diff --git a/index.d.ts b/index.d.ts
index d87a09e..519e395 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -44,21 +44,30 @@ export declare interface App {
   [namespace: string]: Package;
 }
 
-export declare type Middleware = (
-  req: Request,
-  res: Response,
+export declare type Middleware<
+  TRequest extends Request = Request,
+  TResponse extends Response = Response
+> = (
+  req: TRequest,
+  res: TResponse,
   next: NextFunction
 ) => void;
-export declare type ErrorHandlingMiddleware = (
+export declare type ErrorHandlingMiddleware<
+  TRequest extends Request = Request,
+  TResponse extends Response = Response
+> = (
   error: Error,
-  req: Request,
-  res: Response,
+  req: TRequest,
+  res: TResponse,
   next: NextFunction
 ) => void;
 export declare type ErrorCallback = (error?: Error) => void;
-export declare type HandlerFunction = (
-  req: Request,
-  res: Response,
+export declare type HandlerFunction<
+  TRequest extends Request = Request,
+  TResponse extends Response = Response
+> = (
+  req: TRequest,
+  res: TResponse,
   next?: NextFunction
 ) => void | any | Promise<any>;
 
@@ -196,7 +205,7 @@ export declare class Request {
   [key: string]: any;
 }
 
-export declare class Response {
+export declare class Response<TBody = any> {
   status(code: number): this;
 
   sendStatus(code: number): void;
@@ -219,11 +228,11 @@ export declare class Response {
     callback?: ErrorCallback
   ): Promise<string>;
 
-  send(body: any): void;
+  send(body: TBody): void;
 
-  json(body: any): void;
+  json(body: TBody): void;
 
-  jsonp(body: any): void;
+  jsonp(body: TBody): void;
 
   html(body: any): void;
 
@@ -269,62 +278,157 @@ export declare class API {
   app(namespace: string, package: Package): App;
   app(packages: App): App;
 
-  get(
+  get<TRequest extends Request = Request, TResponse extends Response = Response>(
     path: string,
-    ...middlewaresAndHandler: (Middleware | HandlerFunction)[]
+    ...middlewaresAndHandler: (
+      | Middleware<TRequest, TResponse>
+      | HandlerFunction<TRequest, TResponse>
+    )[]
+  ): void;
+  get<TRequest extends Request = Request, TResponse extends Response = Response>(
+    ...middlewaresAndHandler: (
+      | Middleware<TRequest, TResponse>
+      | HandlerFunction<TRequest, TResponse>
+    )[]
   ): void;
-  get(...middlewaresAndHandler: (Middleware | HandlerFunction)[]): void;
 
-  post(
+  post<
+    TRequest extends Request = Request,
+    TResponse extends Response = Response
+  >(
     path: string,
-    ...middlewaresAndHandler: (Middleware | HandlerFunction)[]
+    ...middlewaresAndHandler: (
+      | Middleware<TRequest, TResponse>
+      | HandlerFunction<TRequest, TResponse>
+    )[]
+  ): void;
+  post<
+    TRequest extends Request = Request,
+    TResponse extends Response = Response
+  >(
+    ...middlewaresAndHandler: (
+      | Middleware<TRequest, TResponse>
+      | HandlerFunction<TRequest, TResponse>
+    )[]
   ): void;
-  post(...middlewaresAndHandler: (Middleware | HandlerFunction)[]): void;
 
-  put(
+  put<TRequest extends Request = Request, TResponse extends Response = Response>(
     path: string,
-    ...middlewaresAndHandler: (Middleware | HandlerFunction)[]
+    ...middlewaresAndHandler: (
+      | Middleware<TRequest, TResponse>
+      | HandlerFunction<TRequest, TResponse>
+    )[]
+  ): void;
+  put<TRequest extends Request = Request, TResponse extends Response = Response>(
+    ...middlewaresAndHandler: (
+      | Middleware<TRequest, TResponse>
+      | HandlerFunction<TRequest, TResponse>
+    )[]
   ): void;
-  put(...middlewaresAndHandler: (Middleware | HandlerFunction)[]): void;
 
-  patch(
+  patch<
+    TRequest extends Request = Request,
+    TResponse extends Response = Response
+  >(
     path: string,
-    ...middlewaresAndHandler: (Middleware | HandlerFunction)[]
+    ...middlewaresAndHandler: (
+      | Middleware<TRequest, TResponse>
+      | HandlerFunction<TRequest, TResponse>
+    )[]
+  ): void;
+  patch<
+    TRequest extends Request = Request,
+    TResponse extends Response = Response
+  >(
+    ...middlewaresAndHandler: (
+      | Middleware<TRequest, TResponse>
+      | HandlerFunction<TRequest, TResponse>
+    )[]
   ): void;
-  patch(...middlewaresAndHandler: (Middleware | HandlerFunction)[]): void;
 
-  delete(
+  delete<
+    TRequest extends Request = Request,
+    TResponse extends Response = Response
+  >(
     path: string,
-    ...middlewaresAndHandler: (Middleware | HandlerFunction)[]
+    ...middlewaresAndHandler: (
+      | Middleware<TRequest, TResponse>
+      | HandlerFunction<TRequest, TResponse>
+    )[]
   ): void;
-  delete(...middlewaresAndHandler: HandlerFunction[]): void;
-
-  options(
+  delete<
+    TRequest extends Request = Request,
+    TResponse extends Response = Response
+  >(...middlewaresAndHandler: HandlerFunction<TRequest, TResponse>[]): void;
+
+  options<
+    TRequest extends Request = Request,
+    TResponse extends Response = Response
+  >(
     path: string,
-    ...middlewaresAndHandler: (Middleware | HandlerFunction)[]
+    ...middlewaresAndHandler: (
+      | Middleware<TRequest, TResponse>
+      | HandlerFunction<TRequest, TResponse>
+    )[]
+  ): void;
+  options<
+    TRequest extends Request = Request,
+    TResponse extends Response = Response
+  >(
+    ...middlewaresAndHandler: (
+      | Middleware<TRequest, TResponse>
+      | HandlerFunction<TRequest, TResponse>
+    )[]
   ): void;
-  options(...middlewaresAndHandler: (Middleware | HandlerFunction)[]): void;
 
-  head(
+  head<TRequest extends Request = Request, TResponse extends Response = Response>(
     path: string,
-    ...middlewaresAndHandler: (Middleware | HandlerFunction)[]
+    ...middlewaresAndHandler: (
+      | Middleware<TRequest, TResponse>
+      | HandlerFunction<TRequest, TResponse>
+    )[]
+  ): void;
+  head<TRequest extends Request = Request, TResponse extends Response = Response>(
+    ...middlewaresAndHandler: (
+      | Middleware<TRequest, TResponse>
+      | HandlerFunction<TRequest, TResponse>
+    )[]
   ): void;
-  head(...middlewaresAndHandler: (Middleware | HandlerFunction)[]): void;
 
-  any(
+  any<TRequest extends Request = Request, TResponse extends Response = Response>(
     path: string,
-    ...middlewaresAndHandler: (Middleware | HandlerFunction)[]
+    ...middlewaresAndHandler: (
+      | Middleware<TRequest, TResponse>
+      | HandlerFunction<TRequest, TResponse>
+    )[]
+  ): void;
+  any<TRequest extends Request = Request, TResponse extends Response = Response>(
+    ...middlewaresAndHandler: (
+      | Middleware<TRequest, TResponse>
+      | HandlerFunction<TRequest, TResponse>
+    )[]
   ): void;
-  any(...middlewaresAndHandler: (Middleware | HandlerFunction)[]): void;
 
-  METHOD(
+  METHOD<
+    TRequest extends Request = Request,
+    TResponse extends Response = Response
+  >(
     method: METHODS | METHODS[],
     path: string,
-    ...middlewaresAndHandler: (Middleware | HandlerFunction)[]
+    ...middlewaresAndHandler: (
+      | Middleware<TRequest, TResponse>
+      | HandlerFunction<TRequest, TResponse>
+    )[]
   ): void;
-  METHOD(
+  METHOD<
+    TRequest extends Request = Request,
+    TResponse extends Response = Response
+  >(
     method: METHODS | METHODS[],
-    ...middlewaresAndHandler: (Middleware | HandlerFunction)[]
+    ...middlewaresAndHandler: (
+      | Middleware<TRequest, TResponse>
+      | HandlerFunction<TRequest, TResponse>
+    )[]
   ): void;
 
   register(
@@ -336,9 +440,20 @@ export declare class API {
   routes(format: false): string[][];
   routes(): string[][];
 
-  use(path: string, ...middleware: Middleware[]): void;
-  use(paths: string[], ...middleware: Middleware[]): void;
-  use(...middleware: (Middleware | ErrorHandlingMiddleware)[]): void;
+  use<TRequest extends Request = Request, TResponse extends Response = Response>(
+    path: string,
+    ...middleware: Middleware<TRequest, TResponse>[]
+  ): void;
+  use<TRequest extends Request = Request, TResponse extends Response = Response>(
+    paths: string[],
+    ...middleware: Middleware<TRequest, TResponse>[]
+  ): void;
+  use<TRequest extends Request = Request, TResponse extends Response = Response>(
+    ...middleware: (
+      | Middleware<TRequest, TResponse>
+      | ErrorHandlingMiddleware<TRequest, TResponse>
+    )[]
+  ): void;
 
   finally(callback: FinallyFunction): void;
 
diff --git a/index.test-d.ts b/index.test-d.ts
index e4b68bd..cd30bf6 100644
--- a/index.test-d.ts
+++ b/index.test-d.ts
@@ -26,6 +26,23 @@ import {
   ALBEvent,
 } from 'aws-lambda';
 
+type MetricsLogger = {
+  setProperty(name: string, value: boolean): void;
+};
+
+interface TypedRequest extends Request {
+  params: {
+    thingId: string;
+    anotherThingId: string;
+  };
+  context: Context & { metrics: MetricsLogger };
+}
+
+interface TypedResponseBody {
+  hello: string;
+  foo: string;
+}
+
 const options: Options = {
   base: '/api',
   version: 'v1',
@@ -174,6 +191,10 @@ expectType<void>(
 
 expectType<void>(res.redirect('/new-path'));
 
+const typedRes = {} as Response<TypedResponseBody>;
+expectType<void>(typedRes.json({ hello: 'thing', foo: 'another-thing' }));
+expectError(typedRes.json({ hello: 'thing' }));
+
 const middleware: Middleware = (req, res, next) => {
   next();
 };
@@ -189,6 +210,37 @@ const handler: HandlerFunction = (req, res) => {
 };
 expectType<HandlerFunction>(handler);
 
+const typedHandler: HandlerFunction<TypedRequest, Response<TypedResponseBody>> = (
+  req,
+  res
+) => {
+  const { metrics } = req.context;
+  metrics.setProperty('test', true);
+  res.json({
+    hello: req.params.thingId,
+    foo: req.params.anotherThingId,
+  });
+};
+expectType<HandlerFunction<TypedRequest, Response<TypedResponseBody>>>(
+  typedHandler
+);
+
+api.get<TypedRequest, Response<TypedResponseBody>>('/typed', typedHandler);
+const invalidTypedHandler: HandlerFunction<
+  TypedRequest,
+  Response<TypedResponseBody>
+> = (req, res) => {
+  expectError(
+    res.json({
+      hello: req.params.thingId,
+    })
+  );
+};
+api.get<TypedRequest, Response<TypedResponseBody>>(
+  '/typed-invalid',
+  invalidTypedHandler
+);
+
 const cookieOptions: CookieOptions = {
   domain: 'example.com',
   httpOnly: true,