diff --git a/.eslintrc.json b/.eslintrc.json
index 0c9820d..9483d30 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -6,7 +6,7 @@
   },
   "parserOptions": {
     "sourceType": "module",
-    "ecmaVersion": 9
+    "ecmaVersion": 10
   },
   "rules": {
     "curly": "error",
diff --git a/README.md b/README.md
index 47a4a94..f32a4e6 100644
--- a/README.md
+++ b/README.md
@@ -13,8 +13,8 @@ npm install poloniex-node-api
 ### PublicClient
 
 ```javascript
-const Poloniex = require('poloniex-node-api');
-const publicClient = new Poloniex.PublicClient();
+const { PublicClient } = require('poloniex-node-api');
+const publicClient = new PublicClient();
 ```
 
 - [`getTickers`](https://docs.poloniex.com/?shell#returnticker)
@@ -116,6 +116,8 @@ try {
 - `cb`
 
 ```javascript
+const _method = 'getLoanOrders';
+const options = { currency: 'BTC' };
 const callback = (error, data) => {
   if (error) {
     console.error(error);
@@ -123,26 +125,7 @@ const callback = (error, data) => {
     console.log(data);
   }
 };
-publicClient.cb('getLoanOrders', callback, { currency: 'BTC' });
-```
-
-- `request`
-
-```javascript
-publicClient
-  .request({
-    method: 'GET',
-    qs: {
-      command: 'return24hVolume',
-    },
-    url: 'https://poloniex.com/public',
-  })
-  .then(data => {
-    console.log(data);
-  })
-  .catch(error => {
-    console.error(error);
-  });
+publicClient.cb({ _method, ...options }, callback);
 ```
 
 ### AuthenticatedClient
@@ -150,70 +133,69 @@ publicClient
 ```javascript
 const key = 'poloniexapikey';
 const secret = 'poloniexapisecret';
-const Poloniex = require('poloniex-node-api');
-const AuthenticatedClient = new Poloniex.AuthenticatedClient({ key, secret });
+const { AuthenticatedClient } = require('poloniex-node-api');
+const authClient = new AuthenticatedClient({ key, secret });
 ```
 
 - [`getBalances`](https://docs.poloniex.com/?shell#returnbalances)
 
 ```javascript
-const balances = await AuthenticatedClient.getBalances();
+const balances = await authClient.getBalances();
 ```
 
 - [`getCompleteBalances`](https://docs.poloniex.com/?shell#returncompletebalances)
 
 ```javascript
 const account = 'all';
-const balances = await AuthenticatedClient.getCompleteBalances({ account });
+const balances = await authClient.getCompleteBalances({ account });
 ```
 
 - [`getDepositAddresses`](https://docs.poloniex.com/?shell#returndepositaddresses)
 
 ```javascript
-const addresses = await AuthenticatedClient.getDepositAddresses();
+const addresses = await authClient.getDepositAddresses();
 ```
 
 - [`getNewAddress`](https://docs.poloniex.com/?shell#generatenewaddress)
 
 ```javascript
-const addresses = await AuthenticatedClient.getNewAddress({ currency: 'ZEC' });
+const addresses = await authClient.getNewAddress({ currency: 'ZEC' });
 ```
 
 - [`getDepositsWithdrawals`](https://docs.poloniex.com/?shell#returndepositswithdrawals)
 
 ```javascript
-const deposits_withdrawals = await AuthenticatedClient.getDepositsWithdrawals({
-  start: 1539954535,
-  end: 1540314535,
-});
+const start = 1539954535;
+const end = 1540314535;
+const result = await authClient.getDepositsWithdrawals({ start, end });
 ```
 
 - [`getOpenOrders`](https://docs.poloniex.com/?shell#returnopenorders)
 
 ```javascript
 const currencyPair = 'BTC_DASH';
-const orders = await AuthenticatedClient.getOpenOrders({ currencyPair });
+const orders = await authClient.getOpenOrders({ currencyPair });
 ```
 
 - [`getHistoryTrades`](https://docs.poloniex.com/?shell#returntradehistory-private)
 
 ```javascript
 const currencyPair = 'BTC_ETC';
-const trades = await AuthenticatedClient.getHistoryTrades({ currencyPair });
+const trades = await authClient.getHistoryTrades({ currencyPair });
 ```
 
 - [`getOrderTrades`](https://docs.poloniex.com/?shell#returntradehistory-private)
 
 ```javascript
 const orderNumber = 96238912842;
-const trades = await AuthenticatedClient.getOrderTrades({ orderNumber });
+const trades = await authClient.getOrderTrades({ orderNumber });
 ```
 
 - [`getOrderStatus`](https://docs.poloniex.com/?shell#returnorderstatus)
 
 ```javascript
 const orderNumber = 96238912842;
-const trades = await AuthenticatedClient.getOrderStatus({ orderNumber });
+const trades = await authClient.getOrderStatus({ orderNumber });
 ```
 
 - [`buy`](https://docs.poloniex.com/?shell#buy)
@@ -222,7 +204,7 @@ const trades = await AuthenticatedClient.getOrderStatus({ orderNumber });
 const currencyPair = 'BTC_ETH';
 const rate = 0.01;
 const amount = 1;
-const order = await AuthenticatedClient.buy({ currencyPair, rate, amount });
+const order = await authClient.buy({ currencyPair, rate, amount });
 ```
 
 - [`sell`](https://docs.poloniex.com/?shell#sell)
@@ -231,21 +213,21 @@ const order = await AuthenticatedClient.buy({ currencyPair, rate, amount });
 const currencyPair = 'BTC_ETH';
 const rate = 10;
 const amount = 1;
-const order = await AuthenticatedClient.sell({ currencyPair, rate, amount });
+const order = await authClient.sell({ currencyPair, rate, amount });
 ```
 
 - [`cancelOrder`](https://docs.poloniex.com/?shell#cancelorder)
 
 ```javascript
 const orderNumber = 514845991795;
-const order = await AuthenticatedClient.cancelOrder({ orderNumber });
+const order = await authClient.cancelOrder({ orderNumber });
 ```
 
 - [`cancelAllOrders`](https://docs.poloniex.com/?shell#cancelallorders)
 
 ```javascript
 const currencyPair = 'BTC_ETH';
-const orders = await AuthenticatedClient.cancelAllOrders({ currencyPair });
+const orders = await authClient.cancelAllOrders({ currencyPair });
 ```
 
 - [`moveOrder`](https://docs.poloniex.com/?shell#moveorder)
@@ -253,7 +235,7 @@ const orders = await AuthenticatedClient.cancelAllOrders({ currencyPair });
 ```javascript
 const orderNumber = 514851026755;
 const rate = 0.00015;
-const result = await AuthenticatedClient.moveOrder({ rate, orderNumber });
+const result = await authClient.moveOrder({ rate, orderNumber });
 ```
 
 - [`withdraw`](https://docs.poloniex.com/?shell#withdraw)
@@ -263,7 +245,7 @@ const currency = 'EOS';
 const amount = 1000;
 const address = 'eos-address';
 const paymentId = 1234567890;
-const result = await AuthenticatedClient.withdraw({
+const result = await authClient.withdraw({
   currency,
   amount,
   address,
@@ -274,7 +256,7 @@ const result = await AuthenticatedClient.withdraw({
 - [`getFeeInfo`](https://docs.poloniex.com/?shell#returnfeeinfo)
 
 ```javascript
-const fees = await AuthenticatedClient.getFeeInfo();
+const fees = await authClient.getFeeInfo();
 ```
 
 - [`getAvailableAccountBalances`](https://docs.poloniex.com/?shell#returnavailableaccountbalances)
@@ -307,7 +289,7 @@ const transfer = AuthenticatedClient.transferBalance({
 - [`getMarginAccountSummary`](https://docs.poloniex.com/?shell#returnmarginaccountsummary)
 
 ```javascript
-const summary = await AuthenticatedClient.getMarginAccountSummary();
+const summary = await authClient.getMarginAccountSummary();
 ```
 
 - [`marginBuy`](https://docs.poloniex.com/?shell#marginbuy)
@@ -317,7 +299,7 @@ const currencyPair = 'BTC_ETH';
 const rate = 0.01;
 const amount = 1;
 const lendingRate = 0.01;
-const order = await AuthenticatedClient.marginBuy({
+const order = await authClient.marginBuy({
   currencyPair,
   rate,
   amount,
@@ -332,7 +314,7 @@ const currencyPair = 'BTC_ETH';
 const rate = 10;
 const amount = 1;
 const lendingRate = 0.015;
-const order = await AuthenticatedClient.marginSell({
+const order = await authClient.marginSell({
   currencyPair,
   rate,
   amount,
@@ -344,16 +326,14 @@ const order = await AuthenticatedClient.marginSell({
 
 ```javascript
 const currencyPair = 'BTC_ETH';
-const position = await AuthenticatedClient.getMarginPosition({ currencyPair });
+const position = await authClient.getMarginPosition({ currencyPair });
 ```
 
 - [`closeMarginPosition`](https://docs.poloniex.com/?shell#closemarginposition)
 
 ```javascript
 const currencyPair = 'BTC_ETH';
-const position = await AuthenticatedClient.closeMarginPosition({
-  currencyPair,
-});
+const position = await authClient.closeMarginPosition({ currencyPair });
 ```
 
 - [`createLoanOffer`](https://docs.poloniex.com/?shell#createloanoffer)
@@ -364,7 +344,7 @@ const amount = 0.1;
 const duration = 2;
 const autoRenew = 0;
 const lendingRate = 0.015;
-const offer = await AuthenticatedClient.createLoanOffer({
+const offer = await authClient.createLoanOffer({
   currency,
   amount,
   duration,
@@ -377,19 +357,19 @@ const offer = await AuthenticatedClient.createLoanOffer({
 
 ```javascript
 const orderNumber = 1002013188;
-const offer = await AuthenticatedClient.cancelLoanOffer({ orderNumber });
+const offer = await authClient.cancelLoanOffer({ orderNumber });
 ```
 
 - [`getOpenLoanOffers`](https://docs.poloniex.com/?shell#returnopenloanoffers)
 
 ```javascript
-const offers = await AuthenticatedClient.getOpenLoanOffers();
+const offers = await authClient.getOpenLoanOffers();
 ```
 
 - [`getActiveLoans`](https://docs.poloniex.com/#returnactiveloans)
 
 ```javascript
-const loans = await AuthenticatedClient.getActiveLoans();
+const loans = await authClient.getActiveLoans();
 ```
 
 - [`getLendingHistory`](https://docs.poloniex.com/#returnlendinghistory)
@@ -398,24 +378,14 @@ const loans = await AuthenticatedClient.getActiveLoans();
 const start = 1483228800;
 const end = 1483315200;
 const limits = 100;
-const history = await AuthenticatedClient.getLendingHistory({
-  start,
-  end,
-  limits,
-});
+const history = await authClient.getLendingHistory({ start, end, limits });
 ```
 
 - [`toggleAutoRenew`](https://docs.poloniex.com/#toggleautorenew)
 
 ```javascript
 const orderNumber = 1002013188;
-const result = await AuthenticatedClient.toggleAutoRenew({ orderNumber });
-```
-
-- `post`
-
-```javascript
-AuthenticatedClient.post({ command: 'returnCompleteBalances' });
+const result = await authClient.toggleAutoRenew({ orderNumber });
 ```
 
 ### WebsocketClient
@@ -424,8 +394,8 @@ AuthenticatedClient.post({ command: 'returnCompleteBalances' });
 const key = 'poloniexapikey';
 const secret = 'poloniexapisecret';
 const channels = [1000, 'BTC_DOGE'];
-const Poloniex = require('poloniex-node-api');
-const websocket = new Poloniex.WebsocketClient({ key, secret, channels });
+const { WebsocketClient } = require('poloniex-node-api');
+const websocket = new WebsocketClient({ key, secret, channels });
 websocket.on('open', () => {
   console.log('open');
 });
@@ -464,16 +434,6 @@ websocket.subscribe(1003);
 websocket.unsubscribe('BTC_ZEC');
 ```
 
-### SignRequest
-
-```javascript
-const Poloniex = require('poloniex-node-api');
-const auth = { key: 'apikey', secret: 'apisecret' };
-const data = { form: { command: 'returnBalances', nonce: 154264078495300 } };
-const { key, sign } = Poloniex.SignRequest(auth, data);
-console.log(sign);
-```
-
 ### Test
 
 ```bash
diff --git a/index.d.ts b/index.d.ts
index e8ae0e3..8120932 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -1,6 +1,6 @@
 import { EventEmitter } from 'events';
 
-declare module 'poloniex' {
+declare module 'poloniex-node-api' {
   export type callback<T> = (error: any, data: T) => void;
 
   export type TickerInfo = {
@@ -109,6 +109,10 @@ declare module 'poloniex' {
     } & getOptions;
   };
 
+  export type CBOptions = {
+    _method: string;
+  };
+
   export type CurrencyPairFilter = {
     currencyPair?: string;
   };
@@ -599,7 +603,7 @@ declare module 'poloniex' {
 
     request(options: requestOptions): Promise<any>;
 
-    cb(method: string, callback: callback<any>, options?: any);
+    cb(options: CBOptions, callback: callback<any>);
 
     getTickers(): Promise<Tickers>;
 
@@ -616,7 +620,7 @@ declare module 'poloniex' {
     getLoanOrders(options: CurrencyFilter): Promise<Loans>;
   }
 
-  export class AuthenticatedClient {
+  export class AuthenticatedClient extends PublicClient {
     constructor(options: AuthenticatedClientOptions);
 
     post(options: getOptions): Promise<any>;
diff --git a/index.js b/index.js
index a19fccf..c3e4622 100644
--- a/index.js
+++ b/index.js
@@ -1,6 +1,5 @@
 module.exports = {
   AuthenticatedClient: require('./lib/authenticated.js'),
   PublicClient: require('./lib/public.js'),
-  SignRequest: require('./lib/signer.js'),
   WebsocketClient: require('./lib/websocket.js'),
 };
diff --git a/lib/authenticated.js b/lib/authenticated.js
index 818fc1c..dd45116 100644
--- a/lib/authenticated.js
+++ b/lib/authenticated.js
@@ -11,8 +11,8 @@ class AuthenticatedClient extends PublicClient {
    * @param {string} [options.currencyPair] - If `currencyPair` is provided then it will be used in all future requests that require `currencyPair` but it is omitted (not applied to requests where `currencyPair` is optional).
    * @throws Will throw an error if incomplete authentication credentials are provided.
    * @example
-   * const Poloniex = require('poloniex-node-api');
-   * const AuthenticatedClient = new Poloniex.AuthenticatedClient({
+   * const { AuthenticatedClient } = require('poloniex-node-api');
+   * const authClient = new AuthenticatedClient({
    *   key: 'my-api-key',
    *   secret: 'my-api-secret',
    * });
@@ -30,7 +30,7 @@ class AuthenticatedClient extends PublicClient {
    * @param {Object} options
    * @param {string} options.command
    * @example
-   * AuthenticatedClient.post({
+   * authClient.post({
    *   command: 'generateNewAddress',
    *   currency: 'ETH',
    * })
@@ -42,23 +42,21 @@ class AuthenticatedClient extends PublicClient {
    *   });
    * @description Make `POST` request.
    */
-  post(options) {
-    const { command } = options;
+  post({ ...form } = {}) {
+    const { command } = form;
     this._requireProperties(command);
 
+    form.nonce = this._nonce();
     const auth = { key: this.key, secret: this.secret };
-    const reqOptions = { form: this._removeUndefined(options), method: 'POST' };
-    reqOptions.timeout = this.timeout;
-    reqOptions.form.nonce = this._nonce();
+    const reqOptions = { form, method: 'POST', timeout: this.timeout };
     reqOptions.url = this.api_uri + '/tradingApi';
     reqOptions.headers = SignRequest(auth, reqOptions);
-
     return this.request(reqOptions);
   }
 
   /**
    * @example
-   * const balances = AuthenticatedClient.getBalances();
+   * const balances = authClient.getBalances();
    * @see {@link https://docs.poloniex.com/?shell#returnbalances|returnBalances}
    * @description Get all of your balances available for trade after having deducted all open orders.
    */
@@ -70,7 +68,7 @@ class AuthenticatedClient extends PublicClient {
    * @param {Object} [options]
    * @param {string} [options.account] - Set the `account` parameter to "all" to include your margin and lending accounts.
    * @example
-   * const balances = AuthenticatedClient.getCompleteBalances({ account: 'all' });
+   * const balances = authClient.getCompleteBalances({ account: 'all' });
    * @see {@link https://docs.poloniex.com/?shell#returncompletebalances|returnCompleteBalances}
    * @description Get all of your balances, including available balance, balance on orders, and the estimated BTC value of your balance.
    */
@@ -80,7 +78,7 @@ class AuthenticatedClient extends PublicClient {
 
   /**
    * @example
-   * const addresses = AuthenticatedClient.getDepositAddresses();
+   * const addresses = authClient.getDepositAddresses();
    * @see {@link https://docs.poloniex.com/?shell#returndepositaddresses|returnDepositAddresses}
    * @description Get all of your deposit addresses.
    */
@@ -92,7 +90,7 @@ class AuthenticatedClient extends PublicClient {
    * @param {Object} options
    * @param {string} options.currency - The currency to use for the deposit address.
    * @example
-   * const addresses = AuthenticatedClient.getNewAddress({ currency: 'BTC' });
+   * const addresses = authClient.getNewAddress({ currency: 'BTC' });
    * @see {@link https://docs.poloniex.com/?shell#generatenewaddress|generateNewAddress}
    * @description Generate a new deposit address.
    */
@@ -107,7 +105,7 @@ class AuthenticatedClient extends PublicClient {
    * @param {number} options.start - The start date of the range window in UNIX timestamp format.
    * @param {number} options.end - The end date of the range window in UNIX timestamp format.
    * @example
-   * const deposits = AuthenticatedClient.getDepositsWithdrawals({
+   * const deposits = authClient.getDepositsWithdrawals({
    *   start: 1539952118,
    *   end: 1540318271,
    * });
@@ -124,7 +122,7 @@ class AuthenticatedClient extends PublicClient {
    * @param {Object} [options]
    * @param {string} [options.currencyPair='all'] - The major and minor currency that define this market.
    * @example
-   * const orders = AuthenticatedClient.getOpenOrders();
+   * const orders = authClient.getOpenOrders();
    * @description Get your open orders for a given market.
    * @see {@link https://docs.poloniex.com/?shell#returnopenorders|returnOpenOrders}
    */
@@ -139,7 +137,7 @@ class AuthenticatedClient extends PublicClient {
    * @param {number} [options.end] - The end date of the range window in UNIX timestamp format.
    * @param {number} [options.limit] - You may optionally limit the number of entries returned using the "limit" parameter, up to a maximum of 10,000. If the "limit" parameter is not specified, no more than 500 entries will be returned.
    * @example
-   * const trades = AuthenticatedClient.getHistoryTrades();
+   * const trades = authClient.getHistoryTrades();
    * @description Get your trade history for a given market.
    * @see {@link https://docs.poloniex.com/?shell#returntradehistory-private|returnTradeHistory}
    */
@@ -157,7 +155,7 @@ class AuthenticatedClient extends PublicClient {
    * @param {Object} options
    * @param {number} options.orderNumber - The order number whose trades you wish to query.
    * @example
-   * const trades = AuthenticatedClient.getOrderTrades({ orderNumber: 96238912841 });
+   * const trades = authClient.getOrderTrades({ orderNumber: 96238912841 });
    * @description Get all trades involving a given order.
    * @see {@link https://docs.poloniex.com/?shell#returntradehistory-private|returnOrderTrades}
    */
@@ -171,7 +169,7 @@ class AuthenticatedClient extends PublicClient {
    * @param {Object} options
    * @param {string} options.orderNumber - The identifier of the order to return.
    * @example
-   * const trades = AuthenticatedClient.getOrderStatus({ orderNumber: 9623891284 });
+   * const trades = authClient.getOrderStatus({ orderNumber: 9623891284 });
    * @description Get the status of a given order.
    * @see {@link https://docs.poloniex.com/?shell#returnorderstatus|returnOrderStatus}
    */
@@ -193,7 +191,7 @@ class AuthenticatedClient extends PublicClient {
    * const currencyPair = 'BTC_ETH';
    * const rate = 0.01;
    * const amount = 1;
-   * const order = AuthenticatedClient.buy({ currencyPair, rate, amount });
+   * const order = authClient.buy({ currencyPair, rate, amount });
    * @description Places a limit buy order.
    * @see {@link https://docs.poloniex.com/?shell#buy|buy}
    */
@@ -230,7 +228,7 @@ class AuthenticatedClient extends PublicClient {
    * const currencyPair = 'BTC_ETH';
    * const rate = 0.01;
    * const amount = 1;
-   * const order = AuthenticatedClient.sell({ currencyPair, rate, amount });
+   * const order = authClient.sell({ currencyPair, rate, amount });
    * @description Places a limit sell order.
    * @see {@link https://docs.poloniex.com/?shell#sell|sell}
    */
@@ -259,7 +257,7 @@ class AuthenticatedClient extends PublicClient {
    * @param {Object} options
    * @param {string} options.orderNumber - The identity number of the order to be canceled.
    * @example
-   * const order = AuthenticatedClient.cancelOrder({ orderNumber: 514845991795 });
+   * const order = authClient.cancelOrder({ orderNumber: 514845991795 });
    * @description Cancel an order you have placed in a given market.
    * @see {@link https://docs.poloniex.com/?shell#cancelorder|cancelOrder}
    */
@@ -273,7 +271,7 @@ class AuthenticatedClient extends PublicClient {
    * @param {Object} [options]
    * @param {string} [options.currencyPair] - The base and quote currency that define a market.
    * @example
-   * const order = AuthenticatedClient.cancelAllOrders({ currencyPair: 'BTC_ETH' });
+   * const order = authClient.cancelAllOrders({ currencyPair: 'BTC_ETH' });
    * @description Cancel all open orders in a given market or, if no market is provided, all open orders in all markets.
    * @see {@link https://docs.poloniex.com/?shell#cancelallorders|cancelAllOrders}
    */
@@ -289,7 +287,7 @@ class AuthenticatedClient extends PublicClient {
    * @param {number} [options.postOnly] - Set to `1` if you want this buy order to only be placed if no portion of it fills immediately.
    * @param {number} [options.immediateOrCancel] - Set to `1` if this order can be partially or completely filled, but any portion of the order that cannot be filled immediately will be canceled.
    * @example
-   * const order = AuthenticatedClient.moveOrder({
+   * const order = authClient.moveOrder({
    *   orderNumber: 514851026755,
    *   rate: 0.00015,
    * });
@@ -317,7 +315,7 @@ class AuthenticatedClient extends PublicClient {
    * @param {string|number} [options.paymentId] - For withdrawals which support payment IDs.
    * @param {string} [options.currencyToWithdrawAs] - Set to `USDTTRON` and set `currency` to `USDT` to withdraw `USDT-TRON`.
    * @example
-   * const withdraw = AuthenticatedClient.withdraw({
+   * const withdraw = authClient.withdraw({
    *   currency: 'ETH',
    *   amount: 2,
    *   address: '0x84a90e21d9d02e30ddcea56d618aa75ba90331ff',
@@ -346,7 +344,7 @@ class AuthenticatedClient extends PublicClient {
 
   /**
    * @example
-   * const fees = AuthenticatedClient.getFeeInfo();
+   * const fees = authClient.getFeeInfo();
    * @see {@link https://docs.poloniex.com/?shell#returnfeeinfo|returnFeeInfo}
    * @description Get your current trading fees and trailing 30-day volume in BTC.
    */
@@ -358,7 +356,7 @@ class AuthenticatedClient extends PublicClient {
    * @param {Object} [options]
    * @param {string} [options.account] - `exchange`, `margin` or `lending`.
    * @example
-   * const balances = AuthenticatedClient.getAvailableAccountBalances({
+   * const balances = authClient.getAvailableAccountBalances({
    *   account: 'exchange',
    * });
    * @see {@link https://docs.poloniex.com/?shell#returnavailableaccountbalances|returnAvailableAccountBalances}
@@ -370,7 +368,7 @@ class AuthenticatedClient extends PublicClient {
 
   /**
    * @example
-   * const balances = AuthenticatedClient.getTradableBalances();
+   * const balances = authClient.getTradableBalances();
    * @see {@link https://docs.poloniex.com/?shell#returntradablebalances|returnTradableBalances}
    * @description Get your current tradable balances for each currency in each market for which margin trading is enabled.
    */
@@ -385,7 +383,7 @@ class AuthenticatedClient extends PublicClient {
    * @param {string} options.fromAccount - The account from which this value should be moved.
    * @param {string} options.toAccount - The account to which this value should be moved.
    * @example
-   * const transfer = AuthenticatedClient.transferBalance({
+   * const transfer = authClient.transferBalance({
    *   currency: 'ETH',
    *   amount: 10,
    *   fromAccount: 'lending',
@@ -408,7 +406,7 @@ class AuthenticatedClient extends PublicClient {
 
   /**
    * @example
-   * const summary = AuthenticatedClient.getMarginAccountSummary();
+   * const summary = authClient.getMarginAccountSummary();
    * @see {@link https://docs.poloniex.com/?shell#returnmarginaccountsummary|returnMarginAccountSummary}
    * @description Get a summary of your entire margin account.
    */
@@ -426,7 +424,7 @@ class AuthenticatedClient extends PublicClient {
    * const currencyPair = 'BTC_ETH';
    * const rate = 0.01;
    * const amount = 1;
-   * const order = AuthenticatedClient.marginBuy({ currencyPair, rate, amount });
+   * const order = authClient.marginBuy({ currencyPair, rate, amount });
    * @description Place a margin buy order in a given market.
    * @see {@link https://docs.poloniex.com/?shell#marginbuy|marginBuy}
    */
@@ -457,7 +455,7 @@ class AuthenticatedClient extends PublicClient {
    * const currencyPair = 'BTC_ETH';
    * const rate = 0.001;
    * const amount = 2;
-   * const order = AuthenticatedClient.marginSell({ currencyPair, rate, amount });
+   * const order = authClient.marginSell({ currencyPair, rate, amount });
    * @description Place a margin sell order in a given market.
    * @see {@link https://docs.poloniex.com/?shell#marginsell|marginSell}
    */
@@ -482,7 +480,7 @@ class AuthenticatedClient extends PublicClient {
    * @param {Object} [options]
    * @param {string} [options.currencyPair='all'] - The major and minor currency that define this market.
    * @example
-   * const position = AuthenticatedClient.getMarginPosition();
+   * const position = authClient.getMarginPosition();
    * @description Get information about your margin position in a given market.
    * @see {@link https://docs.poloniex.com/?shell#getmarginposition|getMarginPosition}
    */
@@ -495,7 +493,7 @@ class AuthenticatedClient extends PublicClient {
    * @param {string} [options.currencyPair] - The major and minor currency that define this market.
    * @example
    * const currencyPair = 'BTC_ETH';
-   * const position = AuthenticatedClient.closeMarginPosition({ currencyPair });
+   * const position = authClient.closeMarginPosition({ currencyPair });
    * @description Close your margin position in a given market using a market order.
    * @see {@link https://docs.poloniex.com/?shell#closemarginposition|closeMarginPosition}
    */
@@ -516,7 +514,7 @@ class AuthenticatedClient extends PublicClient {
    * const duration = 2;
    * const autoRenew = 0;
    * const lendingRate = 0.015;
-   * const offer = await AuthenticatedClient.createLoanOffer({
+   * const offer = await authClient.createLoanOffer({
    *   currency,
    *   amount,
    *   duration,
@@ -544,7 +542,7 @@ class AuthenticatedClient extends PublicClient {
    * @param {string} options.orderNumber - The identification number of the offer to be canceled.
    * @example
    * const orderNumber = 1002013188;
-   * const offer = await AuthenticatedClient.cancelLoanOffer({ orderNumber });
+   * const offer = await authClient.cancelLoanOffer({ orderNumber });
    * @description Cancel a loan offer.
    * @see {@link https://docs.poloniex.com/?shell#cancelloanoffer|cancelLoanOffer}
    */
@@ -556,7 +554,7 @@ class AuthenticatedClient extends PublicClient {
 
   /**
    * @example
-   * const offers = AuthenticatedClient.getOpenLoanOffers();
+   * const offers = authClient.getOpenLoanOffers();
    * @see {@link https://docs.poloniex.com/?shell#returnopenloanoffers|returnOpenLoanOffers}
    * @description Get your open loan offers for each currency.
    */
@@ -566,7 +564,7 @@ class AuthenticatedClient extends PublicClient {
 
   /**
    * @example
-   * const loans = await AuthenticatedClient.getActiveLoans();
+   * const loans = await authClient.getActiveLoans();
    * @description Get your active loans for each currency.
    * @see {@link https://docs.poloniex.com/#returnactiveloans|returnActiveLoans}
    */
@@ -580,7 +578,7 @@ class AuthenticatedClient extends PublicClient {
    * @param {number} [options.end] - The date in Unix timestamp format of the end of the window.
    * @param {number} [options.limit] - `limit` may also be specified to limit the number of rows returned.
    * @example
-   * const history = await AuthenticatedClient.getLendingHistory();
+   * const history = await authClient.getLendingHistory();
    * @description Get your lending history.
    * @see {@link https://docs.poloniex.com/#returnlendinghistory|returnLendingHistory}
    */
@@ -592,7 +590,7 @@ class AuthenticatedClient extends PublicClient {
    * @param {Object} options
    * @param {number} options.orderNumber - The identifier of the order you want to toggle.
    * @example
-   * const result = AuthenticatedClient.toggleAutoRenew({ orderNumber: 1002013188 });
+   * const result = authClient.toggleAutoRenew({ orderNumber: 1002013188 });
    * @description Toggle the autoRenew setting on an active loan
    * @see {@link https://docs.poloniex.com/#toggleautorenew|toggleAutoRenew}
    */
@@ -605,14 +603,14 @@ class AuthenticatedClient extends PublicClient {
   /**
    * @private
    * @example
-   * const nonce = AuthenticatedClient._nonce();
+   * const nonce = authClient._nonce();
    * @description Get new nonce.
    */
   _nonce() {
     if (typeof this.nonce === 'function') {
       return this.nonce();
     }
-    return !this.nonce ? (this.nonce = Date.now()) : ++this.nonce;
+    return (this.nonce = Date.now());
   }
 }
 
diff --git a/lib/public.js b/lib/public.js
index 66432d7..33b3287 100644
--- a/lib/public.js
+++ b/lib/public.js
@@ -1,4 +1,4 @@
-const request = require('request-promise');
+const request = require('request-promise-native');
 const {
   EXCHANGE_API_URL,
   DEFAULT_TIMEOUT,
@@ -7,6 +7,12 @@ const {
   HEADERS,
 } = require('./utilities');
 
+/**
+ * @callback Callback
+ * @param error
+ * @param data
+ */
+
 class PublicClient {
   /**
    * @param {Object} [options={}]
@@ -14,8 +20,9 @@ class PublicClient {
    * @param {string} [options.api_uri] - Overrides the default apiuri, if provided.
    * @param {number} [options.timeout] - Overrides the default timeout, if provided.
    * @example
-   * const Poloniex = require('poloniex-node-api');
-   * const publicClient = new Poloniex.PublicClient({ currencyPair: 'BTC_ETH' });
+   * const { PublicClient } = require('poloniex-node-api');
+   * const currencyPair = 'BTC_DASH';
+   * const publicClient = new PublicClient({ currencyPair });
    * @description Create PublicClient.
    */
   constructor({ currencyPair, api_uri, timeout } = {}) {
@@ -40,19 +47,19 @@ class PublicClient {
    * @throws Will throw an error if `options.command` is undefined.
    * @description Make `GET` request.
    */
-  get(options) {
-    const { command } = options;
+  get({ ...qs } = {}) {
+    const { command } = qs;
     this._requireProperties(command);
 
-    const reqOptions = { qs: this._removeUndefined(options), method: 'GET' };
-    reqOptions.timeout = this.timeout;
+    const reqOptions = { qs, method: 'GET', timeout: this.timeout };
     reqOptions.url = this.api_uri + '/public';
 
     return this.request(reqOptions);
   }
 
   /**
-   * @param {Object} [options]
+   * @private
+   * @param {Object} options
    * @example
    * publicClient
    *   .request({
@@ -85,16 +92,30 @@ class PublicClient {
             resolve(data);
           }
         })
-        .catch(error => reject(error));
+        .catch(error => reject(error.error || error));
     });
   }
 
-  cb(method, callback, options) {
+  /**
+   * @param {Object} options
+   * @param {string} options._method - Class method to call.
+   * @param {...*} [options.methodOptions]
+   * @param {Callback} callback
+   * @example
+   * publicClient.cb(
+   *   { _method: 'getLoanOrders', currency: 'BTC' },
+   *   (error, data) => {
+   *     if (error) {
+   *       console.error(error);
+   *     } else {
+   *       console.log(data);
+   *     }
+   *   }
+   * );
+   */
+  cb({ _method, ...options } = {}, callback) {
     try {
-      this[method]
-        .call(this, options)
-        .then(data => callback(null, data))
-        .catch(error => callback(error));
+      this[_method].call(this, options).then(data => callback(null, data));
     } catch (error) {
       callback(error);
     }
@@ -121,14 +142,11 @@ class PublicClient {
   }
 
   /**
-   * @param {Object} [options]
+   * @param {Object} [options={}]
    * @param {string} [options.currencyPair='all'] - A pair like `BTC_ETH` or `all`.
    * @param {number} [options.depth] - Max depth is `100`.
    * @example
-   * const book = await publicClient.getOrderBook({
-   *   depth: 25,
-   *   currencyPair: 'USDT_ZEC',
-   * });
+   * const books = await publicClient.getOrderBook();
    * @see {@link https://docs.poloniex.com/?shell#returnorderbook|returnOrderBook}
    * @description Get the order book for a given market.
    */
@@ -137,16 +155,12 @@ class PublicClient {
   }
 
   /**
-   * @param {Object} [options]
+   * @param {Object} [options={}]
    * @param {string} [options.currencyPair] - If `currencyPair` is not provided then the default currencyPair will be used.
    * @param {number} [options.start] - UNIX timestamp.
    * @param {number} [options.end] - UNIX timestamp.
    * @example
-   * const history = await publicClient.getTradeHistory({
-   *   currencyPair: 'USDT_ZEC',
-   *   start: 1410158328,
-   *   end: 1410488343,
-   * });
+   * const history = await publicClient.getTradeHistory();
    * @see {@link https://docs.poloniex.com/?shell#returntradehistory-public|returnTradeHistory}
    * @description Get the past 200 trades for a given market, or up to 1,000 trades between a range `start` and `end`.
    */
@@ -160,7 +174,7 @@ class PublicClient {
   }
 
   /**
-   * @param {Object} options
+   * @param {Object} options={}
    * @param {string} [options.currencyPair] - If `currencyPair` is not provided then the default currencyPair will be used.
    * @param {number} options.period - Candlestick period in seconds. Valid values are 300, 900, 1800, 7200, 14400, and 86400.
    * @param {number} options.start - UNIX timestamp.
@@ -201,7 +215,7 @@ class PublicClient {
    * @param {Object} options
    * @param {string} options.currency
    * @example
-   * const loans = publicClient.getLoanOrders({ currency: 'BTC' });
+   * const loans = await publicClient.getLoanOrders({ currency: 'BTC' });
    * @see {@link https://docs.poloniex.com/?shell#returnloanorders|returnLoanOrders}
    * @description Get the list of loan offers and demands for a given currency.
    */
@@ -226,16 +240,6 @@ class PublicClient {
       }
     }
   }
-
-  _removeUndefined(object) {
-    let newObject = object;
-    for (let key of Object.keys(object)) {
-      if (object[key] === undefined) {
-        delete newObject[key];
-      }
-    }
-    return newObject;
-  }
 }
 
 module.exports = PublicClient;
diff --git a/lib/signer.js b/lib/signer.js
index 161ccda..75dfb14 100644
--- a/lib/signer.js
+++ b/lib/signer.js
@@ -2,31 +2,26 @@ const crypto = require('crypto');
 const querystring = require('querystring');
 
 /**
+ * @private
  * @description SignRequest.
  * @param {Object} auth
  * @param {string} auth.key - The API key.
  * @param {string} auth.secret - The API secret.
- * @param {Object} [options={}] - Data to sign.
+ * @param {Object} options
+ * @param {Object} options.form - The form to sign.
  * @example
- * const signature = Poloniex.SignRequest(
- *   { key: 'my-api-key', secret: 'my-api-secret' },
- *   { form: { command: 'returnBalances', nonce: 154264078495300 } }
- * );
+ * const auth = { key: 'my-api-key', secret: 'my-api-secret' };
+ * const data = { form: { command: 'returnBalances', nonce: 154264078495300 } };
+ * const signature = SignRequest(auth, data);
  * @returns {Object} The object containg the key and the signature.
  */
-const SignRequest = (auth, options = {}) => {
-  let form = '';
-  if (options.qs && Object.keys(options.qs).length) {
-    form = '?' + querystring.stringify(options.qs);
-  } else if (options.form) {
-    form = querystring.stringify(options.form);
-  }
-
+const SignRequest = (auth, options) => {
+  const data = querystring.stringify(options.form);
   return {
     key: auth.key,
     sign: crypto
       .createHmac('sha512', auth.secret)
-      .update(form)
+      .update(data)
       .digest('hex'),
   };
 };
diff --git a/lib/websocket.js b/lib/websocket.js
index ea5fdf2..570c950 100644
--- a/lib/websocket.js
+++ b/lib/websocket.js
@@ -298,7 +298,7 @@ class WebsocketClient extends EventEmitter {
     if (typeof this.nonce === 'function') {
       return this.nonce();
     }
-    return !this.nonce ? (this.nonce = Date.now()) : ++this.nonce;
+    return (this.nonce = Date.now());
   }
 }
 
diff --git a/package-lock.json b/package-lock.json
index afda963..2a949e2 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,22 +1,22 @@
 {
   "name": "poloniex-node-api",
-  "version": "0.3.6",
+  "version": "0.4.0",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
     "@babel/code-frame": {
-      "version": "7.0.0",
-      "resolved": "https://registry.npmjs.org/@babel/code-frame/-/code-frame-7.0.0.tgz",
-      "integrity": "sha512-OfC2uemaknXr87bdLUkWog7nYuliM9Ij5HUcajsVcMCpQrcLmtxRbVFTIqmcSkSeYRBFBRxs2FiUqFJDLdiebA==",
+      "version": "7.5.5",
+      "resolved": "https://registry.npmjs.org/@babel/code-frame/-/code-frame-7.5.5.tgz",
+      "integrity": "sha512-27d4lZoomVyo51VegxI20xZPuSHusqbQag/ztrBC7wegWoQ1nLREPVSKSW8byhTlzTKyNE4ifaTA6lCp7JjpFw==",
       "dev": true,
       "requires": {
         "@babel/highlight": "^7.0.0"
       }
     },
     "@babel/highlight": {
-      "version": "7.0.0",
-      "resolved": "https://registry.npmjs.org/@babel/highlight/-/highlight-7.0.0.tgz",
-      "integrity": "sha512-UFMC4ZeFC48Tpvj7C8UgLvtkaUuovQX+5xNWrsIoMG8o2z+XFKjKaN9iVmS84dPwVN00W4wPmqvYoZF3EGAsfw==",
+      "version": "7.5.0",
+      "resolved": "https://registry.npmjs.org/@babel/highlight/-/highlight-7.5.0.tgz",
+      "integrity": "sha512-7dV4eu9gBxoM0dAnj/BCFDW9LFU0zvTrkq0ugM7pnHEgguOEeOz1so2ZghEdzviYzQEED0r4EAgpsBChKy1TRQ==",
       "dev": true,
       "requires": {
         "chalk": "^2.0.0",
@@ -31,9 +31,9 @@
       "dev": true
     },
     "acorn": {
-      "version": "6.1.1",
-      "resolved": "https://registry.npmjs.org/acorn/-/acorn-6.1.1.tgz",
-      "integrity": "sha512-jPTiwtOxaHNaAPg/dmrJ/beuzLRnXtB0kQPQ8JpotKJgTB6rX6c8mlf315941pyjBSaPg8NHXS9fhP4u17DpGA==",
+      "version": "6.2.1",
+      "resolved": "https://registry.npmjs.org/acorn/-/acorn-6.2.1.tgz",
+      "integrity": "sha512-JD0xT5FCRDNyjDda3Lrg/IxFscp9q4tiYtxE1/nOzlKCk7hIRuYjhq1kCNkbPjMRMZuFq20HNQn1I9k8Oj0E+Q==",
       "dev": true
     },
     "acorn-jsx": {
@@ -43,9 +43,9 @@
       "dev": true
     },
     "ajv": {
-      "version": "6.10.0",
-      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.10.0.tgz",
-      "integrity": "sha512-nffhOpkymDECQyR0mnsUtoCE8RlX38G0rYP+wgLWFyZuUyuuojSSvi/+euOiQBIn63whYwYVIIH1TvE3tu4OEg==",
+      "version": "6.10.2",
+      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.10.2.tgz",
+      "integrity": "sha512-TXtUUEYHuaTEbLZWIKUr5pmBuhDLy+8KYtPYdcV8qC+pOZL+NKqYwvWSRrVXHn+ZmRRAu8vJTAznH7Oag6RVRw==",
       "requires": {
         "fast-deep-equal": "^2.0.1",
         "fast-json-stable-stringify": "^2.0.0",
@@ -151,7 +151,8 @@
     "bluebird": {
       "version": "3.5.5",
       "resolved": "https://registry.npmjs.org/bluebird/-/bluebird-3.5.5.tgz",
-      "integrity": "sha512-5am6HnnfN+urzt4yfg7IgTbotDjIT/u8AJpEt0sIU9FtXfVeezXAPKswrG+xKUCOYAINpSdgZVDU6QFh+cuH3w=="
+      "integrity": "sha512-5am6HnnfN+urzt4yfg7IgTbotDjIT/u8AJpEt0sIU9FtXfVeezXAPKswrG+xKUCOYAINpSdgZVDU6QFh+cuH3w==",
+      "dev": true
     },
     "brace-expansion": {
       "version": "1.1.11",
@@ -193,14 +194,6 @@
       "dev": true,
       "requires": {
         "lodash": "^4.17.14"
-      },
-      "dependencies": {
-        "lodash": {
-          "version": "4.17.15",
-          "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.15.tgz",
-          "integrity": "sha512-8xOcRHvCjnocdS5cpwXQXVzmmh5e5+saE2QGoeQmbKmRS6J3VQppPOIt0MnmE+4xlZoumy0GPG0D0MVIQbNA1A==",
-          "dev": true
-        }
       }
     },
     "chai": {
@@ -508,10 +501,13 @@
       }
     },
     "eslint-utils": {
-      "version": "1.3.1",
-      "resolved": "https://registry.npmjs.org/eslint-utils/-/eslint-utils-1.3.1.tgz",
-      "integrity": "sha512-Z7YjnIldX+2XMcjr7ZkgEsOj/bREONV60qYeB/bjMAqqqZ4zxKyWX+BOUkdmRmA9riiIPVvo5x86m5elviOk0Q==",
-      "dev": true
+      "version": "1.4.0",
+      "resolved": "https://registry.npmjs.org/eslint-utils/-/eslint-utils-1.4.0.tgz",
+      "integrity": "sha512-7ehnzPaP5IIEh1r1tkjuIrxqhNkzUJa9z3R92tLJdZIVdWaczEhr3EbhGtsMrVxi1KeR8qA7Off6SWc5WNQqyQ==",
+      "dev": true,
+      "requires": {
+        "eslint-visitor-keys": "^1.0.0"
+      }
     },
     "eslint-visitor-keys": {
       "version": "1.0.0",
@@ -587,9 +583,9 @@
       "integrity": "sha512-fjquC59cD7CyW6urNXK0FBufkZcoiGG80wTuPujX590cB5Ttln20E2UB4S/WARVqhXffZl2LNgS+gQdPIIim/g=="
     },
     "external-editor": {
-      "version": "3.0.3",
-      "resolved": "https://registry.npmjs.org/external-editor/-/external-editor-3.0.3.tgz",
-      "integrity": "sha512-bn71H9+qWoOQKyZDo25mOMVpSmXROAsTJVVVYzrrtol3d4y+AsKjf4Iwl2Q+IuT0kFSQ1qo166UuIwqYq7mGnA==",
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/external-editor/-/external-editor-3.1.0.tgz",
+      "integrity": "sha512-hMQ4CX1p1izmuLYyZqLMO/qGNw10wSv9QDCPfzXfyFrOaCSSoRfqE1Kf1s5an66J5JZC62NewG+mK49jOCtQew==",
       "dev": true,
       "requires": {
         "chardet": "^0.7.0",
@@ -885,9 +881,9 @@
       "dev": true
     },
     "inquirer": {
-      "version": "6.4.1",
-      "resolved": "https://registry.npmjs.org/inquirer/-/inquirer-6.4.1.tgz",
-      "integrity": "sha512-/Jw+qPZx4EDYsaT6uz7F4GJRNFMRdKNeUZw3ZnKV8lyuUgz/YWRCSUAJMZSVhSq4Ec0R2oYnyi6b3d4JXcL5Nw==",
+      "version": "6.5.0",
+      "resolved": "https://registry.npmjs.org/inquirer/-/inquirer-6.5.0.tgz",
+      "integrity": "sha512-scfHejeG/lVZSpvCXpsB4j/wQNPM5JC8kiElOI0OUTwmc1RTpXr4H32/HOlQHcZiYl2z2VElwuCVDRG8vFmbnA==",
       "dev": true,
       "requires": {
         "ansi-escapes": "^3.2.0",
@@ -896,7 +892,7 @@
         "cli-width": "^2.0.0",
         "external-editor": "^3.0.3",
         "figures": "^2.0.0",
-        "lodash": "^4.17.11",
+        "lodash": "^4.17.12",
         "mute-stream": "0.0.7",
         "run-async": "^2.2.0",
         "rxjs": "^6.4.0",
@@ -1661,17 +1657,6 @@
         "uuid": "^3.3.2"
       }
     },
-    "request-promise": {
-      "version": "4.2.4",
-      "resolved": "https://registry.npmjs.org/request-promise/-/request-promise-4.2.4.tgz",
-      "integrity": "sha512-8wgMrvE546PzbR5WbYxUQogUnUDfM0S7QIFZMID+J73vdFARkFy+HElj4T+MWYhpXwlLp0EQ8Zoj8xUA0he4Vg==",
-      "requires": {
-        "bluebird": "^3.5.0",
-        "request-promise-core": "1.1.2",
-        "stealthy-require": "^1.1.1",
-        "tough-cookie": "^2.3.3"
-      }
-    },
     "request-promise-core": {
       "version": "1.1.2",
       "resolved": "https://registry.npmjs.org/request-promise-core/-/request-promise-core-1.1.2.tgz",
@@ -1680,6 +1665,16 @@
         "lodash": "^4.17.11"
       }
     },
+    "request-promise-native": {
+      "version": "1.0.7",
+      "resolved": "https://registry.npmjs.org/request-promise-native/-/request-promise-native-1.0.7.tgz",
+      "integrity": "sha512-rIMnbBdgNViL37nZ1b3L/VfPOpSi0TqVDQPAvO6U14lMzOLrt5nilxCQqtDKhZeDiW0/hkCXGoQjhgJd/tCh6w==",
+      "requires": {
+        "request-promise-core": "1.1.2",
+        "stealthy-require": "^1.1.1",
+        "tough-cookie": "^2.3.3"
+      }
+    },
     "require-directory": {
       "version": "2.1.1",
       "resolved": "https://registry.npmjs.org/require-directory/-/require-directory-2.1.1.tgz",
@@ -1699,14 +1694,6 @@
       "dev": true,
       "requires": {
         "lodash": "^4.17.14"
-      },
-      "dependencies": {
-        "lodash": {
-          "version": "4.17.15",
-          "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.15.tgz",
-          "integrity": "sha512-8xOcRHvCjnocdS5cpwXQXVzmmh5e5+saE2QGoeQmbKmRS6J3VQppPOIt0MnmE+4xlZoumy0GPG0D0MVIQbNA1A==",
-          "dev": true
-        }
       }
     },
     "resolve-from": {
@@ -1874,13 +1861,13 @@
       }
     },
     "table": {
-      "version": "5.4.1",
-      "resolved": "https://registry.npmjs.org/table/-/table-5.4.1.tgz",
-      "integrity": "sha512-E6CK1/pZe2N75rGZQotFOdmzWQ1AILtgYbMAbAjvms0S1l5IDB47zG3nCnFGB/w+7nB3vKofbLXCH7HPBo864w==",
+      "version": "5.4.4",
+      "resolved": "https://registry.npmjs.org/table/-/table-5.4.4.tgz",
+      "integrity": "sha512-IIfEAUx5QlODLblLrGTTLJA7Tk0iLSGBvgY8essPRVNGHAzThujww1YqHLs6h3HfTg55h++RzLHH5Xw/rfv+mg==",
       "dev": true,
       "requires": {
-        "ajv": "^6.9.1",
-        "lodash": "^4.17.11",
+        "ajv": "^6.10.2",
+        "lodash": "^4.17.14",
         "slice-ansi": "^2.1.0",
         "string-width": "^3.0.0"
       },
diff --git a/package.json b/package.json
index 7aeb105..80d3636 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "poloniex-node-api",
-  "version": "0.3.6",
+  "version": "0.4.0",
   "description": "Poloniex Node.js API",
   "main": "index.js",
   "directories": {
@@ -36,7 +36,7 @@
   "homepage": "https://github.com/vansergen/poloniex-node-api#readme",
   "dependencies": {
     "request": "^2.88.0",
-    "request-promise": "^4.2.4",
+    "request-promise-native": "^1.0.7",
     "ws": "^7.1.1"
   },
   "devDependencies": {
diff --git a/tests/public.spec.js b/tests/public.spec.js
index ec41351..d5c1262 100644
--- a/tests/public.spec.js
+++ b/tests/public.spec.js
@@ -35,9 +35,7 @@ suite('PublicClient', () => {
       .request({ method: 'GET', url: EXCHANGE_API_URL + '/public' })
       .then(() => assert.fail('Should have thrown an error'))
       .catch(error => {
-        assert.deepEqual(error.message, '400 - {"error":"some error"}');
-        assert.deepEqual(error.statusCode, 400);
-        assert.deepEqual(error.error, data);
+        assert.deepEqual(error, data);
         done();
       });
   });
@@ -45,6 +43,7 @@ suite('PublicClient', () => {
   test('.cb()', () => {
     const response = { response: 1 };
     const options = { method: 'GET', url: EXCHANGE_API_URL + '/public' };
+    const _method = 'request';
     nock(EXCHANGE_API_URL)
       .get('/public')
       .times(2)
@@ -59,7 +58,7 @@ suite('PublicClient', () => {
           resolve(data);
         }
       };
-      publicClient.cb('request', callback, options);
+      publicClient.cb({ _method, ...options }, callback);
     });
 
     const preq = publicClient
diff --git a/tests/signer.spec.js b/tests/signer.spec.js
index 6726f69..b8b7d9b 100644
--- a/tests/signer.spec.js
+++ b/tests/signer.spec.js
@@ -1,8 +1,6 @@
 const assert = require('assert');
 
-const Poloniex = require('../index.js');
-
-const signer = Poloniex.SignRequest;
+const signer = require('../lib/signer.js');
 
 suite('SignRequest', () => {
   test('correct signature', () => {