diff --git a/CHANGELOG.md b/CHANGELOG.md
index c81234a..7b866ed 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [3.1.0] - 2021-06-13
+
+### Added
+- typescript.
+
 ## [3.0.0] - 2021-01-02
 
 ### Changed
diff --git a/README.md b/README.md
index dd4ab47..8bed578 100644
--- a/README.md
+++ b/README.md
@@ -6,12 +6,15 @@
 
 A wrapper around javascript array push/pop with a standard stack interface.
 
-# Table of Contents
+<img src="https://user-images.githubusercontent.com/6517308/121813242-859a9700-cc6b-11eb-99c0-49e5bb63005b.jpg">
+
+
+# Contents
 * [Install](#install)
 * [require](#require)
 * [import](#import)
 * [API](#api)
-  * [Construction](#construction)
+  * [constructor](#constructor)
   * [.push(element)](#pushelement)
   * [.peek()](#peek)
   * [.pop()](#pop)
@@ -29,21 +32,23 @@ A wrapper around javascript array push/pop with a standard stack interface.
 npm install --save @datastructures-js/stack
 ```
 
-### require
+### JS
 ```js
 const { Stack } = require('@datastructures-js/stack');
 ```
 
-### import
+### TS
 ```js
 import { Stack } from '@datastructures-js/stack';
 ```
+
 ## API
 
-### Construction
+### constructor
 
 #### using "new"
 
+##### JS
 ```js
 // empty stack
 const stack = new Stack();
@@ -52,8 +57,18 @@ const stack = new Stack();
 const stack = new Stack([10, 3, 8, 40, 1]);
 ```
 
+##### TS
+```TS
+// empty stack
+const stack = new Stack<number>();
+
+// from an array
+const stack = new Stack<number>([10, 3, 8, 40, 1]);
+```
+
 #### using ".fromArray"
 
+##### JS
 ```js
 // empty stack
 const stack = Stack.fromArray([]);
@@ -66,7 +81,12 @@ const stack = Stack.fromArray(list);
 const stack = Stack.fromArray(list.slice());
 ```
 
-### .push(element)
+##### TS
+```ts
+const stack = Stack.fromArray<number>([10, 3, 8, 40, 1]);
+```
+
+### .push(element: T)
 push an element to the top of the stack.
 
 <table>
@@ -76,14 +96,14 @@ push an element to the top of the stack.
     <th align="center">runtime</th>
   </tr>
   <tr>
-    <td align="center">element: any</td>
-    <td align="center">Stack</td>
+    <td align="center">element: T</td>
+    <td align="center">Stack&lt;T&gt;</td>
     <td align="center">O(1)</td>
   </tr>
 </table>
 
 ```js
-stack.push('test');
+stack.push(11);
 ```
 
 ### .peek()
@@ -95,13 +115,13 @@ returns the top element in the stack.
     <th align="center">runtime</th>
   </tr>
   <tr>
-    <td align="center">any</td>
+    <td align="center">T</td>
     <td align="center">O(1)</td>
   </tr>
 </table>
 
 ```js
-console.log(stack.peek()); // test
+console.log(stack.peek()); // 11
 ```
 
 ### .pop()
@@ -113,13 +133,13 @@ removes and returns the top element of the stack.
     <th align="center">runtime</th>
   </tr>
   <tr>
-    <td align="center">any</td>
+    <td align="center">T</td>
     <td align="center">O(1)</td>
   </tr>
 </table>
 
 ```js
-console.log(stack.pop()); // test
+console.log(stack.pop()); // 11
 console.log(stack.peek()); // null
 ```
 
@@ -138,7 +158,7 @@ checks if the stack is empty.
 </table>
 
 ```js
-stack.push('test');
+stack.push(11);
 console.log(stack.isEmpty()); // false
 ```
 
diff --git a/index.js b/index.js
index a362403..5bda705 100644
--- a/index.js
+++ b/index.js
@@ -1,3 +1,3 @@
-const Stack = require('./src/stack');
+const { Stack } = require('./src/stack');
 
 exports.Stack = Stack;
diff --git a/package.json b/package.json
index f32ad9f..3d55423 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@datastructures-js/stack",
-  "version": "3.0.0",
+  "version": "3.1.0",
   "description": "stack implementation in javascript",
   "main": "index.js",
   "scripts": {
diff --git a/src/stack.d.ts b/src/stack.d.ts
new file mode 100644
index 0000000..2f47111
--- /dev/null
+++ b/src/stack.d.ts
@@ -0,0 +1,12 @@
+export class Stack<T> {
+  constructor(elements?: T[]);
+  isEmpty(): boolean;
+  size(): number;
+  peek(): T;
+  push(element: T): Stack<T>;
+  pop(): T;
+  toArray(): T[];
+  clear(): void;
+  clone(): Stack<T>;
+  static fromArray<T>(elements: T[]): Stack<T>;
+}
diff --git a/src/stack.js b/src/stack.js
index 009abae..c5a38be 100644
--- a/src/stack.js
+++ b/src/stack.js
@@ -101,4 +101,4 @@ class Stack {
   }
 }
 
-module.exports = Stack;
+exports.Stack = Stack;
diff --git a/test/stack.test.js b/test/stack.test.js
index 418a73e..b61d512 100644
--- a/test/stack.test.js
+++ b/test/stack.test.js
@@ -1,5 +1,5 @@
 const { expect } = require('chai');
-const Stack = require('../src/stack');
+const { Stack } = require('../src/stack');
 
 describe('stack tests', () => {
   const stack = new Stack();