diff --git a/.changeset/late-bobcats-brake.md b/.changeset/late-bobcats-brake.md
new file mode 100644
index 000000000000..3f151db82ea4
--- /dev/null
+++ b/.changeset/late-bobcats-brake.md
@@ -0,0 +1,10 @@
+---
+'@sveltejs/adapter-cloudflare': patch
+'@sveltejs/adapter-cloudflare-workers': patch
+'@sveltejs/adapter-netlify': patch
+'@sveltejs/adapter-node': patch
+'@sveltejs/adapter-vercel': patch
+'@sveltejs/kit': patch
+---
+
+[breaking] rename `app.render` to `server.respond`
diff --git a/packages/adapter-cloudflare-workers/files/entry.d.ts b/packages/adapter-cloudflare-workers/files/entry.d.ts
index 9a61c190ac9e..9df439aab626 100644
--- a/packages/adapter-cloudflare-workers/files/entry.d.ts
+++ b/packages/adapter-cloudflare-workers/files/entry.d.ts
@@ -1,5 +1,5 @@
-declare module 'APP' {
-	export { App } from '@sveltejs/kit';
+declare module 'SERVER' {
+	export { Server } from '@sveltejs/kit';
 }
 
 declare module 'MANIFEST' {
diff --git a/packages/adapter-cloudflare-workers/files/entry.js b/packages/adapter-cloudflare-workers/files/entry.js
index 2ce945ce377c..633e28eab676 100644
--- a/packages/adapter-cloudflare-workers/files/entry.js
+++ b/packages/adapter-cloudflare-workers/files/entry.js
@@ -1,8 +1,8 @@
-import { App } from 'APP';
+import { Server } from 'SERVER';
 import { manifest, prerendered } from 'MANIFEST';
 import { getAssetFromKV } from '@cloudflare/kv-asset-handler';
 
-const app = new App(manifest);
+const server = new Server(manifest);
 
 const prefix = `/${manifest.appDir}/`;
 
@@ -50,7 +50,7 @@ async function handle(event) {
 
 	// dynamically-generated pages
 	try {
-		return await app.render(request);
+		return await server.respond(request);
 	} catch (e) {
 		return new Response('Error rendering route:' + (e.message || e.toString()), { status: 500 });
 	}
diff --git a/packages/adapter-cloudflare-workers/index.js b/packages/adapter-cloudflare-workers/index.js
index e7e61a3735e3..745bbf006b11 100644
--- a/packages/adapter-cloudflare-workers/index.js
+++ b/packages/adapter-cloudflare-workers/index.js
@@ -40,7 +40,7 @@ export default function () {
 
 			builder.copy(`${files}/entry.js`, `${tmp}/entry.js`, {
 				replace: {
-					APP: `${relativePath}/app.js`,
+					SERVER: `${relativePath}/index.js`,
 					MANIFEST: './manifest.js'
 				}
 			});
diff --git a/packages/adapter-cloudflare/files/worker.d.ts b/packages/adapter-cloudflare/files/worker.d.ts
index ea54b4bd2e83..3689c3f5e51e 100644
--- a/packages/adapter-cloudflare/files/worker.d.ts
+++ b/packages/adapter-cloudflare/files/worker.d.ts
@@ -1,5 +1,5 @@
-declare module 'APP' {
-	export { App } from '@sveltejs/kit';
+declare module 'SERVER' {
+	export { Server } from '@sveltejs/kit';
 }
 
 declare module 'MANIFEST' {
diff --git a/packages/adapter-cloudflare/files/worker.js b/packages/adapter-cloudflare/files/worker.js
index fd256f13b1dd..d41d6c27c269 100644
--- a/packages/adapter-cloudflare/files/worker.js
+++ b/packages/adapter-cloudflare/files/worker.js
@@ -1,7 +1,7 @@
-import { App } from 'APP';
+import { Server } from 'SERVER';
 import { manifest, prerendered } from 'MANIFEST';
 
-const app = new App(manifest);
+const server = new Server(manifest);
 
 const prefix = `/${manifest.appDir}/`;
 
@@ -50,7 +50,7 @@ export default {
 
 		// dynamically-generated pages
 		try {
-			return await app.render(req, { platform: { env, context } });
+			return await server.respond(req, { platform: { env, context } });
 		} catch (e) {
 			return new Response('Error rendering route: ' + (e.message || e.toString()), { status: 500 });
 		}
diff --git a/packages/adapter-cloudflare/index.js b/packages/adapter-cloudflare/index.js
index a44a55697d9d..9af0566f94ce 100644
--- a/packages/adapter-cloudflare/index.js
+++ b/packages/adapter-cloudflare/index.js
@@ -32,7 +32,7 @@ export default function (options = {}) {
 
 			builder.copy(`${files}/worker.js`, `${tmp}/_worker.js`, {
 				replace: {
-					APP: `${relativePath}/app.js`,
+					SERVER: `${relativePath}/index.js`,
 					MANIFEST: './manifest.js'
 				}
 			});
diff --git a/packages/adapter-netlify/index.js b/packages/adapter-netlify/index.js
index 3ebb45324d03..a37894a88c75 100644
--- a/packages/adapter-netlify/index.js
+++ b/packages/adapter-netlify/index.js
@@ -51,7 +51,7 @@ export default function ({ split = false } = {}) {
 			const redirects = [];
 
 			const replace = {
-				'0APP': './server/app.js' // digit prefix prevents CJS build from using this as a variable name, which would also get replaced
+				'0SERVER': './server/index.js' // digit prefix prevents CJS build from using this as a variable name, which would also get replaced
 			};
 
 			if (esm) {
diff --git a/packages/adapter-netlify/src/handler.d.ts b/packages/adapter-netlify/src/handler.d.ts
index 75ea691df713..2501e38bf35a 100644
--- a/packages/adapter-netlify/src/handler.d.ts
+++ b/packages/adapter-netlify/src/handler.d.ts
@@ -1,3 +1,3 @@
-declare module '0APP' {
-	export { App } from '@sveltejs/kit';
+declare module '0SERVER' {
+	export { Server } from '@sveltejs/kit';
 }
diff --git a/packages/adapter-netlify/src/handler.js b/packages/adapter-netlify/src/handler.js
index e23c8f96d17b..fcf928145ccf 100644
--- a/packages/adapter-netlify/src/handler.js
+++ b/packages/adapter-netlify/src/handler.js
@@ -1,15 +1,15 @@
 import './shims';
-import { App } from '0APP';
+import { Server } from '0SERVER';
 
 /**
  * @param {import('@sveltejs/kit').SSRManifest} manifest
  * @returns {import('@netlify/functions').Handler}
  */
 export function init(manifest) {
-	const app = new App(manifest);
+	const server = new Server(manifest);
 
 	return async (event) => {
-		const rendered = await app.render(to_request(event));
+		const rendered = await server.respond(to_request(event));
 
 		const partial_response = {
 			statusCode: rendered.status,
diff --git a/packages/adapter-node/index.js b/packages/adapter-node/index.js
index 70898ffcd033..8fd7059511d8 100644
--- a/packages/adapter-node/index.js
+++ b/packages/adapter-node/index.js
@@ -49,7 +49,7 @@ export default function ({
 
 			builder.copy(files, out, {
 				replace: {
-					APP: './server/app.js',
+					SERVER: './server/index.js',
 					MANIFEST: './manifest.js',
 					PATH_ENV: JSON.stringify(path_env),
 					HOST_ENV: JSON.stringify(host_env),
diff --git a/packages/adapter-node/rollup.config.js b/packages/adapter-node/rollup.config.js
index 21da6b8acaa4..9bd5c9970fab 100644
--- a/packages/adapter-node/rollup.config.js
+++ b/packages/adapter-node/rollup.config.js
@@ -14,6 +14,6 @@ export default [
 			format: 'esm'
 		},
 		plugins: [nodeResolve(), commonjs(), json()],
-		external: ['APP', 'MANIFEST', ...require('module').builtinModules]
+		external: ['SERVER', 'MANIFEST', ...require('module').builtinModules]
 	}
 ];
diff --git a/packages/adapter-node/src/ambient.d.ts b/packages/adapter-node/src/ambient.d.ts
index 42c4f9f12309..537f7cc041d1 100644
--- a/packages/adapter-node/src/ambient.d.ts
+++ b/packages/adapter-node/src/ambient.d.ts
@@ -1,5 +1,5 @@
-declare module 'APP' {
-	export { App } from '@sveltejs/kit';
+declare module 'SERVER' {
+	export { Server } from '@sveltejs/kit';
 }
 
 declare module 'MANIFEST' {
diff --git a/packages/adapter-node/src/handler.js b/packages/adapter-node/src/handler.js
index 3357a9e2120d..f3b9662dddd9 100644
--- a/packages/adapter-node/src/handler.js
+++ b/packages/adapter-node/src/handler.js
@@ -4,12 +4,12 @@ import path from 'path';
 import sirv from 'sirv';
 import { fileURLToPath } from 'url';
 import { getRequest, setResponse } from '@sveltejs/kit/node';
-import { App } from 'APP';
+import { Server } from 'SERVER';
 import { manifest } from 'MANIFEST';
 
 /* global ORIGIN, PROTOCOL_HEADER, HOST_HEADER */
 
-const app = new App(manifest);
+const server = new Server(manifest);
 const origin = ORIGIN;
 const protocol_header = PROTOCOL_HEADER && process.env[PROTOCOL_HEADER];
 const host_header = (HOST_HEADER && process.env[HOST_HEADER]) || 'host';
@@ -45,7 +45,7 @@ const ssr = async (req, res) => {
 		return res.end(err.reason || 'Invalid request body');
 	}
 
-	setResponse(res, await app.render(request));
+	setResponse(res, await server.respond(request));
 };
 
 /** @param {import('polka').Middleware[]} handlers */
diff --git a/packages/adapter-vercel/files/ambient.d.ts b/packages/adapter-vercel/files/ambient.d.ts
index 42c4f9f12309..537f7cc041d1 100644
--- a/packages/adapter-vercel/files/ambient.d.ts
+++ b/packages/adapter-vercel/files/ambient.d.ts
@@ -1,5 +1,5 @@
-declare module 'APP' {
-	export { App } from '@sveltejs/kit';
+declare module 'SERVER' {
+	export { Server } from '@sveltejs/kit';
 }
 
 declare module 'MANIFEST' {
diff --git a/packages/adapter-vercel/files/entry.js b/packages/adapter-vercel/files/entry.js
index 9b42dbc79320..56f409c1a6fa 100644
--- a/packages/adapter-vercel/files/entry.js
+++ b/packages/adapter-vercel/files/entry.js
@@ -1,9 +1,9 @@
 import './shims';
 import { getRequest, setResponse } from '@sveltejs/kit/node';
-import { App } from 'APP';
+import { Server } from 'SERVER';
 import { manifest } from 'MANIFEST';
 
-const app = new App(manifest);
+const server = new Server(manifest);
 
 /**
  * @param {import('http').IncomingMessage} req
@@ -19,5 +19,5 @@ export default async (req, res) => {
 		return res.end(err.reason || 'Invalid request body');
 	}
 
-	setResponse(res, await app.render(request));
+	setResponse(res, await server.respond(request));
 };
diff --git a/packages/adapter-vercel/index.js b/packages/adapter-vercel/index.js
index 7ed2a5c72186..d9c69de89d2e 100644
--- a/packages/adapter-vercel/index.js
+++ b/packages/adapter-vercel/index.js
@@ -112,7 +112,7 @@ export default function ({ external = [] } = {}) {
 
 			builder.copy(files, tmp, {
 				replace: {
-					APP: `${relativePath}/app.js`,
+					SERVER: `${relativePath}/index.js`,
 					MANIFEST: './manifest.js'
 				}
 			});
diff --git a/packages/kit/src/core/adapt/fixtures/basic/.svelte-kit/output/server/app.js b/packages/kit/src/core/adapt/fixtures/basic/.svelte-kit/output/server/index.js
similarity index 100%
rename from packages/kit/src/core/adapt/fixtures/basic/.svelte-kit/output/server/app.js
rename to packages/kit/src/core/adapt/fixtures/basic/.svelte-kit/output/server/index.js
diff --git a/packages/kit/src/core/adapt/prerender/prerender.js b/packages/kit/src/core/adapt/prerender/prerender.js
index e65e6fd6f95a..b950afeda76b 100644
--- a/packages/kit/src/core/adapt/prerender/prerender.js
+++ b/packages/kit/src/core/adapt/prerender/prerender.js
@@ -67,8 +67,8 @@ export async function prerender({ cwd, out, log, config, build_data, fallback, a
 
 	const server_root = resolve_path(cwd, `${SVELTE_KIT}/output`);
 
-	/** @type {import('types').AppModule} */
-	const { App, override } = await import(pathToFileURL(`${server_root}/server/app.js`).href);
+	/** @type {import('types').ServerModule} */
+	const { Server, override } = await import(pathToFileURL(`${server_root}/server/index.js`).href);
 	const { manifest } = await import(pathToFileURL(`${server_root}/server/manifest.js`).href);
 
 	override({
@@ -77,7 +77,7 @@ export async function prerender({ cwd, out, log, config, build_data, fallback, a
 		read: (file) => readFileSync(join(config.kit.files.assets, file))
 	});
 
-	const app = new App(manifest);
+	const server = new Server(manifest);
 
 	const error = normalise_error_handler(log, config.kit.prerender.onError);
 
@@ -145,7 +145,7 @@ export async function prerender({ cwd, out, log, config, build_data, fallback, a
 		/** @type {Map<string, import('types').PrerenderDependency>} */
 		const dependencies = new Map();
 
-		const response = await app.render(new Request(`http://sveltekit-prerender${encoded}`), {
+		const response = await server.respond(new Request(`http://sveltekit-prerender${encoded}`), {
 			prerender: {
 				all,
 				dependencies
@@ -282,7 +282,7 @@ export async function prerender({ cwd, out, log, config, build_data, fallback, a
 	}
 
 	if (fallback) {
-		const rendered = await app.render(new Request('http://sveltekit-prerender/[fallback]'), {
+		const rendered = await server.respond(new Request('http://sveltekit-prerender/[fallback]'), {
 			prerender: {
 				fallback,
 				all: false,
diff --git a/packages/kit/src/core/build/build_server.js b/packages/kit/src/core/build/build_server.js
index c9e3dc1cd085..dfc2cce9acf1 100644
--- a/packages/kit/src/core/build/build_server.js
+++ b/packages/kit/src/core/build/build_server.js
@@ -18,7 +18,7 @@ import { s } from '../../utils/misc.js';
  * }} opts
  * @returns
  */
-const app_template = ({ config, hooks, has_service_worker, template }) => `
+const server_template = ({ config, hooks, has_service_worker, template }) => `
 import root from '__GENERATED__/root.svelte';
 import { respond } from '${runtime}/server/index.js';
 import { set_paths, assets, base } from '${runtime}/paths.js';
@@ -55,7 +55,7 @@ export function override(settings) {
 	read = settings.read;
 }
 
-export class App {
+export class Server {
 	constructor(manifest) {
 		const hooks = get_hooks(user_hooks);
 
@@ -95,7 +95,7 @@ export class App {
 		};
 	}
 
-	render(request, options = {}) {
+	respond(request, options = {}) {
 		if (!(request instanceof Request)) {
 			throw new Error('The first argument to app.render must be a Request object. See https://github.com/sveltejs/kit/pull/3384 for details');
 		}
@@ -139,7 +139,7 @@ export async function build_server(
 
 	/** @type {Record<string, string>} */
 	const input = {
-		app: `${build_dir}/app.js`
+		index: `${build_dir}/index.js`
 	};
 
 	// add entry points for every endpoint...
@@ -172,8 +172,8 @@ export async function build_server(
 	};
 
 	fs.writeFileSync(
-		input.app,
-		app_template({
+		input.index,
+		server_template({
 			config,
 			hooks: app_relative(hooks_file),
 			has_service_worker: service_worker_register && !!service_worker_entry_file,
diff --git a/packages/kit/src/core/preview/index.js b/packages/kit/src/core/preview/index.js
index 60e1e000b7d4..577775919e8a 100644
--- a/packages/kit/src/core/preview/index.js
+++ b/packages/kit/src/core/preview/index.js
@@ -33,11 +33,11 @@ export async function preview({
 }) {
 	__fetch_polyfill();
 
-	const app_file = resolve(cwd, `${SVELTE_KIT}/output/server/app.js`);
+	const index_file = resolve(cwd, `${SVELTE_KIT}/output/server/index.js`);
 	const manifest_file = resolve(cwd, `${SVELTE_KIT}/output/server/manifest.js`);
 
-	/** @type {import('types').AppModule} */
-	const { App, override } = await import(pathToFileURL(app_file).href);
+	/** @type {import('types').ServerModule} */
+	const { Server, override } = await import(pathToFileURL(index_file).href);
 
 	const { manifest } = await import(pathToFileURL(manifest_file).href);
 
@@ -66,12 +66,12 @@ export async function preview({
 		read: (file) => fs.readFileSync(join(config.kit.files.assets, file))
 	});
 
-	const app = new App(manifest);
+	const server = new Server(manifest);
 
 	/** @type {import('vite').UserConfig} */
 	const vite_config = (config.kit.vite && (await config.kit.vite())) || {};
 
-	const server = await get_server(use_https, vite_config, (req, res) => {
+	const http_server = await get_server(use_https, vite_config, (req, res) => {
 		if (req.url == null) {
 			throw new Error('Invalid request url');
 		}
@@ -93,7 +93,7 @@ export async function preview({
 					return res.end(err.reason || 'Invalid request body');
 				}
 
-				setResponse(res, await app.render(request));
+				setResponse(res, await server.respond(request));
 			} else {
 				res.statusCode = 404;
 				res.end('Not found');
@@ -120,9 +120,9 @@ export async function preview({
 		}
 	});
 
-	await server.listen(port, host || '0.0.0.0');
+	await http_server.listen(port, host || '0.0.0.0');
 
-	return Promise.resolve(server);
+	return Promise.resolve(http_server);
 }
 
 /**
diff --git a/packages/kit/types/index.d.ts b/packages/kit/types/index.d.ts
index a0031a8da805..51383029a9b4 100644
--- a/packages/kit/types/index.d.ts
+++ b/packages/kit/types/index.d.ts
@@ -20,11 +20,6 @@ import {
 } from './internal';
 import './ambient';
 
-export class App {
-	constructor(manifest: SSRManifest);
-	render(request: Request, options?: RequestOptions): Promise<Response>;
-}
-
 export interface Adapter {
 	name: string;
 	adapt(builder: Builder): Promise<void>;
@@ -371,6 +366,11 @@ export interface RequestOptions {
 
 export type ResolveOptions = Partial<RequiredResolveOptions>;
 
+export class Server {
+	constructor(manifest: SSRManifest);
+	respond(request: Request, options?: RequestOptions): Promise<Response>;
+}
+
 export interface SSRManifest {
 	appDir: string;
 	assets: Set<string>;
diff --git a/packages/kit/types/internal.d.ts b/packages/kit/types/internal.d.ts
index 76cb3a2dccc2..cf409dbb141a 100644
--- a/packages/kit/types/internal.d.ts
+++ b/packages/kit/types/internal.d.ts
@@ -9,9 +9,9 @@ import {
 	Handle,
 	HandleError,
 	RequestEvent,
-	App,
 	RequestOptions,
-	PrerenderErrorHandler
+	PrerenderErrorHandler,
+	Server
 } from './index';
 
 export interface AdapterEntry {
@@ -38,8 +38,8 @@ export interface AdapterEntry {
 	}) => void;
 }
 
-export interface AppModule {
-	App: typeof InternalApp;
+export interface ServerModule {
+	Server: typeof InternalServer;
 
 	override(options: {
 		paths: {
@@ -117,8 +117,8 @@ export interface Hooks {
 
 export type HttpMethod = 'get' | 'head' | 'post' | 'put' | 'delete' | 'patch';
 
-export class InternalApp extends App {
-	render(
+export class InternalServer extends Server {
+	respond(
 		request: Request,
 		options?: RequestOptions & {
 			prerender?: PrerenderOptions;