diff --git a/__tests__/krakenClient/init.js b/__tests__/krakenClient/init.js
new file mode 100644
index 0000000..f70e3d7
--- /dev/null
+++ b/__tests__/krakenClient/init.js
@@ -0,0 +1,24 @@
+const KrakenClient = require('../../kraken.js')
+
+describe('KrakenClient', async ()=>{
+    it('[Constructor] null param', ()=>{
+        try{ new KrakenClient() }
+        catch (e) {
+            expect(e.message).toBe('[Error] null key or secret')
+        }
+    })
+
+    it('[Constructor]', ()=>{
+        const key = 'mockKey'
+        const secret = 'mockSecret'
+        const kc = new KrakenClient(key, secret)
+        const reqConfig = require('../../config/request.json')
+
+        expect(kc.config).toEqual({
+            ...reqConfig,
+            key,
+            secret
+        })
+    })
+
+})
\ No newline at end of file
diff --git a/__tests__/lib/signature.js b/__tests__/lib/signature.js
new file mode 100644
index 0000000..8f312b7
--- /dev/null
+++ b/__tests__/lib/signature.js
@@ -0,0 +1,13 @@
+const {getMessageSignature} = require('../../lib/signature')
+
+describe('KrakenClient', async ()=>{
+    it('[Constructor] null param', ()=>{
+        const path = '/mock/path'
+        const request = {mock:'foo'}
+        const secret = 'mockSecret'
+        const nonce = 'mockNonce'
+        const result = getMessageSignature(path, request, secret, nonce)
+
+        expect(result).toBe('VP8viIhM4IDc0gOPRN4oyDqyBr5/f/rSWMMt/NGjwlq9NcmcSnZESpQ1aT4lETVzmyfzUbR6cIi8+2V1wTWtlQ==')
+    })
+})
\ No newline at end of file
diff --git a/config/methods.json b/config/methods.json
new file mode 100644
index 0000000..5430270
--- /dev/null
+++ b/config/methods.json
@@ -0,0 +1,4 @@
+{
+	"public"  : [ "Time", "Assets", "AssetPairs", "Ticker", "Depth", "Trades", "Spread", "OHLC" ],
+	"private" : [ "Balance", "TradeBalance", "OpenOrders", "ClosedOrders", "QueryOrders", "TradesHistory", "QueryTrades", "OpenPositions", "Ledgers", "QueryLedgers", "TradeVolume", "AddOrder", "CancelOrder", "DepositMethods", "DepositAddresses", "DepositStatus", "WithdrawInfo", "Withdraw", "WithdrawStatus", "WithdrawCancel" ]
+}
\ No newline at end of file
diff --git a/config/request.json b/config/request.json
new file mode 100644
index 0000000..cad1051
--- /dev/null
+++ b/config/request.json
@@ -0,0 +1,5 @@
+{
+	"url"     : "https://api.kraken.com",
+	"version" : 0,
+	"timeout" : 5000
+}
\ No newline at end of file
diff --git a/example/basic.js b/example/basic.js
new file mode 100644
index 0000000..e4274d8
--- /dev/null
+++ b/example/basic.js
@@ -0,0 +1,11 @@
+const key = process.env.KRAKEN_API_KEY 			// replace your key here
+const secret = process.env.KRAKEN_API_SECRET	// replace your secret here
+const KrakenClient = require('../kraken.js')
+
+(async () => {
+	// Display user's balance
+	console.log(await kraken.api('Balance'));
+
+	// Get Ticker Info
+	console.log(await kraken.api('Ticker', { pair : 'XXBTZUSD' }));
+})();
\ No newline at end of file
diff --git a/kraken.js b/kraken.js
index 4cedb7f..f839702 100644
--- a/kraken.js
+++ b/kraken.js
@@ -1,31 +1,12 @@
 const got    = require('got');
-const crypto = require('crypto');
 const qs     = require('qs');
+const {getMessageSignature} = require('./lib/signature')
 
 // Public/Private method names
-const methods = {
-	public  : [ 'Time', 'Assets', 'AssetPairs', 'Ticker', 'Depth', 'Trades', 'Spread', 'OHLC' ],
-	private : [ 'Balance', 'TradeBalance', 'OpenOrders', 'ClosedOrders', 'QueryOrders', 'TradesHistory', 'QueryTrades', 'OpenPositions', 'Ledgers', 'QueryLedgers', 'TradeVolume', 'AddOrder', 'CancelOrder', 'DepositMethods', 'DepositAddresses', 'DepositStatus', 'WithdrawInfo', 'Withdraw', 'WithdrawStatus', 'WithdrawCancel' ],
-};
+const methods = require('./config/methods.json');
 
 // Default options
-const defaults = {
-	url     : 'https://api.kraken.com',
-	version : 0,
-	timeout : 5000,
-};
-
-// Create a signature for a request
-const getMessageSignature = (path, request, secret, nonce) => {
-	const message       = qs.stringify(request);
-	const secret_buffer = new Buffer(secret, 'base64');
-	const hash          = new crypto.createHash('sha256');
-	const hmac          = new crypto.createHmac('sha512', secret_buffer);
-	const hash_digest   = hash.update(nonce + message).digest('binary');
-	const hmac_digest   = hmac.update(path + hash_digest, 'binary').digest('base64');
-
-	return hmac_digest;
-};
+const defaults = require('./config/request.json');
 
 // Send an API request
 const rawRequest = async (url, headers, data, timeout) => {
@@ -67,12 +48,12 @@ const rawRequest = async (url, headers, data, timeout) => {
  */
 class KrakenClient {
 	constructor(key, secret, options) {
+		if(!key || !secret) throw new Error('[Error] null key or secret')
+
 		// Allow passing the OTP as the third argument for backwards compatibility
-		if(typeof options === 'string') {
-			options = { otp : options };
-		}
+		if(typeof options === 'string') options = { otp : options };
 
-		this.config = Object.assign({ key, secret }, defaults, options);
+		this.config = { ...defaults, key, secret, options};
 	}
 
 	/**
@@ -107,9 +88,7 @@ class KrakenClient {
 	 * @param  {Function} callback A callback function to be executed when the request is complete
 	 * @return {Object}            The request object
 	 */
-	publicMethod(method, params, callback) {
-		params = params || {};
-
+	publicMethod(method, params = {}, callback) {
 		// Default params to empty object
 		if(typeof params === 'function') {
 			callback = params;
@@ -136,9 +115,7 @@ class KrakenClient {
 	 * @param  {Function} callback A callback function to be executed when the request is complete
 	 * @return {Object}            The request object
 	 */
-	privateMethod(method, params, callback) {
-		params = params || {};
-
+	privateMethod(method, params = {}, callback) {
 		// Default params to empty object
 		if(typeof params === 'function') {
 			callback = params;
diff --git a/lib/signature.js b/lib/signature.js
new file mode 100644
index 0000000..dcb213e
--- /dev/null
+++ b/lib/signature.js
@@ -0,0 +1,15 @@
+const crypto = require('crypto');
+const qs     = require('qs');
+
+// Create a signature for a request
+const getMessageSignature = (path='', request={}, secret='', nonce='') => {
+	const message       = qs.stringify(request);
+	const secret_buffer = new Buffer(secret, 'base64');
+	const hash          = new crypto.createHash('sha256');
+	const hmac          = new crypto.createHmac('sha512', secret_buffer);
+	const hash_digest   = hash.update(nonce + message).digest('binary');
+	const hmac_digest   = hmac.update(path + hash_digest, 'binary').digest('base64');
+	return hmac_digest;
+};
+
+module.exports = {getMessageSignature};
\ No newline at end of file
diff --git a/package.json b/package.json
index 5ec4452..0f879d6 100644
--- a/package.json
+++ b/package.json
@@ -2,6 +2,9 @@
   "name": "kraken-api",
   "version": "1.0.0",
   "description": "kraken.com API client library for NodeJS",
+  "scripts": {
+    "test": "jest"
+  },
   "keywords": [
     "kraken",
     "api",
@@ -27,5 +30,8 @@
     "url": "https://github.com/nothingisdead/npm-kraken-api/issues",
     "email": "rbmyr8@gmail.com"
   },
-  "readmeFilename": "README.md"
+  "readmeFilename": "README.md",
+  "devDependencies": {
+    "jest": "^22.4.3"
+  }
 }