
@@ -54,8 +54,9 @@ test('copy files', () => {
 });
 
 test('compress files', async () => {
-	// @ts-expect-error - we don't need the whole config for this test
 	const builder = create_builder({
+		// @ts-expect-error - we don't need the whole config for this test
+		build_data: {},
 		route_data: []
 	});
 
@@ -77,8 +78,9 @@ test('compress files', async () => {
 });
 
 test('compress returns an empty array for a directory that does not exist', async () => {
-	// @ts-expect-error - we don't need the whole config for this test
 	const builder = create_builder({
+		// @ts-expect-error - we don't need the whole config for this test
+		build_data: {},
 		route_data: []
 	});
 
@@ -100,8 +102,11 @@ test('instrument generates facade with posix paths', () => {
 	const entrypoint = join(dest, 'index.js');
 	const instrumentation = join(dest, 'server', 'instrumentation.server.js');
 
-	// @ts-expect-error - we don't need the whole config for this test
-	const builder = create_builder({ route_data: [] });
+	const builder = create_builder({
+		// @ts-expect-error - we don't need the whole config for this test
+		build_data: {},
+		route_data: []
+	});
 
 	builder.instrument({
 		entrypoint,
diff --git a/packages/kit/src/core/adapt/index.js b/packages/kit/src/core/adapt/index.js
index 46f1fd5bc640..7b6c0850a26a 100644
--- a/packages/kit/src/core/adapt/index.js
+++ b/packages/kit/src/core/adapt/index.js
@@ -7,6 +7,7 @@ import { create_builder } from './builder.js';
  * @param {import('types').ServerMetadata} server_metadata
  * @param {import('types').Prerendered} prerendered
  * @param {import('types').PrerenderMap} prerender_map
+ * @param {typeof import('$app/manifest')} app_manifest
  * @param {import('types').Logger} log
  * @param {import('types').RemoteChunk[]} remotes
  * @param {import('vite').ResolvedConfig} vite_config
@@ -18,6 +19,7 @@ export async function adapt(
 	server_metadata,
 	prerendered,
 	prerender_map,
+	app_manifest,
 	log,
 	remotes,
 	vite_config,
@@ -48,6 +50,7 @@ export async function adapt(
 		route_data: build_data.manifest_data.routes.filter((route) => route.page || route.endpoint),
 		prerendered,
 		prerender_map,
+		app_manifest,
 		log,
 		remotes,
 		vite_config,
diff --git a/packages/kit/src/core/generate_manifest/index.js b/packages/kit/src/core/generate_manifest/index.js
index f524e1da70d2..9edced21991d 100644
--- a/packages/kit/src/core/generate_manifest/index.js
+++ b/packages/kit/src/core/generate_manifest/index.js
@@ -1,4 +1,4 @@
-/** @import { RemoteChunk } from 'types' */
+/** @import { BuildData, RemoteChunk, RouteData } from 'types' */
 import fs from 'node:fs';
 import path from 'node:path';
 import { lookup as mime_lookup } from '../../utils/mime.js';
@@ -15,10 +15,10 @@ import { uneval } from 'devalue';
  * Generates the data used to write the server-side manifest.js file. This data is used in the Vite
  * build process, to power routing, etc.
  * @param {{
- *   build_data: import('types').BuildData;
+ *   build_data: BuildData;
  *   prerendered: string[];
  *   relative_path: string;
- *   routes: import('types').RouteData[];
+ *   routes: RouteData[];
  *   remotes: RemoteChunk[];
  *   root: string;
  * }} opts
diff --git a/packages/kit/src/core/sync/write_app_manifest.js b/packages/kit/src/core/sync/write_app_manifest.js
index 8a0fe6b07b18..3a16fb5c2495 100644
--- a/packages/kit/src/core/sync/write_app_manifest.js
+++ b/packages/kit/src/core/sync/write_app_manifest.js
@@ -1,4 +1,5 @@
 /** @import { Asset, ManifestData, RouteData } from 'types' */
+/** @import { ManifestRoute } from '$app/manifest' */
 
 import { s } from '../../utils/misc.js';
 import { is_app_route, is_endpoint_route, is_page_route } from './create_manifest_data/index.js';
@@ -60,11 +61,11 @@ function stringify_assets(assets) {
 
 /**
  * @param {RouteData[] | undefined} routes
- * @returns {Array<{ id: string; page: boolean; endpoint: boolean }>}
+ * @returns {ManifestRoute[]}
  */
 export function get_manifest_routes(routes) {
 	return (
-		routes?.filter(is_app_route).map((route) => ({
+		routes?.filter(is_app_route).map((route) => /** @type {ManifestRoute} */ ({
 			id: route.id,
 			page: is_page_route(route),
 			endpoint: is_endpoint_route(route)
diff --git a/packages/kit/src/exports/public.d.ts b/packages/kit/src/exports/public.d.ts
index 8fde64196aeb..83070be7a60f 100644
--- a/packages/kit/src/exports/public.d.ts
+++ b/packages/kit/src/exports/public.d.ts
@@ -139,6 +139,17 @@ export interface Builder {
 	prerendered: Prerendered;
 	/** An array of all routes (including prerendered) */
 	routes: RouteDefinition[];
+	/**
+	 * The value of the `$app/manifest` module.
+	 * The only difference is `manifest.assets` also includes the service worker, if it exists.
+	 * @since 3.0.0
+	 */
+	manifest: typeof import('$app/manifest');
+	/**
+	 * A record of file extensions to MIME types
+	 * @since 3.0.0
+	 */
+	mimeTypes: Record<string, string>;
 
 	/**
 	 * Create separate functions that map to one or more routes of your app.
@@ -166,8 +177,9 @@ export interface Builder {
 	 * Generate a server-side manifest to initialise the SvelteKit [server](https://svelte.dev/docs/kit/@sveltejs-kit#Server) with.
 	 * @param opts
 	 * @param opts.relativePath A relative path to the base directory of the server build output
+	 * @deprecated removed in 3.0. Use `builder.generateServerInstance` or `builder.manifest` instead
 	 */
-	generateManifest: (opts: { relativePath: string; routes?: RouteDefinition[] }) => string;
+	generateManifest?: (opts: { relativePath: string; routes?: RouteDefinition[] }) => string;
 
 	/**
 	 * Resolve a path to the `name` directory inside `outDir`, e.g. `/path/to/.svelte-kit/my-adapter`.
@@ -181,6 +193,20 @@ export interface Builder {
 	/** Get the application path including any configured `base` path, e.g. `my-base-path/_app`. */
 	getAppPath: () => string;
 
+	/**
+	 * Generates a module exposing a SvelteKit [Server](https://svelte.dev/docs/kit/@sveltejs-kit#Server) instance.
+	 * @param dest
+	 * @param opts.routes A subset of the routes to include in the server's manifest
+	 * @param opts.serverDirectory The directory containing the server code. Defaults to `getServerDirectory()`.
+	 * @since 3.0.0
+	 */
+	generateServerInstance: (
+		dest: string,
+		opts?: {
+			routes?: RouteDefinition[];
+			serverDirectory?: string;
+		}
+	) => void;
 	/**
 	 * Write client assets to `dest`.
 	 * @param dest the destination folder
diff --git a/packages/kit/src/exports/vite/build/index.js b/packages/kit/src/exports/vite/build/index.js
index 84b850a50702..db7686ac2de7 100644
--- a/packages/kit/src/exports/vite/build/index.js
+++ b/packages/kit/src/exports/vite/build/index.js
@@ -862,6 +862,14 @@ export function plugin_compile(
 
 				// defer until after other buildApp hooks have run
 				finalise = async () => {
+					/** @type {typeof import('$app/manifest')} */
+					const app_manifest = {
+						assets: manifest_data.assets.map((asset) => ({ path: asset.file })),
+						immutable: immutable ?? [],
+						prerendered: prerendered_paths,
+						routes: get_manifest_routes(manifest_data.routes)
+					};
+
 					// defer creating the service worker to avoid other plugins from
 					// overwriting it if they run a client environment build
 					if (service_worker_entry_file) {
@@ -871,12 +879,10 @@ export function plugin_compile(
 						builder.environments.serviceWorker.config.define = {
 							...builder.environments.serviceWorker.config.define,
 
-							__SVELTEKIT_MANIFEST_ASSETS__: s(
-								manifest_data.assets.map((asset) => ({ path: asset.file }))
-							),
-							__SVELTEKIT_MANIFEST_IMMUTABLE__: s(immutable),
-							__SVELTEKIT_MANIFEST_PRERENDERED__: s(prerendered_paths),
-							__SVELTEKIT_MANIFEST_ROUTES__: s(get_manifest_routes(manifest_data.routes))
+							__SVELTEKIT_MANIFEST_ASSETS__: s(app_manifest.assets),
+							__SVELTEKIT_MANIFEST_IMMUTABLE__: s(app_manifest.immutable),
+							__SVELTEKIT_MANIFEST_PRERENDERED__: s(app_manifest.prerendered),
+							__SVELTEKIT_MANIFEST_ROUTES__: s(app_manifest.routes)
 						};
 
 						// we have to overwrite this because it can't be configured per environment in the config hook
@@ -905,6 +911,7 @@ export function plugin_compile(
 							metadata,
 							prerendered,
 							prerender_results.prerender_map,
+							app_manifest,
 							log,
 							remotes,
 							vite_config,
diff --git a/packages/kit/src/exports/vite/preview/index.js b/packages/kit/src/exports/vite/preview/index.js
index 2c29442c6032..4e0187c9e1b7 100644
--- a/packages/kit/src/exports/vite/preview/index.js
+++ b/packages/kit/src/exports/vite/preview/index.js
@@ -43,6 +43,7 @@ export async function preview(vite, svelte_config) {
 	/** @type {ServerModule} */
 	const { Server } = await import(pathToFileURL(join(dir, 'index.js')).href);
 
+	/** @type {{ manifest: import('@sveltejs/kit').SSRManifest }} */
 	const { manifest } = await import(pathToFileURL(join(dir, 'manifest.js')).href);
 
 	set_assets(assets);
diff --git a/packages/kit/types/index.d.ts b/packages/kit/types/index.d.ts
index 09c909a2a620..f060bdc20629 100644
--- a/packages/kit/types/index.d.ts
+++ b/packages/kit/types/index.d.ts
@@ -125,6 +125,17 @@ declare module '@sveltejs/kit' {
 		prerendered: Prerendered;
 		/** An array of all routes (including prerendered) */
 		routes: RouteDefinition[];
+		/**
+		 * The value of the `$app/manifest` module.
+		 * The only difference is `manifest.assets` also includes the service worker, if it exists.
+		 * @since 3.0.0
+		 */
+		manifest: typeof import('$app/manifest');
+		/**
+		 * A record of file extensions to MIME types
+		 * @since 3.0.0
+		 */
+		mimeTypes: Record<string, string>;
 
 		/**
 		 * Create separate functions that map to one or more routes of your app.
@@ -151,8 +162,9 @@ declare module '@sveltejs/kit' {
 		/**
 		 * Generate a server-side manifest to initialise the SvelteKit [server](https://svelte.dev/docs/kit/@sveltejs-kit#Server) with.
 		 * @param opts.relativePath A relative path to the base directory of the server build output
+		 * @deprecated removed in 3.0. Use `builder.generateServerInstance` or `builder.manifest` instead
 		 */
-		generateManifest: (opts: { relativePath: string; routes?: RouteDefinition[] }) => string;
+		generateManifest?: (opts: { relativePath: string; routes?: RouteDefinition[] }) => string;
 
 		/**
 		 * Resolve a path to the `name` directory inside `outDir`, e.g. `/path/to/.svelte-kit/my-adapter`.
@@ -166,6 +178,19 @@ declare module '@sveltejs/kit' {
 		/** Get the application path including any configured `base` path, e.g. `my-base-path/_app`. */
 		getAppPath: () => string;
 
+		/**
+		 * Generates a module exposing a SvelteKit [Server](https://svelte.dev/docs/kit/@sveltejs-kit#Server) instance.
+		 * @param opts.routes A subset of the routes to include in the server's manifest
+		 * @param opts.serverDirectory The directory containing the server code. Defaults to `getServerDirectory()`.
+		 * @since 3.0.0
+		 */
+		generateServerInstance: (
+			dest: string,
+			opts?: {
+				routes?: RouteDefinition[];
+				serverDirectory?: string;
+			}
+		) => void;
 		/**
 		 * Write client assets to `dest`.
 		 * @param dest the destination folder