diff --git a/.editorconfig b/.editorconfig
deleted file mode 100644
index 6f445f1..0000000
--- a/.editorconfig
+++ /dev/null
@@ -1,15 +0,0 @@
-# Install EditorConfig Plugin on your IDE for one coding style
-# EditorConfig is awesome: http://EditorConfig.org
-
-root = true
-
-[*]
-charset = utf-8
-end_of_line = lf
-insert_final_newline = true
-trim_trailing_whitespace = true
-indent_style = tab
-tab_width = 4
-[*.md]
-max_line_length = off
-trim_trailing_whitespace = false
diff --git a/.eslintrc.js b/.eslintrc.js
index 6dd62da..b349f4d 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -1,43 +1,29 @@
 module.exports = {
-    "parserOptions": {
-        "ecmaVersion": 8,
-        "sourceType": "module"
-    },
-    "rules": {
-        "semi": "warn", // обязательно ;
-        "semi-spacing": ["error", {"before": false, "after": true}],
-        "indent": ["error", "tab"],
-        "space-infix-ops": "error",// отступы вокруг + - * / = и тд
-        "eqeqeq": "error", // обязательно === и !== (нельзя == и !=)
-        // "no-eq-null": "error", // обязательно === и !== (нельзя == и !=) но тоько в отношении null
-        "curly": "error", // проверка шаблонов `${name}`
-        // "space-before-function-paren": [ // отступ до и после function
-        //     "error", {
-        //         "anonymous": "always",
-        //         "named": "always",
-        //         "asyncArrow": "ignore"
-        //     }
-        // ],
-        "key-spacing": ["error", { "mode": "strict" }], // оформление обЪекта
-        "space-in-parens": ["error", "never"], // запрет отступов ( a,b)
-        "computed-property-spacing": ["error", "never"], // запрет лишних отступов в выражениях a[ i]
-        "array-bracket-spacing": ["error", "never"],
-        "no-multi-spaces": "error", // запрет лишних пробелов var a   = 2
-        "no-sparse-arrays": "warn", // предупреждение при дырке в массиве
-        "no-mixed-spaces-and-tabs": "error", // нельзя миксовать табы и пробелы
-        "keyword-spacing": ["error", { "after": true }],
-        "comma-spacing": ["error", { "before": false, "after": true }], // отступ после запятой, а перед нельзя
-        "no-undef":"error",
-        "array-callback-return": "error" // коллбек методов массива типа arr.map arr.filter должны иметь return в коллбеке
-    },
-    "env": {
-        "browser": true,
-        "node": true
-    },
-    "globals": {
-        "Vue":true,
-        "Symbol":true,
-        "Promise":true,
-    },
-    "plugins": []
-}
+  env: {
+    commonjs: true,
+    es2021: true,
+    browser: true,
+    node: true,
+    'jest/globals': true,
+  },
+  extends: ['eslint:recommended', 'google'],
+  plugins: ['jest'],
+  parserOptions: {
+    ecmaVersion: 12,
+  },
+  rules: {
+    'max-len': [
+      'error',
+      {
+        code: 200,
+        ignoreTrailingComments: true,
+        ignoreUrls: true,
+        ignoreStrings: true,
+        ignoreTemplateLiterals: true,
+        ignoreRegExpLiterals: true,
+      },
+    ],
+    'require-jsdoc': 'off',
+    'quote-props': 'off',
+  },
+};
diff --git a/.gitignore b/.gitignore
index f081cae..977a377 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,4 @@ logs/
 .vscode/
 test.js
 package-lock.json
+.editorconfig
diff --git a/.husky/commit-msg b/.husky/commit-msg
new file mode 100755
index 0000000..7fed485
--- /dev/null
+++ b/.husky/commit-msg
@@ -0,0 +1,4 @@
+#!/bin/sh
+. "$(dirname "$0")/_/husky.sh"
+
+npx --no -- commitlint --edit 
diff --git a/.husky/pre-commit b/.husky/pre-commit
new file mode 100755
index 0000000..20d0d06
--- /dev/null
+++ b/.husky/pre-commit
@@ -0,0 +1,4 @@
+#!/bin/sh
+. "$(dirname "$0")/_/husky.sh"
+
+npm run lint
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000..f45a23b
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,91 @@
+# Contributing Guide
+
+Before submitting your contribution, please make sure to take a moment and read through the following guidelines:
+
+- [Pull Request Guidelines](#pull-request-guidelines)
+- [Development Setup](#development-setup)
+- [Scripts](#scripts)
+- [Project Structure](#project-structure)
+- [Contributing Tests](#contributing-tests)
+
+## Pull Request Guidelines
+
+- The master branch is just a snapshot of the latest stable release. All development should be done in dedicated branches. Do not submit PRs against the master branch.
+
+- Checkout a topic branch from a base branch, e.g. `master`, and merge back against that branch.
+
+- If adding a new feature add accompanying test case.
+
+- It's OK to have multiple small commits as you work on the PR - GitHub can automatically squash them before merging.
+
+- Make sure tests pass!
+
+- Commit messages must follow the [commit message convention](./commit-convention.md). Commit messages are automatically validated before commit (by invoking [Git Hooks](https://git-scm.com/docs/githooks) via [husky](https://github.com/typicode/husky)).
+
+- No need to worry about code style as long as you have installed the dev dependencies - modified files are automatically formatted with Prettier on commit (by invoking [Git Hooks](https://git-scm.com/docs/githooks) via [husky](https://github.com/typicode/husky)).
+
+## Development Setup
+
+You will need [Node.js](https://nodejs.org) **version 16+**.
+
+After cloning the repo, run:
+
+```bash
+$ npm i # install the dependencies of the project
+```
+
+A high level overview of tools used:
+
+- [Jest](https://jestjs.io/) for unit testing
+- [Prettier](https://prettier.io/) for code formatting
+
+## Scripts
+
+### `npm run lint`
+
+The `lint` script runs linter.
+
+```bash
+# lint files
+$ npm run lint
+# fix linter errors
+$ npm run lint:fix
+```
+
+### `npm run test`
+
+The `test` script simply calls the `jest` binary, so all [Jest CLI Options](https://jestjs.io/docs/en/cli) can be used. Some examples:
+
+```bash
+# run all tests
+$ npm run test
+
+# run all tests under the runtime-core package
+$ npm run test -- runtime-core
+
+# run tests in a specific file
+$ npm run test -- fileName
+
+# run a specific test in a specific file
+$ npm run test -- fileName -t 'test name'
+```
+
+## Project Structure
+
+- **`src`**: contains the source code
+
+  - **`api`**: contains group of methods and methods for the API.
+
+  - **`helpers`**: contains utilities shared across the entire codebase.
+
+    - **`tests`**: contains tests for the helpers directory.
+
+  - **`tests`**: contains tests for the src directory.
+
+## Contributing Tests
+
+Unit tests are collocated with the code being tested inside directories named `tests`. Consult the [Jest docs](https://jestjs.io/docs/en/using-matchers) and existing test cases for how to write new test specs. Here are some additional guidelines:
+
+- Use the minimal API needed for a test case. For example, if a test can be written without involving the reactivity system or a component, it should be written so. This limits the test's exposure to changes in unrelated parts and makes it more stable.
+
+- Only use platform-specific runtimes if the test is asserting platform-specific behavior.
diff --git a/commitlint.config.js b/commitlint.config.js
new file mode 100644
index 0000000..c34aa79
--- /dev/null
+++ b/commitlint.config.js
@@ -0,0 +1,3 @@
+module.exports = {
+  extends: ['@commitlint/config-conventional']
+};
diff --git a/groups/decodeMsg.js b/groups/decodeMsg.js
deleted file mode 100644
index 31829bb..0000000
--- a/groups/decodeMsg.js
+++ /dev/null
@@ -1,83 +0,0 @@
-const ed2curve = require('ed2curve');
-const nacl = require('tweetnacl/nacl-fast');
-const keys = require('../helpers/keys');
-
-module.exports = (msg, senderPublicKey, passPhrase, nonce) => {
-
-	const keypair = keys.createKeypairFromPassPhrase(passPhrase);
-	let privateKey = keypair.privateKey;
-	if (typeof msg === 'string') {
-		msg = hexToBytes(msg)
-	}
-	if (typeof nonce === 'string') {
-		nonce = hexToBytes(nonce)
-	}
-
-	if (typeof senderPublicKey === 'string') {
-		senderPublicKey = hexToBytes(senderPublicKey)
-	}
-
-	if (typeof privateKey === 'string') {
-		privateKey = hexToBytes(privateKey)
-	}
-	const DHPublicKey = ed2curve.convertPublicKey(senderPublicKey);
-	const DHSecretKey = ed2curve.convertSecretKey(privateKey);
-	const decrypted = nacl.box.open(msg, nonce, DHPublicKey, DHSecretKey);
-	return decrypted ? Utf8ArrayToStr(decrypted) : ''
-
-}
-
-function hexToBytes(hexString = '') {
-
-	const bytes = []
-
-	for (let c = 0; c < hexString.length; c += 2) {
-		bytes.push(parseInt(hexString.substr(c, 2), 16))
-	}
-
-	return Uint8Array.from(bytes);
-
-}
-
-function Utf8ArrayToStr(array) {
-
-	var out, i, len, c;
-	var char2, char3;
-
-	out = "";
-	len = array.length;
-	i = 0;
-	while (i < len) {
-		c = array[i++];
-		switch (c >> 4) {
-			case 0:
-			case 1:
-			case 2:
-			case 3:
-			case 4:
-			case 5:
-			case 6:
-			case 7:
-				// 0xxxxxxx
-				out += String.fromCharCode(c);
-				break;
-			case 12:
-			case 13:
-				// 110x xxxx   10xx xxxx
-				char2 = array[i++];
-				out += String.fromCharCode(((c & 0x1F) << 6) | (char2 & 0x3F));
-				break;
-			case 14:
-				// 1110 xxxx  10xx xxxx  10xx xxxx
-				char2 = array[i++];
-				char3 = array[i++];
-				out += String.fromCharCode(((c & 0x0F) << 12) |
-					((char2 & 0x3F) << 6) |
-					((char3 & 0x3F) << 0));
-				break;
-		}
-	}
-
-	return out;
-
-}
\ No newline at end of file
diff --git a/groups/eth.js b/groups/eth.js
deleted file mode 100644
index a8b086f..0000000
--- a/groups/eth.js
+++ /dev/null
@@ -1,24 +0,0 @@
-var Mnemonic = require('bitcore-mnemonic');
-const hdkey = require('hdkey');
-const HD_KEY_PATH = "m/44'/60'/3'/1/0";
-const { bufferToHex, privateToAddress } = require('ethereumjs-util');
-const eth = { }
-
-/**
- * Generates a ETH account from the passphrase specified.
- * @param {string} passphrase ADAMANT account passphrase
- * @returns {{address: String, privateKey: Buffer}}
- */
-
-eth.keys = passphrase => {
-	const mnemonic = new Mnemonic(passphrase, Mnemonic.Words.ENGLISH);
-	const seed = mnemonic.toSeed();
-	const privateKey = hdkey.fromMasterSeed(seed).derive(HD_KEY_PATH)._privateKey;
-
-	return {
-		address: bufferToHex(privateToAddress(privateKey)),
-		privateKey: bufferToHex(privateKey)
-	};
-};
-
-module.exports = eth;
diff --git a/groups/get.js b/groups/get.js
deleted file mode 100644
index 507c522..0000000
--- a/groups/get.js
+++ /dev/null
@@ -1,46 +0,0 @@
-const axios = require('axios');
-const logger = require('../helpers/logger');
-const validator = require('../helpers/validator');
-
-const DEFAULT_GET_REQUEST_RETRIES = 3; // How much re-tries for get-requests by default. Total 3+1 tries
-
-module.exports = (nodeManager) => {
-	return (endpoint, params, maxRetries = DEFAULT_GET_REQUEST_RETRIES, retryNo = 0) => {
-
-		let url = trimAny(endpoint, "/ ").replace(/^api\//, '');
-		if (!url || !validator.validateEndpoint(endpoint))
-			  return validator.badParameter('endpoint')
-
-    url = nodeManager.node() + '/api/' + url;
-    return axios.get(url, { params })
-      .then(function (response) {
-        return validator.formatRequestResults(response, true)
-      })
-      .catch(function (error) {
-				let logMessage = `[ADAMANT js-api] Get-request: Request to ${url} failed with ${error.response ? error.response.status : undefined} status code, ${error.toString()}${error.response && error.response.data ? '. Message: ' + error.response.data.toString().trim() : ''}. Try ${retryNo+1} of ${maxRetries+1}.`;
-				if (retryNo < maxRetries) {
-					logger.log(`${logMessage} Retrying…`);
-					return nodeManager.changeNodes()
-						.then(function () {
-							return module.exports(nodeManager)(endpoint, params, maxRetries, ++retryNo)
-						})
-				}
-				logger.warn(`${logMessage} No more attempts, returning error.`);
-        return validator.formatRequestResults(error, false)
-      })
-
-  }
-};
-
-function trimAny(str, chars) {
-	if (!str || typeof str !== 'string')
-		return ''
-	let start = 0, 
-		end = str.length;
-	while(start < end && chars.indexOf(str[start]) >= 0)
-		++start;
-	while(end > start && chars.indexOf(str[end - 1]) >= 0)
-		--end;
-	return (start > 0 || end < str.length) ? str.substring(start, end) : str;
-}
-
diff --git a/groups/sendMessage.js b/groups/sendMessage.js
deleted file mode 100644
index 991628c..0000000
--- a/groups/sendMessage.js
+++ /dev/null
@@ -1,143 +0,0 @@
-const axios = require('axios');
-const logger = require('../helpers/logger');
-const keys = require('../helpers/keys');
-const constants = require('../helpers/constants');
-const encryptor = require('../helpers/encryptor');
-const transactionFormer = require('../helpers/transactionFormer');
-const validator = require('../helpers/validator');
-const getPublicKey = require('./getPublicKey');
-
-const DEFAULT_SEND_MESSAGE_RETRIES = 4; // How much re-tries for send message requests by default. Total 4+1 tries
-
-module.exports = (nodeManager) => {
-  /**
-		* Encrypts a message, creates Message transaction, signs it, and broadcasts to ADAMANT network. Supports Basic, Rich and Signal Message Types.
-    * See https://github.com/Adamant-im/adamant/wiki/Message-Types
-    * @param {string} passPhrase Senders's passPhrase. Sender's address will be derived from it.
-    * @param {string} addressOrPublicKey Recipient's ADAMANT address or public key.
-    * Using public key is faster, as the library wouldn't request it from the network.
-    * Though we cache public keys, and next request with address will be processed as fast as with public key.
-    * @param {string} message Message plain text in case of basic message. Stringified JSON in case of rich or signal messages. The library will encrypt a message.
-    * Example of rich message for Ether in-chat transfer: `{"type":"eth_transaction","amount":"0.002","hash":"0xfa46d2b3c99878f1f9863fcbdb0bc27d220d7065c6528543cbb83ced84487deb","comments":"I like to send it, send it"}`
-    * @param {string, number} message_type Type of message: basic, rich, or signal
-    * @param {string, number} amount Amount to send with a message
-    * @param {boolean} isAmountInADM If amount specified in ADM, or in sats (10^-8 ADM)
-    * @param {number} maxRetries How much times to retry request
-    * @returns {Promise} Request results
-  	*/
-	return async (passPhrase, addressOrPublicKey, message, message_type = 'basic', amount, isAmountInADM = true, maxRetries = DEFAULT_SEND_MESSAGE_RETRIES, retryNo = 0) => {
-
-    let keyPair, data;
-    let address, publicKey;
-
-    try {
-
-      if (!validator.validatePassPhrase(passPhrase))
-			  return validator.badParameter('passPhrase')
-    
-      keyPair = keys.createKeypairFromPassPhrase(passPhrase);
-
-      if (!validator.validateAdmAddress(addressOrPublicKey)) {
-        if (!validator.validateAdmPublicKey(addressOrPublicKey)) {
-          return validator.badParameter('addressOrPublicKey', addressOrPublicKey)
-        } else {
-          publicKey = addressOrPublicKey;
-          try {
-            address = keys.createAddressFromPublicKey(publicKey)
-          } catch (e) {
-            return validator.badParameter('addressOrPublicKey', addressOrPublicKey)
-          }
-        }
-      } else {
-        publicKey = '';
-        address = addressOrPublicKey
-      }
-
-      if (message_type === 'basic')
-        message_type = 1;
-      if (message_type === 'rich')
-        message_type = 2;
-      if (message_type === 'signal')
-        message_type = 3;
-        
-      if (!validator.validateMessageType(message_type))
-        return validator.badParameter('message_type', message_type)
-
-      let messageValidation = validator.validateMessage(message, message_type);
-      if (!messageValidation.result)
-        return validator.badParameter('message', message, messageValidation.error)
-
-      data = {
-        keyPair,
-        recipientId: address,
-        message_type
-      };
-  
-      if (amount) {
-        if (isAmountInADM) {
-          amountInSat = validator.AdmToSats(amount)
-        } else {
-          amountInSat = amount
-        }  
-        if (!validator.validateIntegerAmount(amountInSat))
-          return validator.badParameter('amount', amount)
-        data.amount = amountInSat;
-      }
-
-    } catch (e) {
-
-      return validator.badParameter('#exception_catched#', e)
-
-    }
-
-    if (!publicKey)
-      publicKey = await getPublicKey(nodeManager)(address);
-
-    if (!publicKey)
-      return new Promise((resolve, reject) => {
-        resolve({
-          success: false,
-          errorMessage: `Unable to get public key for ${addressOrPublicKey}. It is necessary for sending an encrypted message. Account may be uninitialized (https://medium.com/adamant-im/chats-and-uninitialized-accounts-in-adamant-5035438e2fcd), or network error`
-        })
-      })
-
-    try {
-
-      const encryptedMessage = encryptor.encodeMessage(message, keyPair, publicKey);
-      data.message = encryptedMessage.message;
-      data.own_message = encryptedMessage.own_message;
-
-      let transaction = transactionFormer.createTransaction(constants.transactionTypes.CHAT_MESSAGE, data);
-
-      let url = nodeManager.node() + '/api/transactions/process';
-      return axios.post(url, { transaction })
-        .then(function (response) {
-          return validator.formatRequestResults(response, true)
-        })
-        .catch(function (error) {
-          let logMessage = `[ADAMANT js-api] Send message request: Request to ${url} failed with ${error.response ? error.response.status : undefined} status code, ${error.toString()}${error.response && error.response.data ? '. Message: ' + error.response.data.toString().trim() : ''}. Try ${retryNo+1} of ${maxRetries+1}.`;
-          if (retryNo < maxRetries) {
-            logger.log(`${logMessage} Retrying…`);
-            return nodeManager.changeNodes()
-              .then(function () {
-                return module.exports(nodeManager)(passPhrase, addressOrPublicKey, message, message_type, tokensAmount, maxRetries, ++retryNo)
-              })
-          }
-          logger.warn(`${logMessage} No more attempts, returning error.`);
-          return validator.formatRequestResults(error, false)
-        })
-        
-    } catch (e) {
-
-      return new Promise((resolve, reject) => {
-        resolve({
-          success: false,
-          errorMessage: `Unable to encode message '${message}' with public key ${publicKey}, or unable to build a transaction. Exception: ` + e
-        })
-      })
-
-    }
-
-  } // sendMessage()
-
-};
diff --git a/groups/sendTokens.js b/groups/sendTokens.js
deleted file mode 100644
index 6e5da0d..0000000
--- a/groups/sendTokens.js
+++ /dev/null
@@ -1,92 +0,0 @@
-const axios = require('axios');
-const logger = require('../helpers/logger');
-const keys = require('../helpers/keys');
-const constants = require('../helpers/constants');
-const transactionFormer = require('../helpers/transactionFormer');
-const validator = require('../helpers/validator');
-
-const DEFAULT_SEND_TOKENS_RETRIES = 4; // How much re-tries for send tokens requests by default. Total 4+1 tries
-
-module.exports = (nodeManager) => {
-  /**
-		* Creates Token Transfer transaction, signs it, and broadcasts to ADAMANT network
-    * See https://github.com/Adamant-im/adamant/wiki/Transaction-Types#type-0-token-transfer-transaction
-    * @param {string} passPhrase Senders's passPhrase. Sender's address will be derived from it.
-    * @param {string} addressOrPublicKey Recipient's ADAMANT address or public key.
-    * Address is preferred, as if we get public key, we should derive address from it.
-    * @param {string, number} amount Amount to send
-    * @param {boolean} isAmountInADM If amount specified in ADM, or in sats (10^-8 ADM)
-    * @param {number} maxRetries How much times to retry request
-    * @returns {Promise} Request results
-  	*/
-	return (passPhrase, addressOrPublicKey, amount, isAmountInADM = true, maxRetries = DEFAULT_SEND_TOKENS_RETRIES, retryNo = 0) => {
-
-    let transaction;
-    let address, publicKey;
-
-    try {
-
-      if (!validator.validatePassPhrase(passPhrase))
-			  return validator.badParameter('passPhrase')
-    
-      const keyPair = keys.createKeypairFromPassPhrase(passPhrase);
-
-      if (!validator.validateAdmAddress(addressOrPublicKey)) {
-        if (!validator.validateAdmPublicKey(addressOrPublicKey)) {
-          return validator.badParameter('addressOrPublicKey', addressOrPublicKey)
-        } else {
-          publicKey = addressOrPublicKey;
-          try {
-            address = keys.createAddressFromPublicKey(publicKey)
-          } catch (e) {
-            return validator.badParameter('addressOrPublicKey', addressOrPublicKey)
-          }
-        }
-      } else {
-        publicKey = '';
-        address = addressOrPublicKey
-      }
-      
-      if (isAmountInADM) {
-        amountInSat = validator.AdmToSats(amount)
-      } else {
-        amountInSat = amount
-      }
-
-      if (!validator.validateIntegerAmount(amountInSat))
-        return validator.badParameter('amount', amount)
-
-      const data = {
-        keyPair,
-        recipientId: address,
-        amount: amountInSat
-      };
-
-      transaction = transactionFormer.createTransaction(constants.transactionTypes.SEND, data);
-
-    } catch (e) {
-
-      return validator.badParameter('#exception_catched#', e)
-
-    }
-
-    let url = nodeManager.node() + '/api/transactions/process';
-    return axios.post(url, { transaction })
-      .then(function (response) {
-        return validator.formatRequestResults(response, true)
-      })
-      .catch(function (error) {
-				let logMessage = `[ADAMANT js-api] Send tokens request: Request to ${url} failed with ${error.response ? error.response.status : undefined} status code, ${error.toString()}${error.response && error.response.data ? '. Message: ' + error.response.data.toString().trim() : ''}. Try ${retryNo+1} of ${maxRetries+1}.`;
-				if (retryNo < maxRetries) {
-					logger.log(`${logMessage} Retrying…`);
-					return nodeManager.changeNodes()
-						.then(function () {
-							return module.exports(nodeManager)(passPhrase, addressOrPublicKey, amount, isAmountInADM, maxRetries, ++retryNo)
-						})
-				}
-				logger.warn(`${logMessage} No more attempts, returning error.`);
-        return validator.formatRequestResults(error, false)
-      })
-
-  }
-};
diff --git a/helpers/bignumber.js b/helpers/bignumber.js
deleted file mode 100644
index c6b556d..0000000
--- a/helpers/bignumber.js
+++ /dev/null
@@ -1,119 +0,0 @@
-/* eslint-disable no-redeclare */
-'use strict'
-
-/**
-	* Buffer functions that implements bignumber.
-	* @memberof module:helpers
-	* @requires bignumber
-	* @constructor
-*/
-var BigNumber = require('bignumber.js')
-
-/**
-	* Creates an instance from a Buffer.
-	* @param {ArrayBuffer} buf
-	* @param {Object} opts
-	* @return {ArrayBuffer} new BigNumber instance
-	* @throws {RangeError} error description multiple of size
-*/
-BigNumber.fromBuffer = function (buf, opts) {
-	if (!opts) opts = {}
-	
-	var endian = { 1: 'big', '-1': 'little' }[opts.endian] || opts.endian || 'big'
-	
-	var size = opts.size === 'auto' ? Math.ceil(buf.length) : (opts.size || 1)
-	
-	if (buf.length % size !== 0) {
-		throw new RangeError('Buffer length (' + buf.length + ')' +
-		' must be a multiple of size (' + size + ')'
-		)
-	}
-	
-	var hex = []
-	for (var i = 0; i < buf.length; i += size) {
-		var chunk = []
-		for (var j = 0; j < size; j++) {
-			chunk.push(buf[i + (endian === 'big' ? j : (size - j - 1))])
-		}
-		
-		hex.push(chunk
-		.map(function (c) {
-			return (c < 16 ? '0' : '') + c.toString(16)
-		})
-		.join('')
-		)
-	}
-	
-	return new BigNumber(hex.join(''), 16)
-}
-
-/**
-	* Returns an instance as Buffer.
-	* @param {Object} opts
-	* @return {ArrayBuffer} new buffer | error message invalid option
-*/
-BigNumber.prototype.toBuffer = function (opts) {
-	if (typeof opts === 'string') {
-		if (opts !== 'mpint') return 'Unsupported Buffer representation'
-		
-		var abs = this.abs()
-		var buf = abs.toBuffer({ size: 1, endian: 'big' })
-		var len = buf.length === 1 && buf[0] === 0 ? 0 : buf.length
-		if (buf[0] & 0x80) len++
-		
-		var ret = Buffer.alloc(4 + len)
-		if (len > 0) buf.copy(ret, 4 + (buf[0] & 0x80 ? 1 : 0))
-		if (buf[0] & 0x80) ret[4] = 0
-		
-		ret[0] = len & (0xff << 24)
-		ret[1] = len & (0xff << 16)
-		ret[2] = len & (0xff << 8)
-		ret[3] = len & (0xff << 0)
-		
-		// Two's compliment for negative integers
-		var isNeg = this.lt(0)
-		if (isNeg) {
-			for (var i = 4; i < ret.length; i++) {
-				ret[i] = 0xff - ret[i]
-			}
-		}
-		ret[4] = (ret[4] & 0x7f) | (isNeg ? 0x80 : 0)
-		if (isNeg) ret[ret.length - 1] ++
-		
-		return ret
-	}
-	
-	if (!opts) opts = {}
-	
-	var endian = { 1: 'big', '-1': 'little' }[opts.endian] || opts.endian || 'big'
-	
-	var hex = this.toString(16)
-	if (hex.charAt(0) === '-') {
-		throw new Error(
-		'Converting negative numbers to Buffers not supported yet'
-		)
-	}
-	
-	var size = opts.size === 'auto' ? Math.ceil(hex.length / 2) : (opts.size || 1)
-	
-	var len = Math.ceil(hex.length / (2 * size)) * size
-	var buf = Buffer.alloc(len)
-	
-	// Zero-pad the hex string so the chunks are all `size` long
-	while (hex.length < 2 * len) hex = '0' + hex
-	
-	var hx = hex
-	.split(new RegExp('(.{' + (2 * size) + '})'))
-	.filter(function (s) { return s.length > 0 })
-	
-	hx.forEach(function (chunk, i) {
-		for (var j = 0; j < size; j++) {
-			var ix = i * size + (endian === 'big' ? j : size - j - 1)
-			buf[ix] = parseInt(chunk.slice(j * 2, j * 2 + 2), 16)
-		}
-	})
-	
-	return buf
-}
-
-module.exports = BigNumber
diff --git a/helpers/constants.js b/helpers/constants.js
deleted file mode 100644
index bee5c31..0000000
--- a/helpers/constants.js
+++ /dev/null
@@ -1,43 +0,0 @@
-module.exports = {
-
-	epochTime: new Date(Date.UTC(2017, 8, 2, 17, 0, 0, 0)),
-	fees: {
-		send: 50000000,
-		vote: 1000000000,
-		secondsignature: 500000000,
-		delegate: 30000000000,
-		multisignature: 500000000,
-		dapp: 2500000000,
-		old_chat_message: 500000,
-		chat_message: 100000,
-		profile_update: 5000000,
-		avatar_upload: 10000000,
-		state_store: 100000
-	},
-	transactionTypes: {
-		SEND: 0,
-		SIGNATURE: 1,
-		DELEGATE: 2,
-		VOTE: 3,
-		MULTI: 4,
-		DAPP: 5,
-		IN_TRANSFER: 6,
-		OUT_TRANSFER: 7,
-		CHAT_MESSAGE: 8,
-		STATE: 9
-	},
-	maxVotesPerTransaction: 33,
-	SAT: 100000000,
-	RE_HEX: /^[a-fA-F0-9]+$/,
-	RE_BASE64: /^([A-Za-z0-9+/]{4})*([A-Za-z0-9+/]{4}|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{2}==)$/,
-	RE_ADM_ADDRESS: /^U([0-9]{6,})$/,
-	RE_ADM_VOTE_FOR_PUBLIC_KEY: /^(\+|-)[a-fA-F0-9]{64}$/,
-	RE_ADM_VOTE_FOR_ADDRESS: /^(\+|-)U([0-9]{6,})$/,
-	RE_ADM_VOTE_FOR_DELEGATE_NAME: /^(\+|-)([a-z0-9!@$&_]{1,20})$/,
-	RE_ADM_DELEGATE_NAME: /^[a-z0-9!@$&_]{1,20}$/,
-	RE_BTC_ADDRESS: /^(bc1|[13])[a-km-zA-HJ-NP-Z02-9]{25,39}$/,
-	RE_DASH_ADDRESS: /^[7X][1-9A-HJ-NP-Za-km-z]{33,}$/,
-	RE_DOGE_ADDRESS: /^[A|D|9][A-Z0-9]([0-9a-zA-Z]{9,})$/,
-	RE_LSK_ADDRESS: /^[0-9]{2,21}L$/
-
-}
diff --git a/helpers/encryptor.js b/helpers/encryptor.js
deleted file mode 100644
index fe5e4cf..0000000
--- a/helpers/encryptor.js
+++ /dev/null
@@ -1,35 +0,0 @@
-var sodium = require('sodium-browserify-tweetnacl')
-var nacl = require('tweetnacl/nacl-fast')
-var ed2curve = require('ed2curve')
-
-module.exports = {
-
-	bytesToHex: function (bytes) {
-		for (var hex = [], i = 0; i < bytes.length; i++) {
-			hex.push((bytes[i] >>> 4).toString(16))
-			hex.push((bytes[i] & 0xF).toString(16))
-		}
-		return hex.join('')
-	},
-
-	hexToBytes: function (hex) {
-		for (var bytes = [], c = 0; c < hex.length; c += 2) {
-			bytes.push(parseInt(hex.substr(c, 2), 16))
-		}
-		return bytes
-	},
-	
-	encodeMessage: function (msg, keypair, recipientPublicKey) {
-		var nonce = Buffer.allocUnsafe(24)
-		sodium.randombytes(nonce)
-		var plainText = Buffer.from(msg.toString())
-		var DHPublicKey = ed2curve.convertPublicKey(new Uint8Array(this.hexToBytes(recipientPublicKey)))
-		var DHSecretKey = ed2curve.convertSecretKey(keypair.privateKey)
-		var encrypted = nacl.box(plainText, nonce, DHPublicKey, DHSecretKey)
-		return {
-			message: this.bytesToHex(encrypted),
-			own_message: this.bytesToHex(nonce)
-		}
-	}
-
-}
diff --git a/helpers/healthCheck.js b/helpers/healthCheck.js
deleted file mode 100644
index 71b57e7..0000000
--- a/helpers/healthCheck.js
+++ /dev/null
@@ -1,198 +0,0 @@
-const axios = require('axios');
-const socket = require('./wsClient');
-const logger = require('./logger');
-const validator = require('./validator');
-const dnsPromises = require('dns').promises;
-
-const CHECK_NODES_INTERVAL = 60 * 5 * 1000; // Update active nodes every 5 minutes
-const HEIGHT_EPSILON = 5; // Used to group nodes by height and choose synced
-
-module.exports = (nodes) => {
-
-	isCheckingNodes = false;
-	nodesList = nodes;
-	activeNode = nodesList[0]; // Note: it may be not synced; and before first health check a node can reply with obsolete data
-	liveNodes = [];
-
-	/**
-		* Updates active nodes. If nodes are already updating, returns Promise of previous call
-    * @returns {Promise} Call changeNodes().then to do something when update complete
-  	*/
-	function changeNodes (isPlannedUpdate = false) {
-		if (!isCheckingNodes) {
-			changeNodesPromise = new Promise(async (resolve) => {
-				if (!isPlannedUpdate) {
-					logger.warn('[ADAMANT js-api] Health check: Forcing to update active nodes…');
-				}
-				await checkNodes(isPlannedUpdate? false : true)
-				resolve(true)
-			});
-		}
-		return changeNodesPromise
-	}
-
-	changeNodes(true)
-	setInterval(() => { changeNodes(true)	}, CHECK_NODES_INTERVAL);
-
-	return {
-
-		/**
-     * @returns {string} Current active node, f. e. http://88.198.156.44:36666
-     */
-		node: () => {
-			return activeNode;
-		},
-
-		changeNodes
-
-	};
-
-};
-
-/**
-	* Requests every ADAMANT node for its status, makes a list of live nodes, and chooses one active
-	*/
-async function checkNodes(forceChangeActiveNode) {
-
-	this.isCheckingNodes = true;
-	this.liveNodes = [];
-
-	try {
-
-		for (const n of this.nodesList) {
-			try {
-				let start = unixTimestamp();
-				let req = await checkNode(n + '/api/node/status');
-				let url = n.replace(/^https?:\/\/(.*)$/, '$1').split(":")[0];
-				let ifIP = /(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}/.test(url)
-
-				if (req.status) {
-					this.liveNodes.push({
-						node: n,
-						ifHttps: n.startsWith("https"),
-						ifIP,
-						url,
-						outOfSync: false,
-						ping: unixTimestamp() - start,
-						height: req.status.network.height,
-						heightEpsilon: Math.round(req.status.network.height / HEIGHT_EPSILON),
-						ip: ifIP ? url : await getIP(url),
-						socketSupport: req.status.wsClient && req.status.wsClient.enabled,
-						wsPort: req.status.wsClient.port
-					});
-
-				} else {
-					logger.log(`[ADAMANT js-api] Health check: Node ${n} haven't returned its status`);
-				}
-
-			} catch (e) {
-				logger.log(`[ADAMANT js-api] Health check: Error while checking node ${n}, ` + e);
-			}
-		}
-
-		const count = this.liveNodes.length;
-		let outOfSyncCount = 0;
-
-		if (!count) {
-			logger.error(`[ADAMANT js-api] Health check: All of ${this.nodesList.length} nodes are unavailable. Check internet connection and nodes list in config.`);
-		} else {
-
-			// Set activeNode to one that have maximum height and minimum ping
-			if (count === 1) {
-
-				this.activeNode = this.liveNodes[0].node;
-
-			} else if (count === 2) {
-
-				const h0 = this.liveNodes[0];
-				const h1 = this.liveNodes[1];
-				this.activeNode = h0.height > h1.height ? h0.node : h1.node;
-				// Mark node outOfSync if needed
-				if (h0.heightEpsilon > h1.heightEpsilon) {
-					this.liveNodes[1].outOfSync = true
-					outOfSyncCount += 1;
-				} else if (h0.heightEpsilon < h1.heightEpsilon) {
-					this.liveNodes[0].outOfSync = true
-					outOfSyncCount += 1;
-				}
-
-			} else {
-
-				let biggestGroup = [];
-				// Removing lodash: const groups = _.groupBy(this.liveNodes, n => n.heightEpsilon);
-				const groups = this.liveNodes.reduce(function (grouped, node) {
-					var int = Math.floor(node.heightEpsilon); // Excessive, it is already rounded
-					if (!grouped.hasOwnProperty(int)) {
-						grouped[int] = [];
-					}
-					grouped[int].push(node);
-					return grouped;
-				}, {});
-
-				Object.keys(groups).forEach(key => {
-					if (groups[key].length > biggestGroup.length) {
-						biggestGroup = groups[key];
-					}
-				});
-
-				// All the nodes from the biggestGroup list are considered to be in sync, all the others are not
-				this.liveNodes.forEach(node => {
-					node.outOfSync = !biggestGroup.includes(node)
-				})
-				outOfSyncCount = this.liveNodes.length - biggestGroup.length;
-
-				biggestGroup.sort((a, b) => a.ping - b.ping);
-				this.liveNodes.sort((a, b) => a.ping - b.ping);
-
-				if (forceChangeActiveNode && biggestGroup.length > 1 && this.activeNode === biggestGroup[0].node)
-					this.activeNode = biggestGroup[validator.getRandomIntInclusive(1, biggestGroup.length-1)].node // Use random node from which are synced
-				else
-					this.activeNode = biggestGroup[0].node; // Use node with minimum ping among which are synced
-			
-			}
-			socket.reviseConnection(this.liveNodes);
-			let unavailableCount = this.nodesList.length - this.liveNodes.length;
-			let supportedCount = this.liveNodes.length - outOfSyncCount;
-			let nodesInfoString = '';
-			if (unavailableCount)
-				nodesInfoString += `, ${unavailableCount} nodes didn't respond`
-			if (outOfSyncCount)
-				nodesInfoString += `, ${outOfSyncCount} nodes are not synced`
-			logger.log(`[ADAMANT js-api] Health check: Found ${supportedCount} supported and synced nodes${nodesInfoString}. Active node is ${this.activeNode}.`);
-			
-		}
-
-	} catch (e) {
-		logger.warn('[ADAMANT js-api] Health check: Error in checkNodes(), ' + e);
-	}
-
-	this.isCheckingNodes = false;
-
-}
-
-async function getIP(url) {
-	try {
-		let addresses = await dnsPromises.resolve4(url);
-		if (addresses && addresses[0] !== '0.0.0.0')
-			return addresses[0]
-	} catch (e) { }
-};
-
-/**
-	* Requests status from a single ADAMANT node
-	* @param url {string} Node URL to request
-	* @returns {Promise} Node's status information
-	*/
-function checkNode(url) {
-	return axios.get(url)
-		.then(function (response) {
-			return { status: response.data }
-		})
-		.catch(function (error) {
-			return false
-		})
-};
-
-function unixTimestamp() {
-	return new Date().getTime();
-}
diff --git a/helpers/keys.js b/helpers/keys.js
deleted file mode 100644
index 0e2b317..0000000
--- a/helpers/keys.js
+++ /dev/null
@@ -1,39 +0,0 @@
-var sodium = require('sodium-browserify-tweetnacl');
-var crypto = require('crypto');
-var Mnemonic = require('bitcore-mnemonic');
-var bignum = require('./bignumber.js');
-
-module.exports = {
-
-	createNewPassPhrase: function () {
-		return new Mnemonic(Mnemonic.Words.ENGLISH).toString();
-	},
-
-	makeKeypairFromHash: function (hash) {
-		var keypair = sodium.crypto_sign_seed_keypair(hash);
-		return {
-			publicKey: keypair.publicKey,
-			privateKey: keypair.secretKey
-		};
-	},
-
-	createHashFromPassPhrase: function (passPhrase) {
-		var secretMnemonic = new Mnemonic(passPhrase, Mnemonic.Words.ENGLISH);
-		return crypto.createHash('sha256').update(secretMnemonic.toSeed().toString('hex'), 'hex').digest();
-	},
-
-	createKeypairFromPassPhrase: function (passPhrase) {
-		var hash = this.createHashFromPassPhrase(passPhrase);
-		return this.makeKeypairFromHash(hash);
-	},
-
-	createAddressFromPublicKey: function (publicKey) {
-		var publicKeyHash = crypto.createHash('sha256').update(publicKey, 'hex').digest();
-		var temp = Buffer.alloc(8);
-		for (var i = 0; i < 8; i++) {
-			temp[i] = publicKeyHash[7 - i];
-		}
-		return 'U' + bignum.fromBuffer(temp).toString();
-	}
-
-}
diff --git a/helpers/logger.js b/helpers/logger.js
deleted file mode 100644
index 43ca552..0000000
--- a/helpers/logger.js
+++ /dev/null
@@ -1,35 +0,0 @@
-let logger = {
-
-	errorLevel: 'log',
-	l: console,
-
-	initLogger(errorLevel, log) {
-		if (errorLevel)
-			this.errorLevel = errorLevel;
-		if (log)
-			this.l = log;
-	},
-
-	error(str) {
-		if (['error', 'warn', 'info', 'log'].includes(this.errorLevel))
-			this.l.error(str);
-	},
-
-	warn(str) {
-		if (['warn', 'info', 'log'].includes(this.errorLevel))
-			this.l.warn(str);
-	},
-
-	info(str) {
-		if (['info', 'log'].includes(this.errorLevel))
-			this.l.info(str);
-	},
-
-	log(str) {
-		if (['log'].includes(this.errorLevel))
-			this.l.log(str);
-	}
-
-};
-
-module.exports = logger;
diff --git a/helpers/time.js b/helpers/time.js
deleted file mode 100644
index 4e46bf4..0000000
--- a/helpers/time.js
+++ /dev/null
@@ -1,18 +0,0 @@
-const constants = require('./constants.js');
-
-module.exports = {
-
-	getEpochTime: function (time) {
-		if (time === undefined) {
-			time = Date.now();
-		}
-		var d = constants.epochTime;
-		var t = d.getTime();
-		return Math.floor((time - t) / 1000);
-	},
-
-	getTime: function (time) {
-		return this.getEpochTime(time);
-	}
-
-}
diff --git a/helpers/transactionFormer.js b/helpers/transactionFormer.js
deleted file mode 100644
index 52107cd..0000000
--- a/helpers/transactionFormer.js
+++ /dev/null
@@ -1,273 +0,0 @@
-var sodium = require('sodium-browserify-tweetnacl');
-var crypto = require('crypto');
-var bignum = require('./bignumber.js');
-var keys = require('./keys.js');
-var ByteBuffer = require('bytebuffer');
-const constants = require('./constants.js');
-const time = require('./time.js');
-
-module.exports = {
-
-	createTransaction: function (type, data) {
-		switch (type) {
-			case constants.transactionTypes.SEND:
-				return this.createSendTransaction(data);
-			case constants.transactionTypes.VOTE:
-				return this.createVoteTransaction(data);
-			case constants.transactionTypes.DELEGATE:
-				return this.createDelegateTransaction(data);
-			case constants.transactionTypes.CHAT_MESSAGE:
-				return this.createChatTransaction(data);
-			case constants.transactionTypes.STATE:
-				return this.createStateTransaction(data);
-		}
-		return {};
-	},
-
-	createBasicTransaction: function (data) {
-		var transaction = { type: data.transactionType, amount: 0, timestamp: time.getTime(), asset: {}, senderPublicKey: data.keyPair.publicKey.toString('hex'), senderId: keys.createAddressFromPublicKey(data.keyPair.publicKey) };
-		return transaction;
-	},
-
-	createSendTransaction: function (data) {
-		data.transactionType = constants.transactionTypes.SEND;
-		var transaction = this.createBasicTransaction(data);
-		transaction.asset = {};
-		transaction.recipientId = data.recipientId;
-		transaction.amount = data.amount;
-		transaction.signature = this.transactionSign(transaction, data.keyPair);
-		return transaction;
-	},
-
-	createStateTransaction: function (data) {
-		data.transactionType = constants.transactionTypes.STATE;
-		var transaction = this.createBasicTransaction(data);
-		transaction.asset = {
-			"state": {
-				key: data.key,
-				value: data.value,
-				type: 0
-			}
-		};
-		transaction.recipientId = null;
-		transaction.amount = 0;
-		transaction.signature = this.transactionSign(transaction, data.keyPair);
-		return transaction;
-	},
-
-	createChatTransaction: function (data) {
-		data.transactionType = constants.transactionTypes.CHAT_MESSAGE;
-		var transaction = this.createBasicTransaction(data);
-		transaction.asset = {
-			"chat": {
-				message: data.message,
-				own_message: data.own_message,
-				type: data.message_type
-			}
-		};
-		transaction.recipientId = data.recipientId;
-		transaction.amount = data.amount || 0;
-		transaction.signature = this.transactionSign(transaction, data.keyPair);
-		return transaction;
-	},
-
-	createDelegateTransaction: function (data) {
-		data.transactionType = constants.transactionTypes.DELEGATE;
-		var transaction = this.createBasicTransaction(data);
-		transaction.asset = { "delegate": { "username": data.username, publicKey: data.keyPair.publicKey.toString('hex') } };
-		transaction.recipientId = null;
-		transaction.signature = this.transactionSign(transaction, data.keyPair);
-		return transaction;
-	},
-
-	createVoteTransaction: function (data) {
-		data.transactionType = constants.transactionTypes.VOTE;
-		var transaction = this.createBasicTransaction(data);
-		transaction.asset = { "votes": data.votes };
-		transaction.recipientId = transaction.senderId;
-		transaction.signature = this.transactionSign(transaction, data.keyPair);
-		return transaction;
-	},
-
-	getHash: function (trs) {
-		return crypto.createHash('sha256').update(this.getBytes(trs)).digest();
-	},
-
-	getBytes: function (transaction) {
-		var skipSignature = false;
-		var skipSecondSignature = true;
-		var assetSize = 0;
-		var assetBytes = null;
-
-		switch (transaction.type) {
-			case constants.transactionTypes.SEND:
-				break;
-			case constants.transactionTypes.DELEGATE:
-				assetBytes = this.delegatesGetBytes(transaction);
-				assetSize = assetBytes.length;
-				break;
-			case constants.transactionTypes.STATE:
-				assetBytes = this.statesGetBytes(transaction);
-				assetSize = assetBytes.length;
-				break;
-			case constants.transactionTypes.VOTE:
-				assetBytes = this.voteGetBytes(transaction);
-				assetSize = assetBytes.length;
-				break;
-			case constants.transactionTypes.CHAT_MESSAGE:
-				assetBytes = this.chatGetBytes(transaction);
-				assetSize = assetBytes.length;
-				break;
-			default:
-				// 'Not supported yet'
-				return 0;
-		}
-
-		var bb = new ByteBuffer(1 + 4 + 32 + 8 + 8 + 64 + 64 + assetSize, true);
-
-		bb.writeByte(transaction.type);
-		bb.writeInt(transaction.timestamp);
-
-		var senderPublicKeyBuffer = Buffer.from(transaction.senderPublicKey, 'hex');
-		for (var i = 0; i < senderPublicKeyBuffer.length; i++) {
-			bb.writeByte(senderPublicKeyBuffer[i]);
-		}
-
-		if (transaction.requesterPublicKey) {
-			var requesterPublicKey = Buffer.from(transaction.requesterPublicKey, 'hex');
-
-			for (var i = 0; i < requesterPublicKey.length; i++) {
-				bb.writeByte(requesterPublicKey[i]);
-			}
-		}
-
-		if (transaction.recipientId) {
-			var recipient = transaction.recipientId.slice(1);
-			recipient = new bignum(recipient).toBuffer({ size: 8 });
-
-			for (i = 0; i < 8; i++) {
-				bb.writeByte(recipient[i] || 0);
-			}
-		} else {
-			for (i = 0; i < 8; i++) {
-				bb.writeByte(0);
-			}
-		}
-
-		bb.writeLong(transaction.amount);
-
-		if (assetSize > 0) {
-			for (var i = 0; i < assetSize; i++) {
-				bb.writeByte(assetBytes[i]);
-			}
-		}
-
-		if (!skipSignature && transaction.signature) {
-			var signatureBuffer = Buffer.from(transaction.signature, 'hex');
-			for (var i = 0; i < signatureBuffer.length; i++) {
-				bb.writeByte(signatureBuffer[i]);
-			}
-		}
-
-		if (!skipSecondSignature && transaction.signSignature) {
-			var signSignatureBuffer = Buffer.from(transaction.signSignature, 'hex');
-			for (var i = 0; i < signSignatureBuffer.length; i++) {
-				bb.writeByte(signSignatureBuffer[i]);
-			}
-		}
-
-		bb.flip();
-		var arrayBuffer = new Uint8Array(bb.toArrayBuffer());
-		var buffer = [];
-
-		for (var i = 0; i < arrayBuffer.length; i++) {
-			buffer[i] = arrayBuffer[i];
-		}
-
-		return Buffer.from(buffer);
-	},
-
-	transactionSign: function (trs, keypair) {
-		var hash = this.getHash(trs);
-		return this.sign(hash, keypair).toString('hex');
-	},
-
-	voteGetBytes: function (trs) {
-		var buf;
-		try {
-			buf = trs.asset.votes ? Buffer.from(trs.asset.votes.join(''), 'utf8') : null;
-		} catch (e) {
-			throw e;
-		}
-		return buf;
-	},
-
-	delegatesGetBytes: function (trs) {
-		if (!trs.asset.delegate.username) {
-			return null;
-		}
-		var buf;
-
-		try {
-			buf = Buffer.from(trs.asset.delegate.username, 'utf8');
-		} catch (e) {
-			throw e;
-		}
-		return buf;
-	},
-
-	statesGetBytes: function (trs) {
-		if (!trs.asset.state.value) {
-			return null;
-		}
-		var buf;
-
-		try {
-			buf = Buffer.from([]);
-			var stateBuf = Buffer.from(trs.asset.state.value);
-			buf = Buffer.concat([buf, stateBuf]);
-			if (trs.asset.state.key) {
-				var keyBuf = Buffer.from(trs.asset.state.key);
-				buf = Buffer.concat([buf, keyBuf]);
-			}
-
-			var bb = new ByteBuffer(4 + 4, true);
-			bb.writeInt(trs.asset.state.type);
-			bb.flip();
-
-			buf = Buffer.concat([buf, bb.toBuffer()]);
-		} catch (e) {
-			throw e;
-		}
-
-		return buf;
-	},
-
-	chatGetBytes: function (trs) {
-		var buf;
-
-		try {
-			buf = Buffer.from([]);
-			var messageBuf = Buffer.from(trs.asset.chat.message, 'hex');
-			buf = Buffer.concat([buf, messageBuf]);
-
-			if (trs.asset.chat.own_message) {
-				var ownMessageBuf = Buffer.from(trs.asset.chat.own_message, 'hex');
-				buf = Buffer.concat([buf, ownMessageBuf]);
-			}
-			var bb = new ByteBuffer(4 + 4, true);
-			bb.writeInt(trs.asset.chat.type);
-			bb.flip();
-			buf = Buffer.concat([buf, Buffer.from(bb.toBuffer())]);
-		} catch (e) {
-			throw e;
-		}
-
-		return buf;
-	},
-
-	sign: function (hash, keypair) {
-		return sodium.crypto_sign_detached(hash, Buffer.from(keypair.privateKey, 'hex'));
-	}
-
-};
diff --git a/helpers/validator.js b/helpers/validator.js
deleted file mode 100644
index d1df0a8..0000000
--- a/helpers/validator.js
+++ /dev/null
@@ -1,173 +0,0 @@
-const constants = require('./constants');
-const BigNumber = require('bignumber.js')
-
-module.exports = {
-
-  getRandomIntInclusive(min, max) {
-    min = Math.ceil(min);
-    max = Math.floor(max);
-    return Math.floor(Math.random() * (max - min + 1) + min); //The maximum is inclusive and the minimum is inclusive
-  },
-
-  isNumeric(str) {
-    if (typeof str !== "string") return false
-    return !isNaN(str) && !isNaN(parseFloat(str))
-  },
-
-  tryParseJSON(jsonString) {
-    try {
-      let o = JSON.parse(jsonString);
-      if (o && typeof o === "object") {
-        return o;
-      }
-    } catch (e) { }
-    return false
-  },
-
-  validatePassPhrase(passPhrase) {
-    if (!passPhrase || typeof(passPhrase) !== 'string' || passPhrase.length < 30)
-		  return false
-    else
-      return true
-  },
-
-  validateEndpoint(endpoint) {
-    if (!endpoint || typeof(endpoint) !== 'string')
-		  return false
-    else
-      return true
-  },
-
-  validateAdmAddress(address) {
-    if (!address || typeof(address) !== 'string' || !constants.RE_ADM_ADDRESS.test(address))
-		  return false
-    else
-      return true
-  },
-
-  validateAdmPublicKey(publicKey) {
-    if (!publicKey || typeof(publicKey) !== 'string' || publicKey.length !== 64 || !constants.RE_HEX.test(publicKey))
-		  return false
-    else
-      return true
-  },
-
-  validateAdmVoteForPublicKey(publicKey) {
-    return (publicKey && typeof(publicKey) === 'string' && constants.RE_ADM_VOTE_FOR_PUBLIC_KEY.test(publicKey));
-  },
-
-  validateAdmVoteForAddress(address) {
-    return (address && typeof(address) === 'string' && constants.RE_ADM_VOTE_FOR_ADDRESS.test(address));
-  },
-
-  validateAdmVoteForDelegateName(delegateName) {
-    return (delegateName && typeof(delegateName) === 'string' && constants.RE_ADM_VOTE_FOR_DELEGATE_NAME.test(delegateName));
-  },
-
-  validateIntegerAmount(amount) {
-    if (!amount || typeof(amount) !== 'number' || isNaN(amount) || !Number.isSafeInteger(amount))
-		  return false
-    else
-      return true
-  },
-
-  validateStringAmount(amount) {
-    if (!amount || !this.isNumeric(amount))
-		  return false
-    else
-      return true
-  },
-
-  validateMessageType(message_type) {
-    if (!message_type || typeof(message_type) !== 'number' || ![1,2,3].includes(message_type))
-		  return false
-    else
-      return true
-  },
-
-  validateMessage(message, message_type) {
-    if (typeof(message) !== 'string')
-		  return {
-        result: false,
-        error: `Message must be a string`
-      }
-    else {
-      if (message_type === 2 || message_type === 3) {
-
-        let json = this.tryParseJSON(message)
-
-        if (!json)
-          return {
-            result: false,
-            error: `For rich and signal messages, 'message' must be a JSON string`
-          }
-
-        if (json.type && json.type.toLowerCase().includes('_transaction'))
-          if (json.type.toLowerCase() !== json.type)
-            return {
-              result: false,
-              error: `Value '<coin>_transaction' must be in lower case`
-            }
-
-        if (typeof json.amount !== 'string' || !this.validateStringAmount(json.amount))
-          return {
-            result: false,
-            error: `Field 'amount' must be a string, representing a number`
-          }
-
-      }
-    }
-    return {
-      result: true
-    }
-  },
-
-  validateDelegateName(name) {
-    if (typeof name !== 'string') {
-      return false;
-    }
-
-    return constants.RE_ADM_DELEGATE_NAME.test(name);
-  },
-
-  AdmToSats(amount) {
-    return BigNumber(String(amount)).multipliedBy(constants.SAT).integerValue().toNumber()
-  },
-
-  badParameter(name, value, customMessage) {
-    return new Promise((resolve, reject) => {
-      resolve({
-        success: false,
-        errorMessage: `Wrong '${name}' parameter${value ? ': ' + value : ''}${customMessage ? '. Error: ' + customMessage : ''}`
-      })
-    })
-  },
-
-  formatRequestResults(response, isRequestSuccess) {
-    let results = {};
-    results.details = {};
-
-    if (isRequestSuccess) {
-      results.success = response.data && response.data.success;
-      results.data = response.data;
-      results.details.status = response.status;
-      results.details.statusText = response.statusText;
-      results.details.response = response;
-      if (!results.success && results.data)
-        results.errorMessage = `Node's reply: ${results.data.error}`
-    } else {
-      results.success = false;
-      results.data = undefined;
-      results.details.status = response.response ? response.response.status : undefined;
-      results.details.statusText = response.response ? response.response.statusText : undefined;
-      results.details.error = response.toString();
-      results.details.message = response.response && response.response.data ? response.response.data.toString().trim() : undefined;
-      results.details.response = response.response;
-      results.errorMessage = `${results.details.error}${results.details.message ? '. Message: ' + results.details.message : ''}`;
-    }
-
-    return results;
-
-  }
-
-};
diff --git a/helpers/wsClient.js b/helpers/wsClient.js
deleted file mode 100644
index 05853b7..0000000
--- a/helpers/wsClient.js
+++ /dev/null
@@ -1,100 +0,0 @@
-const ioClient = require("socket.io-client");
-const logger = require('./logger');
-const validator = require('./validator');
-
-module.exports = {
-	
-	isSocketEnabled: false, // If we need socket connection
-	wsType: "ws", // Socket connection type, "ws" (default) or "wss"
-	admAddress: '', // ADM address to subscribe to notifications
-	connection: null, // Socket connection
-	onNewMessage: null, // Method to process new messages or transactions
-	activeNodes: [], // List of nodes that are active. Not all of them synced and support socket.
-	activeSocketNodes: [], // List of nodes that are active, synced and support socket
-	useFastest: false, // If to connect to node with minimum ping. Not recommended.
-
-	// Constructor
-	initSocket(params) {
-		this.onNewMessage = params.onNewMessage;
-		this.isSocketEnabled = params.socket;
-		this.wsType = params.wsType;
-		this.admAddress = params.admAddress;
-	},
-
-	// Runs after every healthCheck() to re-connect socket if needed
-	reviseConnection(nodes) {
-		if (!this.isSocketEnabled) {
-			return;
-		}
-		if (!this.connection || !this.connection.connected) {
-			this.activeNodes = nodes.slice();
-			this.setNodes();
-			this.setConnection();
-		}
-	},
-
-	// Make socket connection and subscribe to new transactions
-	setConnection() {
-		if (this.activeSocketNodes.length === 0) {
-			logger.warn(`[Socket] No supported socket nodes at the moment.`);
-			return;
-		}
-
-		const node = this.socketAddress();
-		logger.log(`[Socket] Supported nodes: ${this.activeSocketNodes.length}. Connecting to ${node}...`);
-		this.connection = ioClient.connect(node, { reconnection: false, timeout: 5000 });
-
-		this.connection.on('connect', () => {
-			this.connection.emit('address', this.admAddress);
-			logger.info('[Socket] Connected to ' + node + ' and subscribed to incoming transactions for ' + this.admAddress + '.');
-		});
-
-		this.connection.on('disconnect', reason => {
-			logger.warn('[Socket] Disconnected. Reason: ' + reason)
-		});
-
-		this.connection.on('connect_error', (err) => {
-			logger.warn('[Socket] Connection error: ' + err)
-		});
-
-		this.connection.on('newTrans', transaction => {
-			if ((transaction.recipientId === this.admAddress) && (transaction.type === 0 || transaction.type === 8)) {
-				// console.info(`[Socket] New incoming socket transaction received: ${transaction.id}`);
-				this.onNewMessage(transaction);
-			}
-		});
-	},
-
-	// Save the list of nodes activeSocketNodes that are active, synced and support socket
-	setNodes() {
-		this.activeSocketNodes = this.activeNodes.filter(n => n.socketSupport & !n.outOfSync);
-		// Remove nodes without IP if "ws" connection type
-		if (this.wsType === "ws") {
-			this.activeSocketNodes = this.activeSocketNodes.filter(n => !n.ifHttps || n.ip);
-		}
-	},
-
-	// Returns socket url for connection
-	socketAddress() {
-		const node = this.useFastest ? this.fastestNode() : this.randomNode();
-		let socketUrl = this.wsType + "://";
-		if (this.wsType === "ws") {
-			let host = node.ip;
-			if (!host || host === undefined)
-				host = node.url;
-			socketUrl = socketUrl + host + ":" + node.wsPort
-		} else {
-			socketUrl = socketUrl + node.url; // no port if wss
-		}
-		return socketUrl;
-	},
-
-	fastestNode() {
-		return this.activeSocketNodes[0]; // They are sorted by ping
-	},
-
-	randomNode() {
-		return this.activeSocketNodes[validator.getRandomIntInclusive(0, this.activeSocketNodes.length - 1)]
-	}
-
-}
diff --git a/package.json b/package.json
index 7a7c87e..9ce49f2 100644
--- a/package.json
+++ b/package.json
@@ -2,16 +2,20 @@
 	"name": "adamant-api",
 	"version": "1.5.0",
 	"description": "REST API for ADAMANT Blockchain",
-	"main": "index.js",
+	"main": "src/index.js",
 	"scripts": {
-		"test": "echo \"Error: no test specified\" && exit 1"
+		"test": "jest",
+		"lint": "eslint src",
+		"lint:fix": "eslint --fix src",
+		"prepare": "husky install"
 	},
-	"author": "RomanS, Aleksei Lebedev <devs@adamant.im> (https://adamant.im)",
+	"author": "ADAMANT Foundation <devs@adamant.im> (https://adamant.im)",
 	"license": "GPL-3.0",
 	"dependencies": {
+		"@liskhq/lisk-cryptography": "3.2.0",
 		"axios": "^0.25.0",
 		"bignumber.js": "^9.0.2",
-    "bitcoinjs-lib": "^5.2.0",
+		"bitcoinjs-lib": "^5.2.0",
 		"bitcore-mnemonic": "^8.25.25",
 		"bytebuffer": "^5.0.1",
 		"coininfo": "^5.1.0",
@@ -19,7 +23,6 @@
 		"ethereumjs-util": "^7.1.4",
 		"hdkey": "^2.0.1",
 		"pbkdf2": "^3.1.2",
-    "@liskhq/lisk-cryptography": "3.2.0",
 		"socket.io-client": "^2.4.0",
 		"sodium-browserify-tweetnacl": "^0.2.6"
 	},
@@ -58,5 +61,14 @@
 	"bugs": {
 		"url": "https://github.com/Adamant-im/adamant-api-jsclient/issues"
 	},
-	"homepage": "https://github.com/Adamant-im/adamant-api-jsclient#readme"
+	"homepage": "https://github.com/Adamant-im/adamant-api-jsclient#readme",
+	"devDependencies": {
+		"@commitlint/cli": "^16.2.1",
+		"@commitlint/config-conventional": "^16.2.1",
+		"eslint": "^8.9.0",
+		"eslint-config-google": "^0.14.0",
+		"eslint-plugin-jest": "^26.1.0",
+		"husky": "^7.0.4",
+		"jest": "^27.5.1"
+	}
 }
diff --git a/groups/btc.js b/src/groups/btc.js
similarity index 57%
rename from groups/btc.js
rename to src/groups/btc.js
index 601023f..40c4771 100644
--- a/groups/btc.js
+++ b/src/groups/btc.js
@@ -1,6 +1,6 @@
-var bitcoin = require('bitcoinjs-lib');
-var coinNetworks = require('./coinNetworks');
-const btc = { }
+const bitcoin = require('bitcoinjs-lib');
+const coinNetworks = require('./coinNetworks');
+const btc = { };
 
 /**
  * Generates a BTC account from the passphrase specified.
@@ -8,20 +8,19 @@ const btc = { }
  * @returns {object} network info, keyPair, privateKey, privateKeyWIF
  */
 
-btc.keys = passphrase => {
+btc.keys = (passphrase) => {
   const network = coinNetworks.BTC;
   const pwHash = bitcoin.crypto.sha256(Buffer.from(passphrase));
-  const keyPair = bitcoin.ECPair.fromPrivateKey(pwHash, { network });
+  const keyPair = bitcoin.ECPair.fromPrivateKey(pwHash, {network});
 
   return {
     network,
     keyPair,
-    address: bitcoin.payments.p2pkh({ pubkey: keyPair.publicKey, network }).address,
+    address: bitcoin.payments.p2pkh({pubkey: keyPair.publicKey, network}).address,
     // BTC private key is a regular 256-bit key
     privateKey: keyPair.privateKey.toString('hex'), // regular 256-bit (32 bytes, 64 characters) private key
-    privateKeyWIF: keyPair.toWIF() // Wallet Import Format (52 base58 characters)
-  }
-
+    privateKeyWIF: keyPair.toWIF(), // Wallet Import Format (52 base58 characters)
+  };
 };
 
 module.exports = btc;
diff --git a/groups/coinNetworks.js b/src/groups/coinNetworks.js
similarity index 78%
rename from groups/coinNetworks.js
rename to src/groups/coinNetworks.js
index 3a42b31..d3bc749 100644
--- a/groups/coinNetworks.js
+++ b/src/groups/coinNetworks.js
@@ -1,4 +1,4 @@
-coininfo = require('coininfo');
+const coininfo = require('coininfo');
 
 module.exports = {
   DOGE: coininfo.dogecoin.main.toBitcoinJS(),
@@ -8,6 +8,6 @@ module.exports = {
     name: 'Lisk',
     port: 8000,
     wsPort: 8001,
-    unit: 'LSK'
+    unit: 'LSK',
   },
-}
+};
diff --git a/groups/dash.js b/src/groups/dash.js
similarity index 58%
rename from groups/dash.js
rename to src/groups/dash.js
index fc95ee8..80daec5 100644
--- a/groups/dash.js
+++ b/src/groups/dash.js
@@ -1,6 +1,6 @@
-var bitcoin = require('bitcoinjs-lib');
-var coinNetworks = require('./coinNetworks');
-const dash = { }
+const bitcoin = require('bitcoinjs-lib');
+const coinNetworks = require('./coinNetworks');
+const dash = { };
 
 /**
  * Generates a DASH account from the passphrase specified.
@@ -8,20 +8,19 @@ const dash = { }
  * @returns {object} network info, keyPair, privateKey, privateKeyWIF
  */
 
-dash.keys = passphrase => {
+dash.keys = (passphrase) => {
   const network = coinNetworks.DASH;
   const pwHash = bitcoin.crypto.sha256(Buffer.from(passphrase));
-  const keyPair = bitcoin.ECPair.fromPrivateKey(pwHash, { network });
+  const keyPair = bitcoin.ECPair.fromPrivateKey(pwHash, {network});
 
   return {
     network,
     keyPair,
-    address: bitcoin.payments.p2pkh({ pubkey: keyPair.publicKey, network }).address,
+    address: bitcoin.payments.p2pkh({pubkey: keyPair.publicKey, network}).address,
     // DASH private key is a regular 256-bit key
     privateKey: keyPair.privateKey.toString('hex'), // regular 256-bit (32 bytes, 64 characters) private key
-    privateKeyWIF: keyPair.toWIF() // Wallet Import Format (52 base58 characters)
-  }
-
+    privateKeyWIF: keyPair.toWIF(), // Wallet Import Format (52 base58 characters)
+  };
 };
 
 module.exports = dash;
diff --git a/src/groups/decodeMsg.js b/src/groups/decodeMsg.js
new file mode 100644
index 0000000..3b700c1
--- /dev/null
+++ b/src/groups/decodeMsg.js
@@ -0,0 +1,83 @@
+const ed2curve = require('ed2curve');
+const nacl = require('tweetnacl/nacl-fast');
+const keys = require('../helpers/keys');
+
+module.exports = (msg, senderPublicKey, passPhrase, nonce) => {
+  const keypair = keys.createKeypairFromPassPhrase(passPhrase);
+
+  let {privateKey} = keypair;
+
+  if (typeof msg === 'string') {
+    msg = hexToBytes(msg);
+  }
+
+  if (typeof nonce === 'string') {
+    nonce = hexToBytes(nonce);
+  }
+
+  if (typeof senderPublicKey === 'string') {
+    senderPublicKey = hexToBytes(senderPublicKey);
+  }
+
+  if (typeof privateKey === 'string') {
+    privateKey = hexToBytes(privateKey);
+  }
+
+  const DHPublicKey = ed2curve.convertPublicKey(senderPublicKey);
+  const DHSecretKey = ed2curve.convertSecretKey(privateKey);
+  const decrypted = nacl.box.open(msg, nonce, DHPublicKey, DHSecretKey);
+
+  return decrypted ? utf8ArrayToStr(decrypted) : '';
+};
+
+function hexToBytes(hexString = '') {
+  const bytes = [];
+
+  for (let c = 0; c < hexString.length; c += 2) {
+    bytes.push(parseInt(hexString.substring(c, c + 2), 16));
+  }
+
+  return Uint8Array.from(bytes);
+}
+
+function utf8ArrayToStr(array) {
+  const len = array.length;
+  let out = '';
+  let i = 0;
+  let c;
+  let char2;
+  let char3;
+
+  while (i < len) {
+    c = array[i++];
+    switch (c >> 4) {
+      case 0:
+      case 1:
+      case 2:
+      case 3:
+      case 4:
+      case 5:
+      case 6:
+      case 7:
+        // 0xxxxxxx
+        out += String.fromCharCode(c);
+        break;
+      case 12:
+      case 13:
+        // 110x xxxx   10xx xxxx
+        char2 = array[i++];
+        out += String.fromCharCode(((c & 0x1F) << 6) | (char2 & 0x3F));
+        break;
+      case 14:
+        // 1110 xxxx  10xx xxxx  10xx xxxx
+        char2 = array[i++];
+        char3 = array[i++];
+        out += String.fromCharCode(((c & 0x0F) << 12) |
+          ((char2 & 0x3F) << 6) |
+          ((char3 & 0x3F) << 0));
+        break;
+    }
+  }
+
+  return out;
+}
diff --git a/groups/doge.js b/src/groups/doge.js
similarity index 58%
rename from groups/doge.js
rename to src/groups/doge.js
index 08eca09..ceb0ad5 100644
--- a/groups/doge.js
+++ b/src/groups/doge.js
@@ -1,6 +1,6 @@
-var bitcoin = require('bitcoinjs-lib');
-var coinNetworks = require('./coinNetworks');
-const doge = { }
+const bitcoin = require('bitcoinjs-lib');
+const coinNetworks = require('./coinNetworks');
+const doge = { };
 
 /**
  * Generates a DOGE account from the passphrase specified.
@@ -8,20 +8,19 @@ const doge = { }
  * @returns {object} network info, keyPair, privateKey, privateKeyWIF
  */
 
-doge.keys = passphrase => {
+doge.keys = (passphrase) => {
   const network = coinNetworks.DOGE;
   const pwHash = bitcoin.crypto.sha256(Buffer.from(passphrase));
-  const keyPair = bitcoin.ECPair.fromPrivateKey(pwHash, { network });
+  const keyPair = bitcoin.ECPair.fromPrivateKey(pwHash, {network});
 
   return {
     network,
     keyPair,
-    address: bitcoin.payments.p2pkh({ pubkey: keyPair.publicKey, network }).address,
+    address: bitcoin.payments.p2pkh({pubkey: keyPair.publicKey, network}).address,
     // DOGE private key is a regular 256-bit key
     privateKey: keyPair.privateKey.toString('hex'), // regular 256-bit (32 bytes, 64 characters) private key
-    privateKeyWIF: keyPair.toWIF() // Wallet Import Format (52 base58 characters)
-  }
-
+    privateKeyWIF: keyPair.toWIF(), // Wallet Import Format (52 base58 characters)
+  };
 };
 
 module.exports = doge;
diff --git a/src/groups/eth.js b/src/groups/eth.js
new file mode 100644
index 0000000..524f43e
--- /dev/null
+++ b/src/groups/eth.js
@@ -0,0 +1,24 @@
+const Mnemonic = require('bitcore-mnemonic');
+const hdkey = require('hdkey');
+const HD_KEY_PATH = 'm/44\'/60\'/3\'/1/0';
+const {bufferToHex, privateToAddress} = require('ethereumjs-util');
+const eth = { };
+
+/**
+ * Generates a ETH account from the passphrase specified.
+ * @param {string} passphrase ADAMANT account passphrase
+ * @returns {{address: String, privateKey: Buffer}}
+ */
+
+eth.keys = (passphrase) => {
+  const mnemonic = new Mnemonic(passphrase, Mnemonic.Words.ENGLISH);
+  const seed = mnemonic.toSeed();
+  const privateKey = hdkey.fromMasterSeed(seed).derive(HD_KEY_PATH)._privateKey;
+
+  return {
+    address: bufferToHex(privateToAddress(privateKey)),
+    privateKey: bufferToHex(privateKey),
+  };
+};
+
+module.exports = eth;
diff --git a/src/groups/get.js b/src/groups/get.js
new file mode 100644
index 0000000..8090efa
--- /dev/null
+++ b/src/groups/get.js
@@ -0,0 +1,48 @@
+const axios = require('../helpers/axiosClient');
+const logger = require('../helpers/logger');
+const validator = require('../helpers/validator');
+
+const DEFAULT_GET_REQUEST_RETRIES = 3; // How much re-tries for get-requests by default. Total 3+1 tries
+
+module.exports = (nodeManager) => {
+  return (endpoint, params, maxRetries = DEFAULT_GET_REQUEST_RETRIES, retryNo = 0) => {
+    let url = trimAny(endpoint, '/ ').replace(/^api\//, '');
+    if (!url || !validator.validateEndpoint(endpoint)) {
+      return validator.badParameter('endpoint');
+    }
+
+    url = nodeManager.node() + '/api/' + url;
+    return axios.get(url, {params})
+        .then(function(response) {
+          return validator.formatRequestResults(response, true);
+        })
+        .catch(function(error) {
+          const logMessage = `[ADAMANT js-api] Get-request: Request to ${url} failed with ${error.response ? error.response.status : undefined} status code, ${error.toString()}${error.response && error.response.data ? '. Message: ' + error.response.data.toString().trim() : ''}. Try ${retryNo + 1} of ${maxRetries + 1}.`;
+          if (retryNo < maxRetries) {
+            logger.log(`${logMessage} Retrying…`);
+            return nodeManager.changeNodes()
+                .then(function() {
+                  return module.exports(nodeManager)(endpoint, params, maxRetries, ++retryNo);
+                });
+          }
+          logger.warn(`${logMessage} No more attempts, returning error.`);
+          return validator.formatRequestResults(error, false);
+        });
+  };
+};
+
+function trimAny(str, chars) {
+  if (!str || typeof str !== 'string') {
+    return '';
+  }
+  let start = 0;
+  let end = str.length;
+  while (start < end && chars.indexOf(str[start]) >= 0) {
+    ++start;
+  }
+  while (end > start && chars.indexOf(str[end - 1]) >= 0) {
+    --end;
+  }
+  return (start > 0 || end < str.length) ? str.substring(start, end) : str;
+}
+
diff --git a/groups/getPublicKey.js b/src/groups/getPublicKey.js
similarity index 73%
rename from groups/getPublicKey.js
rename to src/groups/getPublicKey.js
index dc40b21..1ce213f 100644
--- a/groups/getPublicKey.js
+++ b/src/groups/getPublicKey.js
@@ -3,19 +3,18 @@ const logger = require('../helpers/logger');
 const publicKeysCache = { };
 
 module.exports = (nodeManager) => {
-
   return async (address) => {
-    if (publicKeysCache[address])
-      return publicKeysCache[address]
-  
-    const publicKey = await get(nodeManager)('/accounts/getPublicKey', { address });  
+    if (publicKeysCache[address]) {
+      return publicKeysCache[address];
+    }
+
+    const publicKey = await get(nodeManager)('/accounts/getPublicKey', {address});
     if (publicKey.success) {
       publicKeysCache[address] = publicKey.data.publicKey;
-      return publicKey.data.publicKey
+      return publicKey.data.publicKey;
     } else {
       logger.warn(`[ADAMANT js-api] Failed to get public key for ${address}. ${publicKey.errorMessage}.`);
-      return false
+      return false;
     }
-  }
-
+  };
 };
diff --git a/groups/lsk.js b/src/groups/lsk.js
similarity index 85%
rename from groups/lsk.js
rename to src/groups/lsk.js
index 51f467b..9d2ea53 100644
--- a/groups/lsk.js
+++ b/src/groups/lsk.js
@@ -1,5 +1,5 @@
-const cryptography = require('@liskhq/lisk-cryptography')
-const sodium = require('sodium-browserify-tweetnacl')
+const cryptography = require('@liskhq/lisk-cryptography');
+const sodium = require('sodium-browserify-tweetnacl');
 const pbkdf2 = require('pbkdf2');
 
 const coinNetworks = require('./coinNetworks');
@@ -11,8 +11,8 @@ const LiskHashSettings = {
   SALT: 'adm',
   ITERATIONS: 2048,
   KEYLEN: 32,
-  DIGEST: 'sha256'
-}
+  DIGEST: 'sha256',
+};
 
 /**
  * Generates a LSK account from the passphrase specified.
@@ -20,7 +20,7 @@ const LiskHashSettings = {
  * @returns {object} network info, keyPair, address, addressHexBinary, addressHex, privateKey
  */
 
-lsk.keys = passphrase => {
+lsk.keys = (passphrase) => {
   const network = coinNetworks.LSK;
   const liskSeed = pbkdf2.pbkdf2Sync(passphrase, LiskHashSettings.SALT, LiskHashSettings.ITERATIONS, LiskHashSettings.KEYLEN, LiskHashSettings.DIGEST);
   const keyPair = sodium.crypto_sign_seed_keypair(liskSeed);
@@ -35,8 +35,8 @@ lsk.keys = passphrase => {
     address,
     addressHexBinary,
     addressHex,
-    privateKey
-  }
+    privateKey,
+  };
 };
 
 module.exports = lsk;
diff --git a/groups/newDelegate.js b/src/groups/newDelegate.js
similarity index 80%
rename from groups/newDelegate.js
rename to src/groups/newDelegate.js
index 1906f9a..48088b2 100644
--- a/groups/newDelegate.js
+++ b/src/groups/newDelegate.js
@@ -1,4 +1,4 @@
-const axios = require('axios');
+const axios = require('../helpers/axiosClient');
 const logger = require('../helpers/logger');
 const keys = require('../helpers/keys');
 const constants = require('../helpers/constants');
@@ -9,27 +9,27 @@ const DEFAULT_NEW_DELEGATE_RETRIES = 4; // How much re-tries for send tokens req
 
 module.exports = (nodeManager) => {
   /**
-		* Registers user account as delegate
+    * Registers user account as delegate
     * @param {string} passPhrase Senders's passPhrase. Sender's address will be derived from it.
     * @param {string} username Delegate name you want to register with.
     * It must be unique in ADAMANT blockchain. It should not be similar to ADAMANT address.
     * Delegate name can only contain alphanumeric characters and symbols !@$&_.
     * @param {number} maxRetries How much times to retry request
-    * @returns {Promise} Request results
-  	*/
-	return async (passPhrase, username, maxRetries = DEFAULT_NEW_DELEGATE_RETRIES, retryNo = 0) => {
-
+    * @param {number} retryNo Number of request already made
+    * @return {Promise} Request results
+  */
+  return async (passPhrase, username, maxRetries = DEFAULT_NEW_DELEGATE_RETRIES, retryNo = 0) => {
     let transaction;
 
     try {
       if (!validator.validatePassPhrase(passPhrase)) {
-			  return validator.badParameter('passPhrase');
+        return validator.badParameter('passPhrase');
       }
 
       const keyPair = keys.createKeypairFromPassPhrase(passPhrase);
 
       if (!validator.validateDelegateName(username)) {
-			  return validator.badParameter('username');
+        return validator.badParameter('username');
       }
 
       const type = constants.transactionTypes.DELEGATE;
@@ -41,7 +41,6 @@ module.exports = (nodeManager) => {
       };
 
       transaction = transactionFormer.createTransaction(type, data);
-
     } catch (e) {
       return validator.badParameter('#exception_catched#', e);
     }
@@ -59,14 +58,14 @@ module.exports = (nodeManager) => {
         logger.log(`${logMessage} Retrying…`);
 
         return nodeManager.changeNodes()
-          .then(() => (
-            module.exports(nodeManager)(passPhrase, addressOrPublicKey, amount, isAmountInADM, maxRetries, ++retryNo)
-          ));
+            .then(() => (
+              module.exports(nodeManager)(passPhrase, username, maxRetries, ++retryNo)
+            ));
       }
 
       logger.warn(`${logMessage} No more attempts, returning error.`);
 
       return validator.formatRequestResults(error, false);
     }
-  }
+  };
 };
diff --git a/src/groups/sendMessage.js b/src/groups/sendMessage.js
new file mode 100644
index 0000000..e402f34
--- /dev/null
+++ b/src/groups/sendMessage.js
@@ -0,0 +1,142 @@
+const axios = require('../helpers/axiosClient');
+const logger = require('../helpers/logger');
+const keys = require('../helpers/keys');
+const constants = require('../helpers/constants');
+const encryptor = require('../helpers/encryptor');
+const transactionFormer = require('../helpers/transactionFormer');
+const validator = require('../helpers/validator');
+const getPublicKey = require('./getPublicKey');
+
+const DEFAULT_SEND_MESSAGE_RETRIES = 4; // How much re-tries for send message requests by default. Total 4+1 tries
+
+module.exports = (nodeManager) => {
+  /**
+    * Encrypts a message, creates Message transaction, signs it, and broadcasts to ADAMANT network. Supports Basic, Rich and Signal Message Types.
+    * See https://github.com/Adamant-im/adamant/wiki/Message-Types
+    * @param {string} passPhrase Senders's passPhrase. Sender's address will be derived from it.
+    * @param {string} addressOrPublicKey Recipient's ADAMANT address or public key.
+    * Using public key is faster, as the library wouldn't request it from the network.
+    * Though we cache public keys, and next request with address will be processed as fast as with public key.
+    * @param {string} message Message plain text in case of basic message. Stringified JSON in case of rich or signal messages. The library will encrypt a message.
+    * Example of rich message for Ether in-chat transfer:
+    * `{"type":"eth_transaction","amount":"0.002","hash":"0xfa46d2b3c99878f1f9863fcbdb0bc27d220d7065c6528543cbb83ced84487deb","comments":"I like to send it, send it"}`
+    * @param {string | number} messageType Type of message: basic, rich, or signal
+    * @param {string | number} amount Amount to send with a message
+    * @param {boolean} isAmountInADM If amount specified in ADM, or in sats (10^-8 ADM)
+    * @param {number} maxRetries How much times to retry request
+    * @param {number} retryNo Number of request already made
+    * @return {Promise} Request results
+  */
+  return async (passPhrase, addressOrPublicKey, message, messageType = 'basic', amount, isAmountInADM = true, maxRetries = DEFAULT_SEND_MESSAGE_RETRIES, retryNo = 0) => {
+    let keyPair;
+    let data;
+    let address;
+    let publicKey;
+
+    try {
+      if (!validator.validatePassPhrase(passPhrase)) {
+        return validator.badParameter('passPhrase');
+      }
+
+      keyPair = keys.createKeypairFromPassPhrase(passPhrase);
+
+      if (!validator.validateAdmAddress(addressOrPublicKey)) {
+        if (!validator.validateAdmPublicKey(addressOrPublicKey)) {
+          return validator.badParameter('addressOrPublicKey', addressOrPublicKey);
+        } else {
+          publicKey = addressOrPublicKey;
+          try {
+            address = keys.createAddressFromPublicKey(publicKey);
+          } catch (e) {
+            return validator.badParameter('addressOrPublicKey', addressOrPublicKey);
+          }
+        }
+      } else {
+        publicKey = '';
+        address = addressOrPublicKey;
+      }
+
+      const messageTypes = {
+        basic: 1,
+        rich: 2,
+        signal: 3,
+      };
+
+      messageType = messageTypes[messageType];
+
+      if (!validator.validateMessageType(messageType)) {
+        return validator.badParameter('messageType', messageType);
+      }
+
+      const messageValidation = validator.validateMessage(message, messageType);
+
+      if (!messageValidation.result) {
+        return validator.badParameter('message', message, messageValidation.error);
+      }
+
+      data = {
+        keyPair,
+        recipientId: address,
+        message_type: messageType,
+      };
+
+      if (amount) {
+        let amountInSat = amount;
+
+        if (isAmountInADM) {
+          amountInSat = validator.admToSats(amount);
+        }
+
+        if (!validator.validateIntegerAmount(amountInSat)) {
+          return validator.badParameter('amount', amount);
+        }
+
+        data.amount = amountInSat;
+      }
+    } catch (e) {
+      return validator.badParameter('#exception_catched#', e);
+    }
+
+    if (!publicKey) {
+      publicKey = await getPublicKey(nodeManager)(address);
+    }
+
+    if (!publicKey) {
+      return {
+        success: false,
+        errorMessage: `Unable to get public key for ${addressOrPublicKey}. It is necessary for sending an encrypted message. Account may be uninitialized (https://medium.com/adamant-im/chats-and-uninitialized-accounts-in-adamant-5035438e2fcd), or network error`,
+      };
+    }
+
+    try {
+      const encryptedMessage = encryptor.encodeMessage(message, keyPair, publicKey);
+      data.message = encryptedMessage.message;
+      data.own_message = encryptedMessage.own_message;
+
+      const transaction = transactionFormer.createTransaction(constants.transactionTypes.CHAT_MESSAGE, data);
+
+      const url = nodeManager.node() + '/api/transactions/process';
+      return axios.post(url, {transaction})
+          .then(function(response) {
+            return validator.formatRequestResults(response, true);
+          })
+          .catch(function(error) {
+            const logMessage = `[ADAMANT js-api] Send message request: Request to ${url} failed with ${error.response ? error.response.status : undefined} status code, ${error.toString()}${error.response && error.response.data ? '. Message: ' + error.response.data.toString().trim() : ''}. Try ${retryNo+1} of ${maxRetries+1}.`;
+            if (retryNo < maxRetries) {
+              logger.log(`${logMessage} Retrying…`);
+              return nodeManager.changeNodes()
+                  .then(function() {
+                    return module.exports(nodeManager)(passPhrase, addressOrPublicKey, message, messageType, amount, isAmountInADM, maxRetries, ++retryNo);
+                  });
+            }
+            logger.warn(`${logMessage} No more attempts, returning error.`);
+            return validator.formatRequestResults(error, false);
+          });
+    } catch (e) {
+      return {
+        success: false,
+        errorMessage: `Unable to encode message '${message}' with public key ${publicKey}, or unable to build a transaction. Exception: ` + e,
+      };
+    }
+  }; // sendMessage()
+};
diff --git a/src/groups/sendTokens.js b/src/groups/sendTokens.js
new file mode 100644
index 0000000..11d5fce
--- /dev/null
+++ b/src/groups/sendTokens.js
@@ -0,0 +1,89 @@
+const axios = require('../helpers/axiosClient');
+const logger = require('../helpers/logger');
+const keys = require('../helpers/keys');
+const constants = require('../helpers/constants');
+const transactionFormer = require('../helpers/transactionFormer');
+const validator = require('../helpers/validator');
+
+const DEFAULT_SEND_TOKENS_RETRIES = 4; // How much re-tries for send tokens requests by default. Total 4+1 tries
+
+module.exports = (nodeManager) => {
+  /**
+    * Creates Token Transfer transaction, signs it, and broadcasts to ADAMANT network
+    * See https://github.com/Adamant-im/adamant/wiki/Transaction-Types#type-0-token-transfer-transaction
+    * @param {string} passPhrase Senders's passPhrase. Sender's address will be derived from it.
+    * @param {string} addressOrPublicKey Recipient's ADAMANT address or public key.
+    * Address is preferred, as if we get public key, we should derive address from it.
+    * @param {string | number} amount Amount to send
+    * @param {boolean} isAmountInADM If amount specified in ADM, or in sats (10^-8 ADM)
+    * @param {number} maxRetries How much times to retry request
+    * @param {number} retryNo Number of request already made
+    * @return {Promise} Request results
+  */
+  return (passPhrase, addressOrPublicKey, amount, isAmountInADM = true, maxRetries = DEFAULT_SEND_TOKENS_RETRIES, retryNo = 0) => {
+    let transaction;
+    let address; let publicKey;
+
+    try {
+      if (!validator.validatePassPhrase(passPhrase)) {
+        return validator.badParameter('passPhrase');
+      }
+
+      const keyPair = keys.createKeypairFromPassPhrase(passPhrase);
+
+      if (!validator.validateAdmAddress(addressOrPublicKey)) {
+        if (!validator.validateAdmPublicKey(addressOrPublicKey)) {
+          return validator.badParameter('addressOrPublicKey', addressOrPublicKey);
+        } else {
+          publicKey = addressOrPublicKey;
+          try {
+            address = keys.createAddressFromPublicKey(publicKey);
+          } catch (e) {
+            return validator.badParameter('addressOrPublicKey', addressOrPublicKey);
+          }
+        }
+      } else {
+        publicKey = '';
+        address = addressOrPublicKey;
+      }
+
+      let amountInSat = amount;
+
+      if (isAmountInADM) {
+        amountInSat = validator.admToSats(amount);
+      }
+
+      if (!validator.validateIntegerAmount(amountInSat)) {
+        return validator.badParameter('amount', amount);
+      }
+
+      const data = {
+        keyPair,
+        recipientId: address,
+        amount: amountInSat,
+      };
+
+      transaction = transactionFormer.createTransaction(constants.transactionTypes.SEND, data);
+    } catch (e) {
+      return validator.badParameter('#exception_catched#', e);
+    }
+
+    const url = nodeManager.node() + '/api/transactions/process';
+    return axios.post(url, {transaction})
+        .then(function(response) {
+          return validator.formatRequestResults(response, true);
+        })
+        .catch(function(error) {
+          const logMessage = `[ADAMANT js-api] Send tokens request: Request to ${url} failed with ${error.response ? error.response.status : undefined} status code, ${error.toString()}${error.response && error.response.data ? '. Message: ' + error.response.data.toString().trim() : ''}. Try ${retryNo + 1} of ${maxRetries + 1}.`;
+          if (retryNo < maxRetries) {
+            logger.log(`${logMessage} Retrying…`);
+            return nodeManager.changeNodes()
+                .then(function() {
+                  return module.exports(nodeManager)(passPhrase, addressOrPublicKey, amount, isAmountInADM, maxRetries, ++retryNo);
+                });
+          }
+          logger.warn(`${logMessage} No more attempts, returning error.`);
+          return validator.formatRequestResults(error, false);
+        });
+  };
+};
diff --git a/groups/voteForDelegate.js b/src/groups/voteForDelegate.js
similarity index 85%
rename from groups/voteForDelegate.js
rename to src/groups/voteForDelegate.js
index 1d37d67..5ef15c0 100644
--- a/groups/voteForDelegate.js
+++ b/src/groups/voteForDelegate.js
@@ -1,4 +1,4 @@
-const axios = require('axios');
+const axios = require('../helpers/axiosClient');
 const get = require('./get');
 const logger = require('../helpers/logger');
 const keys = require('../helpers/keys');
@@ -12,21 +12,21 @@ const publicKeysCache = { };
 
 module.exports = (nodeManager) => {
   /**
-		* Creates votes for delegate transaction, signs it, and broadcasts to ADAMANT network
+    * Creates votes for delegate transaction, signs it, and broadcasts to ADAMANT network
     * See https://github.com/Adamant-im/adamant/wiki/Transaction-Types#type-3-vote-for-delegate-transaction
     * @param {string} passPhrase Senders's passPhrase. Sender's address will be derived from it.
     * @param {string[]} votes PublicKeys, ADM addresses and delegate names for upvote and downvote.
     * It would be more efficient to pass publicKey, otherwise the api will make additional queries
     * @param {number} maxRetries How much times to retry request
-    * @returns {Promise} Request results
-  	*/
-	return async (passPhrase, votes, maxRetries = DEFAULT_VOTE_FOR_DELEGATE_RETRIES, retryNo = 0) => {
-
+    * @param {number} retryNo Number of request already made
+    * @return {Promise} Request results
+  */
+  return async (passPhrase, votes, maxRetries = DEFAULT_VOTE_FOR_DELEGATE_RETRIES, retryNo = 0) => {
     let transaction;
 
     try {
       if (!validator.validatePassPhrase(passPhrase)) {
-			  return validator.badParameter('passPhrase');
+        return validator.badParameter('passPhrase');
       }
 
       const keyPair = keys.createKeypairFromPassPhrase(passPhrase);
@@ -44,7 +44,7 @@ module.exports = (nodeManager) => {
           votes[i] = `${voteDirection}${cachedPublicKey}`;
         } else {
           if (validator.validateAdmVoteForAddress(vote)) {
-            const res = await get(nodeManager)('/accounts', { address: voteName });
+            const res = await get(nodeManager)('/accounts', {address: voteName});
 
             if (res.success) {
               const publicKey = res.data.account.publicKey;
@@ -57,7 +57,7 @@ module.exports = (nodeManager) => {
               return validator.badParameter('votes');
             }
           } else if (validator.validateAdmVoteForDelegateName(vote)) {
-            const res = await get(nodeManager)('/delegates/get', { username: voteName });
+            const res = await get(nodeManager)('/delegates/get', {username: voteName});
 
             if (res.success) {
               const publicKey = res.data.delegate.publicKey;
@@ -92,7 +92,7 @@ module.exports = (nodeManager) => {
 
       transaction = transactionFormer.createTransaction(type, data);
     } catch (error) {
-      return validator.badParameter('#exception_catched#', error)
+      return validator.badParameter('#exception_catched#', error);
     }
 
     const url = nodeManager.node() + '/api/accounts/delegates';
@@ -101,21 +101,21 @@ module.exports = (nodeManager) => {
       const response = await axios.post(url, transaction);
 
       return validator.formatRequestResults(response, true);
-    } catch(error) {
+    } catch (error) {
       const logMessage = `[ADAMANT js-api] Vote for delegate request: Request to ${url} failed with ${error.response ? error.response.status : undefined} status code, ${error.toString()}${error.response && error.response.data ? '. Message: ' + error.response.data.toString().trim() : ''}. Try ${retryNo+1} of ${maxRetries+1}.`;
 
       if (retryNo < maxRetries) {
         logger.log(`${logMessage} Retrying…`);
 
         return nodeManager.changeNodes()
-          .then(() => (
-            module.exports(nodeManager)(passPhrase, addressOrPublicKey, amount, isAmountInADM, maxRetries, ++retryNo)
-          ));
+            .then(() => (
+              module.exports(nodeManager)(passPhrase, votes, maxRetries, ++retryNo)
+            ));
       }
 
       logger.warn(`${logMessage} No more attempts, returning error.`);
 
       return validator.formatRequestResults(error, false);
     }
-  }
+  };
 };
diff --git a/src/helpers/axiosClient.js b/src/helpers/axiosClient.js
new file mode 100644
index 0000000..d002737
--- /dev/null
+++ b/src/helpers/axiosClient.js
@@ -0,0 +1,4 @@
+const axios = require('axios');
+
+const axiosClient = axios.create();
+module.exports = axiosClient;
diff --git a/src/helpers/bignumber.js b/src/helpers/bignumber.js
new file mode 100644
index 0000000..3d03e46
--- /dev/null
+++ b/src/helpers/bignumber.js
@@ -0,0 +1,125 @@
+/* eslint-disable no-redeclare */
+'use strict';
+
+/**
+  * Buffer functions that implements bignumber.
+  * @memberof module:helpers
+  * @requires bignumber
+  * @constructor
+*/
+const BigNumber = require('bignumber.js');
+
+/**
+  * Creates an instance from a Buffer.
+  * @param {ArrayBuffer} buf
+  * @param {Object} opts
+  * @return {ArrayBuffer} new BigNumber instance
+  * @throws {RangeError} error description multiple of size
+*/
+BigNumber.fromBuffer = function(buf, opts) {
+  if (!opts) opts = {};
+
+  const endian = {1: 'big', '-1': 'little'}[opts.endian] || opts.endian || 'big';
+
+  const size = opts.size === 'auto' ? Math.ceil(buf.length) : (opts.size || 1);
+
+  if (buf.length % size !== 0) {
+    throw new RangeError('Buffer length (' + buf.length + ')' +
+      ' must be a multiple of size (' + size + ')',
+    );
+  }
+
+  const hex = [];
+  for (let i = 0; i < buf.length; i += size) {
+    const chunk = [];
+    for (let j = 0; j < size; j++) {
+      chunk.push(buf[i + (endian === 'big' ? j : (size - j - 1))]);
+    }
+
+    hex.push(chunk
+        .map(function(c) {
+          return (c < 16 ? '0' : '') + c.toString(16);
+        })
+        .join(''),
+    );
+  }
+
+  return new BigNumber(hex.join(''), 16);
+};
+
+/**
+  * Returns an instance as Buffer.
+  * @param {Object} opts
+  * @return {ArrayBuffer} new buffer | error message invalid option
+*/
+BigNumber.prototype.toBuffer = function(opts) {
+  if (typeof opts === 'string') {
+    if (opts !== 'mpint') {
+      return 'Unsupported Buffer representation';
+    }
+
+    const abs = this.abs();
+    const buf = abs.toBuffer({size: 1, endian: 'big'});
+
+    let len = buf.length === 1 && buf[0] === 0 ? 0 : buf.length;
+
+    if (buf[0] & 0x80) len++;
+
+    const ret = Buffer.alloc(4 + len);
+    if (len > 0) buf.copy(ret, 4 + (buf[0] & 0x80 ? 1 : 0));
+    if (buf[0] & 0x80) ret[4] = 0;
+
+    ret[0] = len & (0xff << 24);
+    ret[1] = len & (0xff << 16);
+    ret[2] = len & (0xff << 8);
+    ret[3] = len & (0xff << 0);
+
+    // Two's compliment for negative integers
+    const isNeg = this.lt(0);
+    if (isNeg) {
+      for (let i = 4; i < ret.length; i++) {
+        ret[i] = 0xff - ret[i];
+      }
+    }
+    ret[4] = (ret[4] & 0x7f) | (isNeg ? 0x80 : 0);
+    if (isNeg) ret[ret.length - 1]++;
+
+    return ret;
+  }
+
+  if (!opts) {
+    opts = {};
+  }
+
+  const endian = {1: 'big', '-1': 'little'}[opts.endian] || opts.endian || 'big';
+
+  let hex = this.toString(16);
+  if (hex.charAt(0) === '-') {
+    throw new Error(
+        'Converting negative numbers to Buffers not supported yet',
+    );
+  }
+
+  const size = opts.size === 'auto' ? Math.ceil(hex.length / 2) : (opts.size || 1);
+
+  const len = Math.ceil(hex.length / (2 * size)) * size;
+  const buf = Buffer.alloc(len);
+
+  // Zero-pad the hex string so the chunks are all `size` long
+  while (hex.length < 2 * len) hex = '0' + hex;
+
+  const hx = hex
+      .split(new RegExp('(.{' + (2 * size) + '})'))
+      .filter((s) => s.length > 0);
+
+  hx.forEach((chunk, i) => {
+    for (let j = 0; j < size; j++) {
+      const ix = i * size + (endian === 'big' ? j : size - j - 1);
+      buf[ix] = parseInt(chunk.slice(j * 2, j * 2 + 2), 16);
+    }
+  });
+
+  return buf;
+};
+
+module.exports = BigNumber;
diff --git a/src/helpers/constants.js b/src/helpers/constants.js
new file mode 100644
index 0000000..9af3e15
--- /dev/null
+++ b/src/helpers/constants.js
@@ -0,0 +1,46 @@
+module.exports = {
+
+  epochTime: new Date(Date.UTC(2017, 8, 2, 17, 0, 0, 0)),
+  fees: {
+    send: 50000000,
+    vote: 1000000000,
+    secondsignature: 500000000,
+    delegate: 30000000000,
+    multisignature: 500000000,
+    dapp: 2500000000,
+    old_chat_message: 500000,
+    chat_message: 100000,
+    profile_update: 5000000,
+    avatar_upload: 10000000,
+    state_store: 100000,
+  },
+  transactionTypes: {
+    SEND: 0,
+    SIGNATURE: 1,
+    DELEGATE: 2,
+    VOTE: 3,
+    MULTI: 4,
+    DAPP: 5,
+    IN_TRANSFER: 6,
+    OUT_TRANSFER: 7,
+    CHAT_MESSAGE: 8,
+    STATE: 9,
+  },
+  maxVotesPerTransaction: 33,
+  SAT: 100000000,
+  RE_HEX: /^[a-fA-F0-9]+$/,
+  RE_BASE64: /^([A-Za-z0-9+/]{4})*([A-Za-z0-9+/]{4}|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{2}==)$/,
+  RE_ADM_ADDRESS: /^U([0-9]{6,})$/,
+  RE_ADM_VOTE_FOR_PUBLIC_KEY: /^(\+|-)[a-fA-F0-9]{64}$/,
+  RE_ADM_VOTE_FOR_ADDRESS: /^(\+|-)U([0-9]{6,})$/,
+  RE_ADM_VOTE_FOR_DELEGATE_NAME: /^(\+|-)([a-z0-9!@$&_]{1,20})$/,
+  RE_ADM_DELEGATE_NAME: /^[a-z0-9!@$&_]{1,20}$/,
+  RE_BTC_ADDRESS: /^(bc1|[13])[a-km-zA-HJ-NP-Z02-9]{25,39}$/,
+  RE_DASH_ADDRESS: /^[7X][1-9A-HJ-NP-Za-km-z]{33,}$/,
+  RE_DOGE_ADDRESS: /^[A|D|9][A-Z0-9]([0-9a-zA-Z]{9,})$/,
+  RE_LSK_ADDRESS: /^[0-9]{2,21}L$/,
+
+  RE_HTTP_URL: /^https?:\/\/(.*)$/,
+  RE_IP: /(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}/,
+
+};
diff --git a/src/helpers/encryptor.js b/src/helpers/encryptor.js
new file mode 100644
index 0000000..265c64e
--- /dev/null
+++ b/src/helpers/encryptor.js
@@ -0,0 +1,42 @@
+const sodium = require('sodium-browserify-tweetnacl');
+const nacl = require('tweetnacl/nacl-fast');
+const ed2curve = require('ed2curve');
+
+module.exports = {
+  bytesToHex(bytes) {
+    let hex = '';
+
+    for (const byte of bytes) {
+      hex += (byte >>> 4).toString(16);
+      hex += (byte & 0xF).toString(16);
+    }
+
+    return hex;
+  },
+  hexToBytes(hex) {
+    const bytes = [];
+
+    for (let c = 0; c < hex.length; c += 2) {
+      bytes.push(parseInt(hex.substr(c, 2), 16));
+    }
+
+    return bytes;
+  },
+  encodeMessage(msg, keypair, recipientPublicKey) {
+    const nonce = Buffer.allocUnsafe(24);
+    sodium.randombytes(nonce);
+
+    const plainText = Buffer.from(msg.toString());
+    const DHSecretKey = ed2curve.convertSecretKey(keypair.privateKey);
+    const DHPublicKey = ed2curve.convertPublicKey(
+        new Uint8Array(this.hexToBytes(recipientPublicKey)),
+    );
+
+    const encrypted = nacl.box(plainText, nonce, DHPublicKey, DHSecretKey);
+
+    return {
+      message: this.bytesToHex(encrypted),
+      own_message: this.bytesToHex(nonce),
+    };
+  },
+};
diff --git a/src/helpers/healthCheck.js b/src/helpers/healthCheck.js
new file mode 100644
index 0000000..c471138
--- /dev/null
+++ b/src/helpers/healthCheck.js
@@ -0,0 +1,211 @@
+const dnsPromises = require('dns').promises;
+
+const axios = require('../helpers/axiosClient');
+const socket = require('./wsClient');
+const logger = require('./logger');
+const validator = require('./validator');
+
+const {RE_IP, RE_HTTP_URL} = require('./constants');
+
+const CHECK_NODES_INTERVAL = 60 * 5 * 1000; // Update active nodes every 5 minutes
+const HEIGHT_EPSILON = 5; // Used to group nodes by height and choose synced
+
+module.exports = (nodes, checkHealthAtStartup = true) => {
+  const nodesList = nodes;
+  let isCheckingNodes = false;
+
+  // Note: it may be not synced; and before first health check a node can reply with obsolete data
+  let [activeNode] = nodesList;
+
+  /**
+    * Updates active nodes. If nodes are already updating, returns Promise of previous call
+    * @param {boolean} isPlannedUpdate
+    * @return {Promise} Call changeNodes().then to do something when update complete
+    */
+  async function changeNodes(isPlannedUpdate = false) {
+    if (!isCheckingNodes) {
+      if (!isPlannedUpdate) {
+        logger.warn('[ADAMANT js-api] Health check: Forcing to update active nodes…');
+      }
+
+      await checkNodes(!isPlannedUpdate);
+
+      return true;
+    }
+  }
+
+  /**
+    * Requests every ADAMANT node for its status, makes a list of live nodes, and chooses one active
+    * @param {boolean} forceChangeActiveNode
+    */
+  async function checkNodes(forceChangeActiveNode) {
+    isCheckingNodes = true;
+
+    const liveNodes = [];
+
+    try {
+      for (const node of nodesList) {
+        try {
+          const start = unixTimestamp();
+
+          const req = await checkNode(`${node}/api/node/status`);
+
+          const [url] = node.replace(RE_HTTP_URL, '$1').split(':');
+          const ifIP = RE_IP.test(url);
+
+          const ip = ifIP ? url : await getIP(url);
+          const ifHttps = node.startsWith('https');
+
+          if (req.status) {
+            liveNodes.push({
+              node,
+              ifIP,
+              url,
+              ip,
+              ifHttps,
+              outOfSync: false,
+              ping: unixTimestamp() - start,
+              height: req.status.network.height,
+              heightEpsilon: Math.round(req.status.network.height / HEIGHT_EPSILON),
+              socketSupport: req.status.wsClient?.enabled,
+              wsPort: req.status.wsClient?.port,
+            });
+          } else {
+            logger.log(`[ADAMANT js-api] Health check: Node ${node} haven't returned its status`);
+          }
+        } catch (e) {
+          logger.log(`[ADAMANT js-api] Health check: Error while checking node ${node}, ${e}`);
+        }
+      }
+
+      const count = liveNodes.length;
+
+      let outOfSyncCount = 0;
+
+      if (!count) {
+        logger.error(`[ADAMANT js-api] Health check: All of ${nodesList.length} nodes are unavailable. Check internet connection and nodes list in config.`);
+      } else {
+        // Set activeNode to one that have maximum height and minimum ping
+        if (count === 1) {
+          activeNode = liveNodes[0].node;
+        } else if (count === 2) {
+          const [h0, h1] = liveNodes;
+
+          activeNode = h0.height > h1.height ? h0.node : h1.node;
+
+          // Mark node outOfSync if needed
+          if (h0.heightEpsilon > h1.heightEpsilon) {
+            liveNodes[1].outOfSync = true;
+            outOfSyncCount += 1;
+          } else if (h0.heightEpsilon < h1.heightEpsilon) {
+            liveNodes[0].outOfSync = true;
+            outOfSyncCount += 1;
+          }
+        } else {
+          let biggestGroup = [];
+          // Removing lodash: const groups = _.groupBy(liveNodes, n => n.heightEpsilon);
+          const groups = liveNodes.reduce((grouped, node) => {
+            const int = Math.floor(node.heightEpsilon); // Excessive, it is already rounded
+
+            if (!Object.prototype.hasOwnProperty.call(grouped, int)) {
+              grouped[int] = [];
+            }
+
+            grouped[int].push(node);
+
+            return grouped;
+          }, {});
+
+          Object.keys(groups).forEach((key) => {
+            if (groups[key].length > biggestGroup.length) {
+              biggestGroup = groups[key];
+            }
+          });
+
+          // All the nodes from the biggestGroup list are considered to be in sync, all the others are not
+          liveNodes.forEach((node) => {
+            node.outOfSync = !biggestGroup.includes(node);
+          });
+
+          outOfSyncCount = liveNodes.length - biggestGroup.length;
+
+          biggestGroup.sort((a, b) => a.ping - b.ping);
+          liveNodes.sort((a, b) => a.ping - b.ping);
+
+          if (forceChangeActiveNode && biggestGroup.length > 1 && activeNode === biggestGroup[0].node) {
+            // Use random node from which are synced
+            activeNode = biggestGroup[validator.getRandomIntInclusive(1, biggestGroup.length - 1)].node;
+          } else {
+            // Use node with minimum ping among which are synced
+            activeNode = biggestGroup[0].node;
+          }
+        }
+
+        socket.reviseConnection(liveNodes);
+
+        const unavailableCount = nodesList.length - liveNodes.length;
+        const supportedCount = liveNodes.length - outOfSyncCount;
+
+        let nodesInfoString = '';
+
+        if (unavailableCount) {
+          nodesInfoString += `, ${unavailableCount} nodes didn't respond`;
+        }
+
+        if (outOfSyncCount) {
+          nodesInfoString += `, ${outOfSyncCount} nodes are not synced`;
+        }
+
+        logger.log(`[ADAMANT js-api] Health check: Found ${supportedCount} supported and synced nodes${nodesInfoString}. Active node is ${activeNode}.`);
+      }
+    } catch (e) {
+      logger.warn('[ADAMANT js-api] Health check: Error in checkNodes(), ' + e);
+    }
+
+    isCheckingNodes = false;
+  }
+
+  if (checkHealthAtStartup) {
+    changeNodes(true);
+
+    setInterval(
+        () => changeNodes(true),
+        CHECK_NODES_INTERVAL,
+    );
+  }
+
+  return {
+    /**
+     * @return {string} Current active node, f. e. http://88.198.156.44:36666
+     */
+    node: () => activeNode,
+    changeNodes,
+  };
+};
+
+async function getIP(url) {
+  try {
+    const addresses = await dnsPromises.resolve4(url);
+
+    if (addresses && addresses[0] !== '0.0.0.0') {
+      return addresses[0];
+    }
+  } catch (error) {
+    return;
+  }
+}
+
+/**
+  * Requests status from a single ADAMANT node
+  * @param {string} url Node URL to request
+  * @return {Promise} Node's status information
+  */
+function checkNode(url) {
+  return axios.get(url)
+      .then((response) => ({status: response.data}))
+      .catch((err) => false);
+}
+
+function unixTimestamp() {
+  return new Date().getTime();
+}
diff --git a/src/helpers/keys.js b/src/helpers/keys.js
new file mode 100644
index 0000000..9df0573
--- /dev/null
+++ b/src/helpers/keys.js
@@ -0,0 +1,49 @@
+const sodium = require('sodium-browserify-tweetnacl');
+const crypto = require('crypto');
+const Mnemonic = require('bitcore-mnemonic');
+
+const bignum = require('./bignumber.js');
+
+module.exports = {
+  createNewPassPhrase() {
+    return new Mnemonic(Mnemonic.Words.ENGLISH).toString();
+  },
+  makeKeypairFromHash(hash) {
+    const keypair = sodium.crypto_sign_seed_keypair(hash);
+
+    return {
+      publicKey: keypair.publicKey,
+      privateKey: keypair.secretKey,
+    };
+  },
+  createHashFromPassPhrase(passPhrase) {
+    const secretMnemonic = new Mnemonic(passPhrase, Mnemonic.Words.ENGLISH);
+
+    return crypto
+        .createHash('sha256')
+        .update(
+            secretMnemonic.toSeed().toString('hex'),
+            'hex',
+        )
+        .digest();
+  },
+  createKeypairFromPassPhrase(passPhrase) {
+    const hash = this.createHashFromPassPhrase(passPhrase);
+
+    return this.makeKeypairFromHash(hash);
+  },
+  createAddressFromPublicKey(publicKey) {
+    const publicKeyHash = crypto
+        .createHash('sha256')
+        .update(publicKey, 'hex')
+        .digest();
+
+    const temp = Buffer.alloc(8);
+
+    for (let i = 0; i < 8; i++) {
+      temp[i] = publicKeyHash[7 - i];
+    }
+
+    return `U${bignum.fromBuffer(temp)}`;
+  },
+};
diff --git a/src/helpers/logger.js b/src/helpers/logger.js
new file mode 100644
index 0000000..4278e1e
--- /dev/null
+++ b/src/helpers/logger.js
@@ -0,0 +1,36 @@
+const logger = {
+  errorLevel: 'log',
+  logger: console,
+
+  initLogger(errorLevel, log) {
+    if (errorLevel) {
+      this.errorLevel = errorLevel;
+    }
+
+    if (log) {
+      this.logger = log;
+    }
+  },
+  error(str) {
+    if (['error', 'warn', 'info', 'log'].includes(this.errorLevel)) {
+      this.logger.error(str);
+    }
+  },
+  warn(str) {
+    if (['warn', 'info', 'log'].includes(this.errorLevel)) {
+      this.logger.warn(str);
+    }
+  },
+  info(str) {
+    if (['info', 'log'].includes(this.errorLevel)) {
+      this.logger.info(str);
+    }
+  },
+  log(str) {
+    if (this.errorLevel === 'log') {
+      this.logger.log(str);
+    }
+  },
+};
+
+module.exports = logger;
diff --git a/src/helpers/tests/keys.test.js b/src/helpers/tests/keys.test.js
new file mode 100644
index 0000000..eb4ee6d
--- /dev/null
+++ b/src/helpers/tests/keys.test.js
@@ -0,0 +1,62 @@
+const keys = require('../keys');
+const {validateAdmAddress} = require('../validator');
+
+describe('createNewPassPhrase', () => {
+  test('Should return string that contains more than 11 words', () => {
+    const passPhrase = keys.createNewPassPhrase();
+
+    expect(typeof passPhrase).toBe('string');
+    expect(
+        passPhrase.split(' ').length,
+    ).toBeGreaterThanOrEqual(12);
+  });
+});
+
+describe('makeKeypairFromHash', () => {
+  test('Should return object with buffers publicKey and privateKey', () => {
+    const passPhrase = keys.createNewPassPhrase();
+    const hash = keys.createHashFromPassPhrase(passPhrase);
+
+    const keypair = keys.makeKeypairFromHash(hash);
+
+    expect(typeof keypair).toBe('object');
+
+    expect(Buffer.isBuffer(keypair.publicKey)).toBe(true);
+    expect(Buffer.isBuffer(keypair.privateKey)).toBe(true);
+  });
+});
+
+describe('createHashFromPassPhrase', () => {
+  test('Should return different hashes for different passPhrases', () => {
+    const passPhrase = keys.createNewPassPhrase();
+    const passPhrase2 = keys.createNewPassPhrase();
+
+    const hash = keys.createHashFromPassPhrase(passPhrase);
+    const hash2 = keys.createHashFromPassPhrase(passPhrase2);
+
+    expect(hash.equals(hash2)).toBe(false);
+  });
+});
+
+describe('createKeypairFromPassPhrase', () => {
+  test('Should return keypair with publicKey and privateKey', () => {
+    const passPhrase = keys.createNewPassPhrase();
+    const keypair = keys.createKeypairFromPassPhrase(passPhrase);
+
+    expect(typeof keypair).toBe('object');
+
+    expect(Buffer.isBuffer(keypair.publicKey)).toBe(true);
+    expect(Buffer.isBuffer(keypair.privateKey)).toBe(true);
+  });
+});
+
+describe('createAddressFromPublicKey', () => {
+  test('Should return a string which matches the address pattern', () => {
+    const passPhrase = keys.createNewPassPhrase();
+    const keypair = keys.createKeypairFromPassPhrase(passPhrase);
+
+    const address = keys.createAddressFromPublicKey(keypair.publicKey);
+
+    expect(validateAdmAddress(address)).toBe(true);
+  });
+});
diff --git a/src/helpers/tests/logger.test.js b/src/helpers/tests/logger.test.js
new file mode 100644
index 0000000..a463297
--- /dev/null
+++ b/src/helpers/tests/logger.test.js
@@ -0,0 +1,203 @@
+const logger = require('../logger');
+
+describe('logger: log', () => {
+  const logLevel = 'log';
+
+  test('Should log log level', (done) => {
+    logger.initLogger(logLevel, {
+      log(str) {
+        expect(str).toBe('log');
+
+        done();
+      },
+    });
+
+    logger.log('log');
+  });
+
+  test('Should log info level', (done) => {
+    logger.initLogger(logLevel, {
+      info(str) {
+        expect(str).toBe('info');
+
+        done();
+      },
+    });
+
+    logger.info('info');
+  });
+
+  test('Should log warn level', (done) => {
+    logger.initLogger(logLevel, {
+      warn(str) {
+        expect(str).toBe('warn');
+
+        done();
+      },
+    });
+
+    logger.warn('warn');
+  });
+
+  test('Should log error level', (done) => {
+    logger.initLogger(logLevel, {
+      error(str) {
+        expect(str).toBe('error');
+
+        done();
+      },
+    });
+
+    logger.error('error');
+  });
+});
+
+describe('logger: info', () => {
+  const logLevel = 'info';
+
+  test('Should not log log level', (done) => {
+    logger.initLogger(logLevel, {
+      log() {
+        done('Log level has been called');
+      },
+    });
+
+    logger.log('log');
+    done();
+  });
+
+  test('Should log info level', (done) => {
+    logger.initLogger(logLevel, {
+      info(str) {
+        expect(str).toBe('info');
+
+        done();
+      },
+    });
+
+    logger.info('info');
+  });
+
+  test('Should log warn level', (done) => {
+    logger.initLogger(logLevel, {
+      warn(str) {
+        expect(str).toBe('warn');
+
+        done();
+      },
+    });
+
+    logger.warn('warn');
+  });
+
+  test('Should log error level', (done) => {
+    logger.initLogger(logLevel, {
+      error(str) {
+        expect(str).toBe('error');
+
+        done();
+      },
+    });
+
+    logger.error('error');
+  });
+});
+
+describe('logger: warn', () => {
+  const logLevel = 'warn';
+
+  test('Should not log log level', (done) => {
+    logger.initLogger(logLevel, {
+      log() {
+        done('Log level has been called');
+      },
+    });
+
+    logger.log('log');
+    done();
+  });
+
+  test('Should not log info level', (done) => {
+    logger.initLogger(logLevel, {
+      info() {
+        done('Info level has been called');
+      },
+    });
+
+    logger.info('info');
+    done();
+  });
+
+  test('Should log warn level', (done) => {
+    logger.initLogger(logLevel, {
+      warn(str) {
+        expect(str).toBe('warn');
+
+        done();
+      },
+    });
+
+    logger.warn('warn');
+  });
+
+  test('Should log error level', (done) => {
+    logger.initLogger(logLevel, {
+      error(str) {
+        expect(str).toBe('error');
+
+        done();
+      },
+    });
+
+    logger.error('error');
+  });
+});
+
+describe('logger: error', () => {
+  const logLevel = 'error';
+
+  test('Should not log log level', (done) => {
+    logger.initLogger(logLevel, {
+      log() {
+        done('Log level has been called');
+      },
+    });
+
+    logger.log('log');
+    done();
+  });
+
+  test('Should not log info level', (done) => {
+    logger.initLogger(logLevel, {
+      info() {
+        done('Info level has been called');
+      },
+    });
+
+    logger.info('info');
+    done();
+  });
+
+  test('Should not log warn level', (done) => {
+    logger.initLogger(logLevel, {
+      warn() {
+        done('Warn level has been called');
+      },
+    });
+
+    logger.warn('warn');
+    done();
+  });
+
+  test('Should log error level', (done) => {
+    logger.initLogger(logLevel, {
+      error(str) {
+        expect(str).toBe('error');
+
+        done();
+      },
+    });
+
+    logger.error('error');
+  });
+});
diff --git a/src/helpers/tests/time.test.js b/src/helpers/tests/time.test.js
new file mode 100644
index 0000000..48319a8
--- /dev/null
+++ b/src/helpers/tests/time.test.js
@@ -0,0 +1,10 @@
+const time = require('../time');
+const {epochTime} = require('../constants');
+
+describe('getTime', () => {
+  test('Should return 0 for epoch time', () => {
+    expect(
+        time.getTime(epochTime.getTime()),
+    ).toBe(0);
+  });
+});
diff --git a/src/helpers/tests/transactionFormer.test.js b/src/helpers/tests/transactionFormer.test.js
new file mode 100644
index 0000000..2e4e12b
--- /dev/null
+++ b/src/helpers/tests/transactionFormer.test.js
@@ -0,0 +1,171 @@
+const transactionFormer = require('../transactionFormer');
+const keys = require('../keys');
+const constants = require('../constants');
+
+const passPhrase = keys.createNewPassPhrase();
+const keyPair = keys.createKeypairFromPassPhrase(passPhrase);
+
+describe('Create send transaction', () => {
+  const transactionType = constants.transactionTypes.SEND;
+
+  test('Should create base transaction', () => {
+    const data = {
+      keyPair,
+      recipientId: 'U123456',
+      amount: 1,
+    };
+
+    const transaction = transactionFormer.createTransaction(transactionType, data);
+
+    expect(transaction).toMatchObject({
+      type: transactionType,
+      amount: 1,
+      recipientId: 'U123456',
+    });
+    expect(transaction).toHaveProperty('timestamp');
+    expect(transaction).toHaveProperty('senderPublicKey');
+    expect(transaction).toHaveProperty('senderId');
+    expect(transaction).toHaveProperty('asset');
+    expect(transaction).toHaveProperty('signature');
+    expect(
+        typeof transaction.signature,
+    ).toBe('string');
+  });
+});
+
+describe('Create vote transaction', () => {
+  const transactionType = constants.transactionTypes.VOTE;
+
+  test('Should create base transaction', () => {
+    const data = {
+      keyPair,
+      votes: [],
+    };
+
+    const transaction = transactionFormer.createTransaction(transactionType, data);
+
+    expect(transaction).toMatchObject({
+      type: transactionType,
+      amount: 0,
+    });
+    expect(transaction).toHaveProperty('timestamp');
+    expect(transaction).toHaveProperty('recipientId');
+    expect(transaction).toHaveProperty('senderPublicKey');
+    expect(transaction).toHaveProperty('senderId');
+    expect(transaction).toHaveProperty('asset');
+    expect(transaction).toHaveProperty('signature');
+    expect(
+        typeof transaction.signature,
+    ).toBe('string');
+  });
+});
+
+describe('Create delegate transaction', () => {
+  const transactionType = constants.transactionTypes.DELEGATE;
+  const username = 'admtest';
+
+  test('Should create base transaction', () => {
+    const data = {
+      keyPair,
+      username,
+    };
+
+    const transaction = transactionFormer.createTransaction(transactionType, data);
+
+    expect(transaction).toMatchObject({
+      type: transactionType,
+      amount: 0,
+      asset: {
+        delegate: {
+          username,
+        },
+      },
+    });
+    expect(transaction).toHaveProperty('timestamp');
+    expect(transaction).toHaveProperty('senderPublicKey');
+    expect(transaction).toHaveProperty('senderId');
+    expect(transaction).toHaveProperty('asset');
+    expect(transaction).toHaveProperty('recipientId');
+    expect(transaction).toHaveProperty('asset.delegate.publicKey');
+    expect(transaction).toHaveProperty('signature');
+    expect(
+        typeof transaction.signature,
+    ).toBe('string');
+  });
+});
+
+describe('Create chat transaction', () => {
+  const transactionType = constants.transactionTypes.CHAT_MESSAGE;
+
+  test('Should create base transaction', () => {
+    const data = {
+      keyPair,
+      amount: 1,
+      message: 'Hello!',
+      own_message: null,
+      message_type: 0,
+      recipientId: 'U123456',
+    };
+
+    const transaction = transactionFormer.createTransaction(transactionType, data);
+
+    expect(transaction).toMatchObject({
+      type: transactionType,
+      recipientId: data.recipientId,
+      amount: 1,
+      asset: {
+        chat: {
+          message: data.message,
+          own_message: data.own_message,
+          type: data.message_type,
+        },
+      },
+    });
+    expect(transaction).toHaveProperty('timestamp');
+    expect(transaction).toHaveProperty('senderPublicKey');
+    expect(transaction).toHaveProperty('senderId');
+    expect(transaction).toHaveProperty('asset');
+    expect(transaction).toHaveProperty('recipientId');
+    expect(transaction).toHaveProperty('signature');
+    expect(
+        typeof transaction.signature,
+    ).toBe('string');
+  });
+});
+
+describe('Create state transaction', () => {
+  const transactionType = constants.transactionTypes.STATE;
+
+  test('Should create base transaction', () => {
+    const data = {
+      keyPair,
+      key: 'key',
+      value: 'value',
+    };
+
+    const transaction = transactionFormer.createTransaction(transactionType, data);
+
+    expect(transaction).toMatchObject({
+      type: transactionType,
+      recipientId: null,
+      amount: 0,
+      asset: {
+        state: {
+          key: data.key,
+          value: data.value,
+          type: 0,
+        },
+      },
+    });
+    expect(transaction).toHaveProperty('timestamp');
+    expect(transaction).toHaveProperty('senderPublicKey');
+    expect(transaction).toHaveProperty('senderId');
+    expect(transaction).toHaveProperty('asset');
+    expect(transaction).toHaveProperty('recipientId');
+    expect(transaction).toHaveProperty('signature');
+    expect(
+        typeof transaction.signature,
+    ).toBe('string');
+  });
+});
+
diff --git a/src/helpers/tests/validator.test.js b/src/helpers/tests/validator.test.js
new file mode 100644
index 0000000..e9d211f
--- /dev/null
+++ b/src/helpers/tests/validator.test.js
@@ -0,0 +1,321 @@
+const validator = require('../validator');
+
+describe('isNumeric', () => {
+  test('Should return false for a number', () => {
+    expect(validator.isNumeric(3)).toBe(false);
+  });
+
+  test('Should return false for Infinity', () => {
+    expect(validator.isNumeric(Infinity)).toBe(false);
+  });
+
+  test('Should return false for an object', () => {
+    expect(validator.isNumeric({})).toBe(false);
+  });
+
+  test('Should return false for undefined', () => {
+    expect(validator.isNumeric(undefined)).toBe(false);
+  });
+
+  test('Should return false for NaN', () => {
+    expect(validator.isNumeric(undefined)).toBe(false);
+  });
+
+  test('Should return false for `n3.14`', () => {
+    expect(validator.isNumeric('n3.14')).toBe(false);
+  });
+
+  test('Should return false for `3,14`', () => {
+    expect(validator.isNumeric('3,14')).toBe(true);
+  });
+
+  test('Should return true for `3.14`', () => {
+    expect(validator.isNumeric('3.14')).toBe(true);
+  });
+
+  test('Should return true for ` 3.14`', () => {
+    expect(validator.isNumeric(' 3.14')).toBe(true);
+  });
+});
+
+describe('validatePassPhrase', () => {
+  test('Should return false for a number', () => {
+    expect(validator.validatePassPhrase(3)).toBe(false);
+  });
+
+  test('Should return false for an object', () => {
+    expect(validator.validatePassPhrase({})).toBe(false);
+  });
+
+  test('Should return false for undefined', () => {
+    expect(validator.validatePassPhrase(undefined)).toBe(false);
+  });
+
+  test('Should return false for NaN', () => {
+    expect(validator.validatePassPhrase(undefined)).toBe(false);
+  });
+
+  test('Should return false for a too short string', () => {
+    expect(validator.validatePassPhrase('short')).toBe(false);
+  });
+
+  test('Should return true for a long string', () => {
+    expect(validator.validatePassPhrase('word '.repeat(12))).toBe(true);
+  });
+});
+
+describe('validateAdmAddress', () => {
+  test('Should return false for a number', () => {
+    expect(validator.validateAdmAddress(3)).toBe(false);
+  });
+
+  test('Should return false for an object', () => {
+    expect(validator.validateAdmAddress({})).toBe(false);
+  });
+
+  test('Should return false for undefined', () => {
+    expect(validator.validateAdmAddress(undefined)).toBe(false);
+  });
+
+  test('Should return false for NaN', () => {
+    expect(validator.validateAdmAddress(undefined)).toBe(false);
+  });
+
+  test('Should return false for U123', () => {
+    expect(validator.validateAdmAddress('U123')).toBe(false);
+  });
+
+  test('Should return false for ` U123456`', () => {
+    expect(validator.validateAdmAddress(' U123456')).toBe(false);
+  });
+
+  test('Should return false for `U123213N123`', () => {
+    expect(validator.validateAdmAddress('U123213N123')).toBe(false);
+  });
+
+  test('Should return true for U123456', () => {
+    expect(validator.validateAdmAddress('U1234506')).toBe(true);
+  });
+
+  test('Should return true for U01234561293812931283918239', () => {
+    expect(validator.validateAdmAddress('U01234561293812931283918239')).toBe(true);
+  });
+});
+
+describe('validateAdmPublicKey', () => {
+  test('Should return false for a number', () => {
+    expect(validator.validateAdmPublicKey(3)).toBe(false);
+  });
+
+  test('Should return false for an object', () => {
+    expect(validator.validateAdmPublicKey({})).toBe(false);
+  });
+
+  test('Should return false for undefined', () => {
+    expect(validator.validateAdmPublicKey(undefined)).toBe(false);
+  });
+
+  test('Should return false for NaN', () => {
+    expect(validator.validateAdmPublicKey(undefined)).toBe(false);
+  });
+
+  test('Should return false for a short string', () => {
+    expect(validator.validateAdmPublicKey('0f')).toBe(false);
+  });
+
+  test('Should return false for a string that contains `L`', () => {
+    expect(validator.validateAdmPublicKey('Le003f782cd1c1c84a6767a871321af2ecdb3da8d8f6b8d1f13179835b6ec432')).toBe(false);
+  });
+
+  test('Should return true for a public key that starts with a number', () => {
+    expect(validator.validateAdmPublicKey('4e003f782cd1c1c84A6767a871321af2ecdb3da8d8f6b8d1f13179835b6ec432')).toBe(true);
+  });
+
+  test('Should return true for a public key that starts with a letter', () => {
+    expect(validator.validateAdmPublicKey('e4003f782cd1c1c84A6767a871321af2ecdb3da8d8f6b8d1f13179835b6ec432')).toBe(true);
+  });
+});
+
+describe('validateAdmVoteForAddress', () => {
+  test('Should return false for a number', () => {
+    expect(validator.validateAdmVoteForAddress(3)).toBe(false);
+  });
+
+  test('Should return false for an object', () => {
+    expect(validator.validateAdmVoteForAddress({})).toBe(false);
+  });
+
+  test('Should return false for undefined', () => {
+    expect(validator.validateAdmVoteForAddress(undefined)).toBe(false);
+  });
+
+  test('Should return false for NaN', () => {
+    expect(validator.validateAdmVoteForAddress(undefined)).toBe(false);
+  });
+
+  test('Should return false for a short string', () => {
+    expect(validator.validateAdmVoteForAddress('0f')).toBe(false);
+  });
+
+  test('Should return false for a string that starts with `L`', () => {
+    expect(validator.validateAdmVoteForAddress('L01234561293812931283918239')).toBe(false);
+  });
+
+  test('Should return false for an address that starts with a number', () => {
+    expect(validator.validateAdmVoteForAddress('0U1234561293812931283918239')).toBe(false);
+  });
+
+  test('Should return false for an address that starts with a letter', () => {
+    expect(validator.validateAdmVoteForAddress('U01234561293812931283918239')).toBe(false);
+  });
+
+  test('Should return true for an address with a plus', () => {
+    expect(validator.validateAdmVoteForAddress('+U01234561293812931283918239')).toBe(true);
+  });
+
+  test('Should return true for an address with a minus', () => {
+    expect(validator.validateAdmVoteForAddress('+U01234561293812931283918239')).toBe(true);
+  });
+});
+
+describe('validateAdmVoteForPublicKey', () => {
+  test('Should return false for a number', () => {
+    expect(validator.validateAdmVoteForPublicKey(3)).toBe(false);
+  });
+
+  test('Should return false for an object', () => {
+    expect(validator.validateAdmVoteForPublicKey({})).toBe(false);
+  });
+
+  test('Should return false for undefined', () => {
+    expect(validator.validateAdmVoteForPublicKey(undefined)).toBe(false);
+  });
+
+  test('Should return false for NaN', () => {
+    expect(validator.validateAdmVoteForPublicKey(undefined)).toBe(false);
+  });
+
+  test('Should return false for a short string', () => {
+    expect(validator.validateAdmVoteForPublicKey('0f')).toBe(false);
+  });
+
+  test('Should return false for a string that starts with `L`', () => {
+    expect(validator.validateAdmVoteForPublicKey('+L4e003f782cd1c1c84A6767a871321af2ecdb3da8d8f6b8d1f13179835b6ec432')).toBe(false);
+  });
+
+  test('Should return false for a public key that starts with a number', () => {
+    expect(validator.validateAdmVoteForPublicKey('4e003f782cd1c1c84A6767a871321af2ecdb3da8d8f6b8d1f13179835b6ec432')).toBe(false);
+  });
+
+  test('Should return false for a public key that starts with a letter', () => {
+    expect(validator.validateAdmVoteForPublicKey('e4003f782cd1c1c84A6767a871321af2ecdb3da8d8f6b8d1f13179835b6ec432')).toBe(false);
+  });
+
+  test('Should return true for a public key with a plus', () => {
+    expect(validator.validateAdmVoteForPublicKey('+4e003f782cd1c1c84A6767a871321af2ecdb3da8d8f6b8d1f13179835b6ec432')).toBe(true);
+  });
+
+  test('Should return true for a public key with a minus', () => {
+    expect(validator.validateAdmVoteForPublicKey('+4e003f782cd1c1c84A6767a871321af2ecdb3da8d8f6b8d1f13179835b6ec432')).toBe(true);
+  });
+});
+
+describe('validateAdmVoteForDelegateName', () => {
+  test('Should return false for a number', () => {
+    expect(validator.validateAdmVoteForDelegateName(3)).toBe(false);
+  });
+
+  test('Should return false for an object', () => {
+    expect(validator.validateAdmVoteForDelegateName({})).toBe(false);
+  });
+
+  test('Should return false for undefined', () => {
+    expect(validator.validateAdmVoteForDelegateName(undefined)).toBe(false);
+  });
+
+  test('Should return false for NaN', () => {
+    expect(validator.validateAdmVoteForDelegateName(undefined)).toBe(false);
+  });
+
+  test('Should return false for a short string', () => {
+    expect(validator.validateAdmVoteForDelegateName('0f')).toBe(false);
+  });
+
+  test('Should return false for a vote without delegate name', () => {
+    expect(validator.validateAdmVoteForDelegateName('+')).toBe(false);
+  });
+
+  test('Should return false for a too long delegate name', () => {
+    expect(validator.validateAdmVoteForDelegateName('+e003f782cd1c1c84A6767a871321af2e')).toBe(false);
+  });
+
+  test('Should return false for a vote that starts with a number', () => {
+    expect(validator.validateAdmVoteForDelegateName('4darksinc')).toBe(false);
+  });
+
+  test('Should return false for a vote that starts with a letter', () => {
+    expect(validator.validateAdmVoteForDelegateName('darksinc')).toBe(false);
+  });
+
+  test('Should return true for a delegate name with a plus', () => {
+    expect(validator.validateAdmVoteForDelegateName('+darksinc')).toBe(true);
+  });
+
+  test('Should return true for a delegate name with a minus', () => {
+    expect(validator.validateAdmVoteForDelegateName('+darksinc')).toBe(true);
+  });
+});
+
+describe('validateMessage', () => {
+  test('Result should be false for a number message', () => {
+    expect(validator.validateMessage(3).result).toBe(false);
+  });
+
+  test('Result should be false for an object message', () => {
+    expect(validator.validateMessage({}).result).toBe(false);
+  });
+
+  test('Result should be true for a string message', () => {
+    expect(validator.validateMessage('').result).toBe(true);
+  });
+
+  test('Result should be false for a string rich message', () => {
+    expect(validator.validateMessage('', 2).result).toBe(false);
+  });
+
+  test('Result should be false for a string signal message', () => {
+    expect(validator.validateMessage('', 3).result).toBe(false);
+  });
+
+  test('Result should be false for an empty json rich message', () => {
+    expect(validator.validateMessage('{}', 2).result).toBe(false);
+  });
+
+  test('Result should be false for an empty json signal message', () => {
+    expect(validator.validateMessage('{}', 3).result).toBe(false);
+  });
+
+  test('Result should be true for a json rich message with the given amount', () => {
+    expect(validator.validateMessage('{"amount": "0.13"}', 2).result).toBe(true);
+  });
+
+  test('Result should be true for a json signal message with the given amount', () => {
+    expect(validator.validateMessage('{"amount": "0.13"}', 3).result).toBe(true);
+  });
+
+  test('Result should be false for a json rich message with upercase coin name', () => {
+    expect(validator.validateMessage('{"amount": "0.13", "type": "ETH_transaction"}', 2).result).toBe(false);
+  });
+
+  test('Result should be false for a json signal message with upercase coin name', () => {
+    expect(validator.validateMessage('{"amount": "0.13", "type": "ETH_transaction"}', 3).result).toBe(false);
+  });
+
+  test('Result should be true for a json rich message with lowercase coin name', () => {
+    expect(validator.validateMessage('{"amount": "0.13", "type": "eth_transaction"}', 2).result).toBe(true);
+  });
+
+  test('Result should be true for a json signal message with lowercase coin name', () => {
+    expect(validator.validateMessage('{"amount": "0.13", "type": "eth_transaction"}', 3).result).toBe(true);
+  });
+});
diff --git a/src/helpers/time.js b/src/helpers/time.js
new file mode 100644
index 0000000..4504cac
--- /dev/null
+++ b/src/helpers/time.js
@@ -0,0 +1,15 @@
+const constants = require('./constants.js');
+
+module.exports = {
+  getEpochTime(time) {
+    const startTime = time ?? Date.now();
+
+    const {epochTime} = constants;
+    const epochTimeMs = epochTime.getTime();
+
+    return Math.floor((startTime - epochTimeMs) / 1000);
+  },
+  getTime(time) {
+    return this.getEpochTime(time);
+  },
+};
diff --git a/src/helpers/transactionFormer.js b/src/helpers/transactionFormer.js
new file mode 100644
index 0000000..e03cd91
--- /dev/null
+++ b/src/helpers/transactionFormer.js
@@ -0,0 +1,340 @@
+const sodium = require('sodium-browserify-tweetnacl');
+const crypto = require('crypto');
+const ByteBuffer = require('bytebuffer');
+
+const BigNum = require('./bignumber.js');
+const keys = require('./keys.js');
+const constants = require('./constants.js');
+const time = require('./time.js');
+
+module.exports = {
+  createTransaction(type, data) {
+    const {
+      SEND,
+      VOTE,
+      DELEGATE,
+      CHAT_MESSAGE,
+      STATE,
+    } = constants.transactionTypes;
+
+    const actions = {
+      [SEND]: () => this.createSendTransaction(data),
+      [VOTE]: () => this.createVoteTransaction(data),
+      [DELEGATE]: () => this.createDelegateTransaction(data),
+      [CHAT_MESSAGE]: () => this.createChatTransaction(data),
+      [STATE]: () => this.createStateTransaction(data),
+    };
+
+    const action = actions[type];
+
+    return action ? action() : ({});
+  },
+  createBasicTransaction(data) {
+    const transaction = {
+      type: data.transactionType,
+      timestamp: time.getTime(),
+      amount: 0,
+      senderPublicKey: data.keyPair.publicKey.toString('hex'),
+      senderId: keys.createAddressFromPublicKey(data.keyPair.publicKey),
+      asset: {},
+    };
+
+    return transaction;
+  },
+  createSendTransaction(data) {
+    const details = {
+      ...data,
+      transactionType: constants.transactionTypes.SEND,
+    };
+
+    const transaction = {
+      ...this.createBasicTransaction(details),
+      recipientId: details.recipientId,
+      amount: details.amount,
+      asset: {},
+    };
+
+    transaction.signature = this.transactionSign(transaction, details.keyPair);
+
+    return transaction;
+  },
+  createStateTransaction(data) {
+    const details = {
+      ...data,
+      transactionType: constants.transactionTypes.STATE,
+    };
+
+    const transaction = {
+      ...this.createBasicTransaction(details),
+      recipientId: null,
+      asset: {
+        state: {
+          key: details.key,
+          value: details.value,
+          type: 0,
+        },
+      },
+    };
+
+    transaction.signature = this.transactionSign(transaction, details.keyPair);
+
+    return transaction;
+  },
+  createChatTransaction(data) {
+    const details = {
+      ...data,
+      transactionType: constants.transactionTypes.CHAT_MESSAGE,
+    };
+
+    const transaction = {
+      ...this.createBasicTransaction(details),
+      recipientId: details.recipientId,
+      amount: details.amount || 0,
+      asset: {
+        chat: {
+          message: data.message,
+          own_message: data.own_message,
+          type: data.message_type,
+        },
+      },
+    };
+
+    transaction.signature = this.transactionSign(transaction, details.keyPair);
+
+    return transaction;
+  },
+  createDelegateTransaction(data) {
+    const details = {
+      ...data,
+      transactionType: constants.transactionTypes.DELEGATE,
+    };
+
+    const transaction = {
+      ...this.createBasicTransaction(details),
+      recipientId: null,
+      asset: {
+        delegate: {
+          username: details.username,
+          publicKey: details.keyPair.publicKey.toString('hex'),
+        },
+      },
+    };
+
+    transaction.signature = this.transactionSign(transaction, details.keyPair);
+
+    return transaction;
+  },
+  createVoteTransaction(data) {
+    const details = {
+      ...data,
+      transactionType: constants.transactionTypes.VOTE,
+    };
+
+    const transaction = {
+      ...this.createBasicTransaction(details),
+      asset: {
+        votes: details.votes,
+      },
+    };
+
+    transaction.recipientId = transaction.senderId;
+    transaction.signature = this.transactionSign(transaction, details.keyPair);
+
+    return transaction;
+  },
+  getHash(trs) {
+    const hash = crypto
+        .createHash('sha256')
+        .update(this.getBytes(trs))
+        .digest();
+
+    return hash;
+  },
+  getAssetBytes(transaction) {
+    const {type} = transaction;
+    const {
+      SEND,
+      VOTE,
+      DELEGATE,
+      CHAT_MESSAGE,
+      STATE,
+    } = constants.transactionTypes;
+
+    if (type === SEND) {
+      return {assetBytes: null, assetSize: 0};
+    }
+
+    const actions = {
+      [VOTE]: this.voteGetBytes,
+      [DELEGATE]: this.delegatesGetBytes,
+      [CHAT_MESSAGE]: this.chatGetBytes,
+      [STATE]: this.statesGetBytes,
+    };
+
+    const getBytes = actions[type];
+
+    if (typeof getBytes === 'function') {
+      const assetBytes = getBytes(transaction);
+
+      return {assetBytes, assetSize: assetBytes.length};
+    }
+  },
+  getBytes(transaction) {
+    const skipSignature = false;
+    const skipSecondSignature = true;
+
+    const {assetSize, assetBytes} = this.getAssetBytes(transaction);
+
+    const bb = new ByteBuffer(1 + 4 + 32 + 8 + 8 + 64 + 64 + assetSize, true);
+
+    bb.writeByte(transaction.type);
+    bb.writeInt(transaction.timestamp);
+
+    const senderPublicKeyBuffer = Buffer.from(transaction.senderPublicKey, 'hex');
+
+    for (const buf of senderPublicKeyBuffer) {
+      bb.writeByte(buf);
+    }
+
+    if (transaction.requesterPublicKey) {
+      const requesterPublicKey = Buffer.from(transaction.requesterPublicKey, 'hex');
+
+      for (const buf of requesterPublicKey) {
+        bb.writeByte(buf);
+      }
+    }
+
+    if (transaction.recipientId) {
+      const recipient = new BigNum(
+          transaction.recipientId.slice(1),
+      ).toBuffer({size: 8});
+
+      for (let i = 0; i < 8; i++) {
+        bb.writeByte(recipient[i] || 0);
+      }
+    } else {
+      for (let i = 0; i < 8; i++) {
+        bb.writeByte(0);
+      }
+    }
+
+    bb.writeLong(transaction.amount);
+
+    if (assetSize > 0) {
+      for (const assetByte of assetBytes) {
+        bb.writeByte(assetByte);
+      }
+    }
+
+    if (!skipSignature && transaction.signature) {
+      const signatureBuffer = Buffer.from(transaction.signature, 'hex');
+
+      for (const buf of signatureBuffer) {
+        bb.writeByte(buf);
+      }
+    }
+
+    if (!skipSecondSignature && transaction.signSignature) {
+      const signSignatureBuffer = Buffer.from(transaction.signSignature, 'hex');
+
+      for (const buf of signSignatureBuffer) {
+        bb.writeByte(buf);
+      }
+    }
+
+    bb.flip();
+
+    const arrayBuffer = new Uint8Array(bb.toArrayBuffer());
+    const buffer = [];
+
+    for (let i = 0; i < arrayBuffer.length; i++) {
+      buffer[i] = arrayBuffer[i];
+    }
+
+    return Buffer.from(buffer);
+  },
+  transactionSign(trs, keypair) {
+    const hash = this.getHash(trs);
+
+    return this.sign(hash, keypair).toString('hex');
+  },
+  voteGetBytes(trs) {
+    const {votes} = trs.asset;
+
+    const buf = votes ?
+      Buffer.from(votes.join(''), 'utf8') :
+      null;
+
+    return buf;
+  },
+  delegatesGetBytes(trs) {
+    const {username} = trs.asset.delegate;
+
+    const buf = username ?
+      Buffer.from(username, 'utf8') :
+      null;
+
+    return buf;
+  },
+  statesGetBytes(trs) {
+    const {value} = trs.asset.state;
+
+    if (!value) {
+      return null;
+    }
+
+    let buf = Buffer.from([]);
+
+    const {key, type} = trs.asset.state;
+
+    const stateBuf = Buffer.from(value);
+
+    buf = Buffer.concat([buf, stateBuf]);
+
+    if (key) {
+      const keyBuf = Buffer.from(key);
+      buf = Buffer.concat([buf, keyBuf]);
+    }
+
+    const bb = new ByteBuffer(4 + 4, true);
+
+    bb.writeInt(type);
+    bb.flip();
+
+    buf = Buffer.concat([buf, bb.toBuffer()]);
+
+    return buf;
+  },
+  chatGetBytes(trs) {
+    let buf = Buffer.from([]);
+
+    const {message} = trs.asset.chat;
+    const messageBuf = Buffer.from(message, 'hex');
+
+    buf = Buffer.concat([buf, messageBuf]);
+
+    const {own_message: ownMessage} = trs.asset.chat;
+
+    if (ownMessage) {
+      const ownMessageBuf = Buffer.from(ownMessage, 'hex');
+      buf = Buffer.concat([buf, ownMessageBuf]);
+    }
+
+    const bb = new ByteBuffer(4 + 4, true);
+
+    bb.writeInt(trs.asset.chat.type);
+    bb.flip();
+
+    buf = Buffer.concat([buf, Buffer.from(bb.toBuffer())]);
+
+    return buf;
+  },
+  sign(hash, keypair) {
+    const sign = sodium.crypto_sign_detached(
+        hash,
+        Buffer.from(keypair.privateKey, 'hex'),
+    );
+
+    return sign;
+  },
+};
diff --git a/src/helpers/validator.js b/src/helpers/validator.js
new file mode 100644
index 0000000..179ed6c
--- /dev/null
+++ b/src/helpers/validator.js
@@ -0,0 +1,169 @@
+const constants = require('./constants');
+const bigNumber = require('bignumber.js');
+
+module.exports = {
+  getRandomIntInclusive(minimum, maximum) {
+    const min = Math.ceil(minimum);
+    const max = Math.floor(maximum);
+
+    // The maximum is inclusive and the minimum is inclusive
+    return Math.floor(Math.random() * (max - min + 1) + min);
+  },
+  isNumeric(str) {
+    if (typeof str !== 'string') {
+      return false;
+    }
+
+    return !isNaN(parseFloat(str));
+  },
+  tryParseJSON(jsonString) {
+    try {
+      const o = JSON.parse(jsonString);
+
+      return typeof o === 'object' ? o : false;
+    } catch (e) {
+      return false;
+    }
+  },
+  validatePassPhrase(passPhrase) {
+    return typeof passPhrase === 'string' && passPhrase.length > 30;
+  },
+  validateEndpoint(endpoint) {
+    return typeof endpoint === 'string';
+  },
+  validateAdmAddress(address) {
+    return typeof(address) === 'string' && constants.RE_ADM_ADDRESS.test(address);
+  },
+  validateAdmPublicKey(publicKey) {
+    return (
+      typeof publicKey === 'string' &&
+      publicKey.length === 64 &&
+      constants.RE_HEX.test(publicKey)
+    );
+  },
+  validateAdmVoteForPublicKey(publicKey) {
+    return (
+      typeof publicKey === 'string' &&
+      constants.RE_ADM_VOTE_FOR_PUBLIC_KEY.test(publicKey)
+    );
+  },
+  validateAdmVoteForAddress(address) {
+    return (
+      typeof address === 'string' &&
+      constants.RE_ADM_VOTE_FOR_ADDRESS.test(address)
+    );
+  },
+  validateAdmVoteForDelegateName(delegateName) {
+    return (
+      typeof delegateName === 'string' &&
+      constants.RE_ADM_VOTE_FOR_DELEGATE_NAME.test(delegateName)
+    );
+  },
+  validateIntegerAmount(amount) {
+    return Number.isSafeInteger(amount);
+  },
+  validateStringAmount(amount) {
+    return this.isNumeric(amount);
+  },
+  validateMessageType(messageType) {
+    return [1, 2, 3].includes(messageType);
+  },
+  validateMessage(message, messageType) {
+    if (typeof message !== 'string') {
+      return {
+        result: false,
+        error: `Message must be a string`,
+      };
+    }
+
+    if ([2, 3].includes(messageType)) {
+      const json = this.tryParseJSON(message);
+
+      if (!json) {
+        return {
+          result: false,
+          error: `For rich and signal messages, 'message' must be a JSON string`,
+        };
+      }
+
+      if (json.type && json.type.toLowerCase().includes('_transaction')) {
+        if (json.type.toLowerCase() !== json.type) {
+          return {
+            result: false,
+            error: `Value '<coin>_transaction' must be in lower case`,
+          };
+        }
+      }
+
+      if (typeof json.amount !== 'string' || !this.validateStringAmount(json.amount)) {
+        return {
+          result: false,
+          error: `Field 'amount' must be a string, representing a number`,
+        };
+      }
+    }
+
+    return {
+      result: true,
+    };
+  },
+  validateDelegateName(name) {
+    if (typeof name !== 'string') {
+      return false;
+    }
+
+    return constants.RE_ADM_DELEGATE_NAME.test(name);
+  },
+  admToSats(amount) {
+    return bigNumber(String(amount))
+        .multipliedBy(constants.SAT)
+        .integerValue()
+        .toNumber();
+  },
+  async badParameter(name, value, customMessage) {
+    return {
+      success: false,
+      errorMessage: `Wrong '${name}' parameter${value ? ': ' + value : ''}${customMessage ? '. Error: ' + customMessage : ''}`,
+    };
+  },
+  formatRequestResults(response, isRequestSuccess) {
+    let results = {
+      details: {},
+    };
+
+    if (isRequestSuccess) {
+      results = {
+        success: response.data && response.data.success,
+        data: response.data,
+        details: {
+          status: response.status,
+          statusText: response.statusText,
+          response: response,
+        },
+      };
+
+      if (!results.success && results.data) {
+        results.errorMessage = `Node's reply: ${results.data.error}`;
+      }
+    } else {
+      results = {
+        success: false,
+        data: undefined,
+        details: {
+          status: response.status,
+          statusText: response.response && response.response.statusText,
+          response: response.response && response.response.status,
+          error: response.toString(),
+          message: (
+            response.response &&
+            response.response.data &&
+            response.response.data.toString().trim()
+          ),
+          errorMessage: `${results.details.error}${results.details.message ? '. Message: ' + results.details.message : ''}`,
+        },
+      };
+    }
+
+    return results;
+  },
+};
diff --git a/src/helpers/wsClient.js b/src/helpers/wsClient.js
new file mode 100644
index 0000000..4070521
--- /dev/null
+++ b/src/helpers/wsClient.js
@@ -0,0 +1,91 @@
+const ioClient = require('socket.io-client');
+const logger = require('./logger');
+const validator = require('./validator');
+
+module.exports = {
+  isSocketEnabled: false, // If we need socket connection
+  wsType: 'ws', // Socket connection type, 'ws' (default) or 'wss'
+  admAddress: '', // ADM address to subscribe to notifications
+  connection: null, // Socket connection
+  onNewMessage: null, // Method to process new messages or transactions
+  activeNodes: [], // List of nodes that are active. Not all of them synced and support socket.
+  activeSocketNodes: [], // List of nodes that are active, synced and support socket
+  useFastest: false, // If to connect to node with minimum ping. Not recommended.
+  // Constructor
+  initSocket(params) {
+    this.onNewMessage = params.onNewMessage;
+    this.isSocketEnabled = params.socket;
+    this.wsType = params.wsType;
+    this.admAddress = params.admAddress;
+  },
+  // Runs after every healthCheck() to re-connect socket if needed
+  reviseConnection(nodes) {
+    if (!this.isSocketEnabled) {
+      return;
+    }
+    if (!this.connection || !this.connection.connected) {
+      this.activeNodes = nodes.slice();
+      this.setNodes();
+      this.setConnection();
+    }
+  },
+  // Make socket connection and subscribe to new transactions
+  setConnection() {
+    if (!this.activeSocketNodes.length) {
+      return logger.warn(`[Socket] No supported socket nodes at the moment.`);
+    }
+
+    const node = this.socketAddress();
+    logger.log(`[Socket] Supported nodes: ${this.activeSocketNodes.length}. Connecting to ${node}...`);
+    this.connection = ioClient.connect(node, {reconnection: false, timeout: 5000});
+
+    this.connection.on('connect', () => {
+      this.connection.emit('address', this.admAddress);
+      logger.info('[Socket] Connected to ' + node + ' and subscribed to incoming transactions for ' + this.admAddress + '.');
+    });
+
+    this.connection.on('disconnect', (reason) => {
+      logger.warn('[Socket] Disconnected. Reason: ' + reason);
+    });
+
+    this.connection.on('connect_error', (err) => {
+      logger.warn('[Socket] Connection error: ' + err);
+    });
+
+    this.connection.on('newTrans', (transaction) => {
+      if ((transaction.recipientId === this.admAddress) && (transaction.type === 0 || transaction.type === 8)) {
+        // console.info(`[Socket] New incoming socket transaction received: ${transaction.id}`);
+        this.onNewMessage(transaction);
+      }
+    });
+  },
+  // Save the list of nodes activeSocketNodes that are active, synced and support socket
+  setNodes() {
+    this.activeSocketNodes = this.activeNodes.filter((n) => n.socketSupport & !n.outOfSync);
+    // Remove nodes without IP if 'ws' connection type
+    if (this.wsType === 'ws') {
+      this.activeSocketNodes = this.activeSocketNodes.filter((n) => !n.ifHttps || n.ip);
+    }
+  },
+  // Returns socket url for connection
+  socketAddress() {
+    const node = this.useFastest ? this.fastestNode() : this.randomNode();
+    let socketUrl = this.wsType + '://';
+    if (this.wsType === 'ws') {
+      let host = node.ip;
+      if (!host || host === undefined) {
+        host = node.url;
+      }
+      socketUrl = socketUrl + host + ':' + node.wsPort;
+    } else {
+      socketUrl = socketUrl + node.url; // no port if wss
+    }
+    return socketUrl;
+  },
+  fastestNode() {
+    return this.activeSocketNodes[0]; // They are sorted by ping
+  },
+  randomNode() {
+    return this.activeSocketNodes[validator.getRandomIntInclusive(0, this.activeSocketNodes.length - 1)];
+  },
+};
diff --git a/index.js b/src/index.js
similarity index 59%
rename from index.js
rename to src/index.js
index daba8ec..bdf9495 100644
--- a/index.js
+++ b/src/index.js
@@ -1,45 +1,51 @@
-const constants = require('./helpers/constants.js');
 const get = require('./groups/get');
 const getPublicKey = require('./groups/getPublicKey');
 const decodeMsg = require('./groups/decodeMsg');
+
 const newDelegate = require('./groups/newDelegate');
 const voteForDelegate = require('./groups/voteForDelegate');
 const sendTokens = require('./groups/sendTokens');
 const sendMessage = require('./groups/sendMessage');
 const healthCheck = require('./helpers/healthCheck');
+
 const eth = require('./groups/eth');
 const dash = require('./groups/dash');
 const btc = require('./groups/btc');
 const doge = require('./groups/doge');
 const lsk = require('./groups/lsk');
-const transactionFormer = require('./helpers/transactionFormer');
-const keys = require('./helpers/keys');
+
 const encryptor = require('./helpers/encryptor');
 const socket = require('./helpers/wsClient');
 const logger = require('./helpers/logger');
 
-module.exports = (params, log) => {
-	log = log || console;
-	logger.initLogger(params.logLevel, log);
-	const nodeManager = healthCheck(params.node);
-
-	return {
-		get: get(nodeManager),
-		getPublicKey: getPublicKey(nodeManager),
-		sendTokens: sendTokens(nodeManager),
-		sendMessage: sendMessage(nodeManager),
-		newDelegate: newDelegate(nodeManager),
-		voteForDelegate: voteForDelegate(nodeManager),
-		decodeMsg,
-		eth,
-		dash,
-		btc,
-		doge,
-		lsk,
-		transactionFormer,
-		keys,
-		encryptor,
-		socket,
-		constants
-	};
+const constants = require('./helpers/constants.js');
+const transactionFormer = require('./helpers/transactionFormer');
+const keys = require('./helpers/keys');
+
+module.exports = (params, customLogger) => {
+  const log = customLogger || console;
+
+  logger.initLogger(params.logLevel, log);
+
+  const nodeManager = healthCheck(params.node, params.checkHealthAtStartup);
+
+  return {
+    get: get(nodeManager),
+    getPublicKey: getPublicKey(nodeManager),
+    sendTokens: sendTokens(nodeManager),
+    sendMessage: sendMessage(nodeManager),
+    newDelegate: newDelegate(nodeManager),
+    voteForDelegate: voteForDelegate(nodeManager),
+    decodeMsg,
+    eth,
+    dash,
+    btc,
+    doge,
+    lsk,
+    transactionFormer,
+    keys,
+    encryptor,
+    socket,
+    constants,
+  };
 };