diff --git a/runtime/index.d.ts b/runtime/index.d.ts
index b342e3cba..00ceb31eb 100644
--- a/runtime/index.d.ts
+++ b/runtime/index.d.ts
@@ -1,3 +1,10 @@
+/*
+ * This file declares all Sapper types that are accessible to project code.
+ * It is created in src/node_modules/@sapper in projects during the build.
+ * It must not import any internal Sapper types as it will not be possible for
+ * project code to reference those.
+ */
+
 declare module '@sapper/app' {
 	export interface Redirect {
 		statusCode: number
@@ -12,16 +19,64 @@ declare module '@sapper/app' {
 }
 
 declare module '@sapper/server' {
-	import { Handler, Req, Res } from '@sapper/internal/manifest-server';
+	import { IncomingMessage, ServerResponse } from 'http';
+	import { TLSSocket } from 'tls';
 
 	export type Ignore = string | RegExp | ((uri: string) => boolean) | Ignore[];
 
+	/**
+	 * The request object passed to middleware and server-side routes. 
+	 * These fields are common to both Polka and Express, but you are free to 
+	 * instead use the typings that come with the server you use.
+	 */
+	export interface SapperRequest extends IncomingMessage {
+		url: string;
+		method: string;	
+		baseUrl: string;
+	
+		/**
+		 * The originally requested URL, including parent router segments.
+		 */
+		originalUrl: string;
+	
+		/**
+		 * The path portion of the requested URL.
+		 */
+		path: string;
+	
+		/**
+		 * The values of named parameters within your route pattern
+		 */
+		params: Record<string, string>;
+	
+		/**
+		 * The un-parsed querystring
+		 */
+		search: string | null;
+	
+		/**
+		 * The parsed querystring
+		 */
+		query: Record<string, string>;
+
+		socket: TLSSocket;
+	}
+
+	export interface SapperResponse extends ServerResponse {
+		locals?: {
+			nonce?: string;
+			name?: string;
+		};
+	}
+		
 	export interface MiddlewareOptions {
-		session?: (req: Req, res: Res) => unknown
-		ignore?: Ignore
+		session?: (req: SapperRequest, res: SapperResponse) => unknown;
+		ignore?: Ignore;
 	}
 
-	export function middleware(opts: MiddlewareOptions): Handler;
+	export function middleware(
+		opts?: MiddlewareOptions
+	): (req: SapperRequest, res: SapperResponse, next: () => void) => void;
 }
 
 declare module '@sapper/service-worker' {
@@ -39,15 +94,26 @@ declare module '@sapper/common' {
 		redirect: (statusCode: number, location: string) => void;
 	}
 
-	export interface Page {
+	export type PageParams = Record<string, string>;
+	export type Query = Record<string, string | string[]>;
+	
+	export interface PageContext {
 		host: string;
 		path: string;
-		params: Record<string, string>;
-		query: Record<string, string | string[]>;
+		params: PageParams;
+		query: Query;
+		/** `error` is only set when the error page is being rendered. */
 		error?: Error;
 	}
 
+	/**
+	 * @deprecated PageContext is the preferred name. Page might be removed in the future.
+	 */
+	export { PageContext as Page };
+
+	export type PreloadResult = object | Promise<object>
+
 	export interface Preload {
-		(this: PreloadContext, page: Page, session: any): object | Promise<object>;
+		(this: PreloadContext, page: PageContext, session: any): PreloadResult;
 	}
 }
diff --git a/runtime/src/app/app.ts b/runtime/src/app/app.ts
index a85d14e68..44e7c183f 100644
--- a/runtime/src/app/app.ts
+++ b/runtime/src/app/app.ts
@@ -18,9 +18,9 @@ import {
 	Redirect,
 	Branch,
 	Page,
-	PageContext,
 	InitialData
 } from './types';
+import { PageContext } from '@sapper/common';
 import goto from './goto';
 import { page_store } from './stores';
 
diff --git a/runtime/src/app/router/index.ts b/runtime/src/app/router/index.ts
index 0ec240679..8eff0de8d 100644
--- a/runtime/src/app/router/index.ts
+++ b/runtime/src/app/router/index.ts
@@ -6,8 +6,8 @@ import {
 	ignore,
 	routes
 } from '@sapper/internal/manifest-client';
-import { Query } from '@sapper/internal/shared';
 import find_anchor from './find_anchor';
+import { Page, Query } from '@sapper/common';
 
 export let uid = 1;
 export function set_uid(n: number) {
@@ -68,7 +68,7 @@ export function init(base: string, handler: (dest: Target) => Promise<void>): vo
 }
 
 export function extract_query(search: string) {
-	const query = Object.create(null);
+	const query: Query = Object.create(null);
 	if (search.length > 0) {
 		search.slice(1).split('&').forEach(searchParam => {
 			const [, key, value = ''] = /([^=]*)(?:=(.*))?/.exec(decodeURIComponent(searchParam.replace(/\+/g, ' ')));
@@ -99,11 +99,11 @@ export function select_target(url: URL): Target {
 		const match = route.pattern.exec(path);
 
 		if (match) {
-			const query: Query = extract_query(url.search);
+			const query = extract_query(url.search);
 			const part = route.parts[route.parts.length - 1];
 			const params = part.params ? part.params(match) : {};
 
-			const page = { host: location.host, path, query, params };
+			const page: Page = { host: location.host, path, query, params };
 
 			return { href: url.href, route, match, page };
 		}
diff --git a/runtime/src/app/types.ts b/runtime/src/app/types.ts
index 0769708fd..1c97ea728 100644
--- a/runtime/src/app/types.ts
+++ b/runtime/src/app/types.ts
@@ -45,11 +45,3 @@ export interface Page {
 	params: Record<string, string>;
 	query: Record<string, string | string[]>;
 }
-
-/**
- * Information about the current page in the `page` store.
- */
-export interface PageContext extends Page {
-	/** `error` is only set when the error page is being rendered. */
-	error?: Error;
-}
diff --git a/runtime/src/common.ts b/runtime/src/common.ts
new file mode 100644
index 000000000..ae78a93ab
--- /dev/null
+++ b/runtime/src/common.ts
@@ -0,0 +1,6 @@
+/*
+ * This file exists to avoid errors on references to @sapper/common from inside Sapper.
+ * (@sapper/common is a namespace defined in index.d.ts)
+ */
+
+ export default null;
\ No newline at end of file
diff --git a/runtime/src/internal/manifest-client.d.ts b/runtime/src/internal/manifest-client.d.ts
index b33cc39a4..1b482decf 100644
--- a/runtime/src/internal/manifest-client.d.ts
+++ b/runtime/src/internal/manifest-client.d.ts
@@ -1,3 +1,4 @@
+import { PageParams } from '@sapper/common';
 import {
 	Preload
 } from './shared';
@@ -24,7 +25,7 @@ export interface Route {
 	pattern: RegExp;
 	parts: Array<{
 		i: number;
-		params?: (match: RegExpExecArray) => Record<string, string>;
+		params?: (match: RegExpExecArray) => PageParams;
 	}>;
 }
 
diff --git a/runtime/src/internal/manifest-server.d.ts b/runtime/src/internal/manifest-server.d.ts
index 3586ec7d1..fae257b8d 100644
--- a/runtime/src/internal/manifest-server.d.ts
+++ b/runtime/src/internal/manifest-server.d.ts
@@ -1,5 +1,3 @@
-import { ClientRequest, ServerResponse } from 'http';
-import { TLSSocket } from 'tls';
 import {
 	Preload
 } from './shared';
@@ -9,6 +7,8 @@ export const build_dir: string;
 export const dev: boolean;
 export const manifest: Manifest;
 
+export { SapperRequest, SapperResponse } from '@sapper/server';
+
 export interface SSRComponentModule {
 	default: SSRComponent;
 	preload?: Preload;
@@ -42,27 +42,7 @@ export interface ManifestPagePart {
 	params?: (match: RegExpMatchArray | null) => Record<string, string>;
 }
 
-export type Handler = (req: Req, res: Res, next: () => void) => void;
-
-export interface Req extends ClientRequest {
-	url: string;
-	baseUrl: string;
-	originalUrl: string;
-	method: string;
-	path: string;
-	params: Record<string, string>;
-	query: Record<string, string>;
-	headers: Record<string, string>;
-	socket: TLSSocket;
-}
-
-export interface Res extends ServerResponse {
-	write: (data: any) => boolean;
-	locals?: {
-		nonce?: string;
-		name?: string;
-	};
-}
+export type Handler = (req: SapperRequest, res: SapperResponse, next: () => void) => void;
 
 export interface ServerRoute {
 	pattern: RegExp;
diff --git a/runtime/src/internal/shared.d.ts b/runtime/src/internal/shared.d.ts
index d7b21f11f..511d6c91c 100644
--- a/runtime/src/internal/shared.d.ts
+++ b/runtime/src/internal/shared.d.ts
@@ -1,8 +1 @@
 export const CONTEXT_KEY: unknown;
-
-export type Params = Record<string, string>;
-export type Query = Record<string, string | string[]>;
-export type PreloadResult = object | Promise<object>;
-export interface Preload {
-  (this: PreloadContext, page: PreloadPage, session: any): PreloadResult;
-}
diff --git a/runtime/src/server/middleware/get_page_handler.ts b/runtime/src/server/middleware/get_page_handler.ts
index 09a0261cd..52ae7ad12 100644
--- a/runtime/src/server/middleware/get_page_handler.ts
+++ b/runtime/src/server/middleware/get_page_handler.ts
@@ -6,15 +6,22 @@ import devalue from 'devalue';
 import fetch from 'node-fetch';
 import URL from 'url';
 import { sourcemap_stacktrace } from './sourcemap_stacktrace';
-import { Manifest, ManifestPage, Req, Res, build_dir, dev, src_dir } from '@sapper/internal/manifest-server';
-import { PreloadResult } from '@sapper/internal/shared';
+import {
+    Manifest,
+    ManifestPage,
+    SapperRequest,
+    SapperResponse,
+    build_dir,
+    dev,
+    src_dir
+} from '@sapper/internal/manifest-server';
 import App from '@sapper/internal/App.svelte';
-import { PageContext } from '@sapper/app/types';
+import { PageContext, PreloadResult } from '@sapper/common';
 import detectClientOnlyReferences from './detect_client_only_references';
 
 export function get_page_handler(
 	manifest: Manifest,
-	session_getter: (req: Req, res: Res) => Promise<any>
+	session_getter: (req: SapperRequest, res: SapperResponse) => Promise<any>
 ) {
 	const get_build_info = dev
 		? () => JSON.parse(fs.readFileSync(path.join(build_dir, 'build.json'), 'utf-8'))
@@ -28,7 +35,7 @@ export function get_page_handler(
 
 	const { pages, error: error_route } = manifest;
 
-	function bail(res: Res, err: Error | string) {
+	function bail(res: SapperResponse, err: Error | string) {
 		console.error(err);
 
 		const message = dev ? escape_html(typeof err === 'string' ? err : err.message) : 'Internal server error';
@@ -37,7 +44,7 @@ export function get_page_handler(
 		res.end(`<pre>${message}</pre>`);
 	}
 
-	function handle_error(req: Req, res: Res, statusCode: number, error: Error | string) {
+	function handle_error(req: SapperRequest, res: SapperResponse, statusCode: number, error: Error | string) {
 		handle_page({
 			pattern: null,
 			parts: [
@@ -46,7 +53,12 @@ export function get_page_handler(
 		}, req, res, statusCode, error || 'Unknown error');
 	}
 
-	async function handle_page(page: ManifestPage, req: Req, res: Res, status = 200, error: Error | string = null) {
+	async function handle_page(
+        page: ManifestPage,
+        req: SapperRequest,
+        res: SapperResponse,
+        status = 200,
+        error: Error | string = null) {
 		const is_service_worker_index = req.path === '/service-worker-index.html';
 		const build_info: {
 			bundler: 'rollup' | 'webpack',
@@ -382,7 +394,7 @@ export function get_page_handler(
 		}
 	}
 
-	return function find_route(req: Req, res: Res, next: () => void) {
+	return function find_route(req: SapperRequest, res: SapperResponse, next: () => void) {
 		const req_path = req.path === '/service-worker-index.html' ? '/' : req.path;
 
 		const page = pages.find(p => p.pattern.test(req_path));
diff --git a/runtime/src/server/middleware/get_server_route_handler.ts b/runtime/src/server/middleware/get_server_route_handler.ts
index e3249c4fe..1aa30e64c 100644
--- a/runtime/src/server/middleware/get_server_route_handler.ts
+++ b/runtime/src/server/middleware/get_server_route_handler.ts
@@ -1,7 +1,7 @@
-import { Req, Res, ServerRoute } from '@sapper/internal/manifest-server';
+import { SapperRequest, SapperResponse, ServerRoute } from '@sapper/internal/manifest-server';
 
 export function get_server_route_handler(routes: ServerRoute[]) {
-	async function handle_route(route: ServerRoute, req: Req, res: Res, next: () => void) {
+	async function handle_route(route: ServerRoute, req: SapperRequest, res: SapperResponse, next: () => void) {
 		req.params = route.params(route.pattern.exec(req.path));
 
 		const method = req.method.toLowerCase();
@@ -63,7 +63,7 @@ export function get_server_route_handler(routes: ServerRoute[]) {
 		}
 	}
 
-	return function find_route(req: Req, res: Res, next: () => void) {
+	return function find_route(req: SapperRequest, res: SapperResponse, next: () => void) {
 		for (const route of routes) {
 			if (route.pattern.test(req.path)) {
 				handle_route(route, req, res, next);
diff --git a/runtime/src/server/middleware/index.ts b/runtime/src/server/middleware/index.ts
index f57239829..743d95c80 100644
--- a/runtime/src/server/middleware/index.ts
+++ b/runtime/src/server/middleware/index.ts
@@ -1,14 +1,14 @@
 import fs from 'fs';
 import path from 'path';
 import mime from 'mime/lite';
-import { Handler, Req, Res, build_dir, dev, manifest } from '@sapper/internal/manifest-server';
+import { Handler, SapperRequest, SapperResponse, build_dir, dev, manifest } from '@sapper/internal/manifest-server';
 import { get_server_route_handler } from './get_server_route_handler';
 import { get_page_handler } from './get_page_handler';
 
 type IgnoreValue = IgnoreValue[] | RegExp | ((uri: string) => boolean) | string;
 
 export default function middleware(opts: {
-	session?: (req: Req, res: Res) => any,
+	session?: (req: SapperRequest, res: SapperResponse) => any,
 	ignore?: IgnoreValue
 } = {}) {
 	const { session, ignore } = opts;
@@ -16,7 +16,7 @@ export default function middleware(opts: {
 	let emitted_basepath = false;
 
 	return compose_handlers(ignore, [
-		(req: Req, res: Res, next: () => void) => {
+		(req: SapperRequest, res: SapperResponse, next: () => void) => {
 			if (req.baseUrl === undefined) {
 				let originalUrl = req.originalUrl || req.url;
 				if (req.url === '/' && originalUrl[originalUrl.length - 1] !== '/') {
@@ -69,7 +69,7 @@ export default function middleware(opts: {
 export function compose_handlers(ignore: IgnoreValue, handlers: Handler[]): Handler {
 	const total = handlers.length;
 
-	function nth_handler(n: number, req: Req, res: Res, next: () => void) {
+	function nth_handler(n: number, req: SapperRequest, res: SapperResponse, next: () => void) {
 		if (n >= total) {
 			return next();
 		}
@@ -101,8 +101,8 @@ export function serve({ prefix, pathname, cache_control }: {
 	cache_control: string
 }) {
 	const filter = pathname
-		? (req: Req) => req.path === pathname
-		: (req: Req) => req.path.startsWith(prefix);
+		? (req: SapperRequest) => req.path === pathname
+		: (req: SapperRequest) => req.path.startsWith(prefix);
 
 	const cache: Map<string, Buffer> = new Map();
 
@@ -110,7 +110,7 @@ export function serve({ prefix, pathname, cache_control }: {
 		? (file: string) => fs.readFileSync(path.join(build_dir, file))
 		: (file: string) => (cache.has(file) ? cache : cache.set(file, fs.readFileSync(path.join(build_dir, file)))).get(file);
 
-	return (req: Req, res: Res, next: () => void) => {
+	return (req: SapperRequest, res: SapperResponse, next: () => void) => {
 		if (filter(req)) {
 			const type = mime.getType(req.path);
 
@@ -137,4 +137,4 @@ export function serve({ prefix, pathname, cache_control }: {
 	};
 }
 
-function noop() {}
+async function noop() {}
diff --git a/site/content/docs/02-routing.md b/site/content/docs/02-routing.md
index d9659ede4..cffccdc15 100644
--- a/site/content/docs/02-routing.md
+++ b/site/content/docs/02-routing.md
@@ -115,6 +115,15 @@ export async function get(req, res, next) {
 
 > `delete` is a reserved word in JavaScript. To handle DELETE requests, export a function called `del` instead.
 
+If you are using TypeScript, use the following types:
+
+```js
+import { SapperRequest, SapperResponse } from '@sapper/server';
+
+function get(req: SapperRequest, res: SapperResponse, next: () => void) { ... }
+```
+
+`SapperRequest` and `SapperResponse` will work with both Polka and Express. You can replace them with the types specific to your server, which are `polka.Request` / `http.ServerResponse` and `express.Request` / `express.Response`, respectively.
 
 ### File naming rules