1.6.11 • Public • Published


NEM Developer Kit for Node.js and the browser


  • Easy integration
  • Organised in namespaces
  • Create wallets compatible with Nano Wallet client
  • Simple transactions
  • Mosaic transactions
  • Encrypted, unencrypted and hex messaging
  • Create and audit Apostilles
  • Create and verify signatures
  • Helpers and formatting functions
  • 22 NIS API requests with promises
  • Websockets for real time blockchain data
  • Commented code and examples
  • Browser examples ready to use out of the box


Table of Contents

  1. Introduction
  1. Objects
  1. Transactions
  1. Communications
  1. Helpers and Format
  1. Private Keys
  1. Addresses
  1. Crypto Helpers
  2. Wallets
  1. Apostille

1 - Introduction

1.1 - Installation

For the browser:

Download the library source, open the dist/ folder and put nem-sdk.js into your project.

Library include the require() function so you can require() the module directly

<script src="nem-sdk.js"></script>
  // Include the library
  var nem = require("nem-sdk").default;

For Node:

Using npm:

npm install nem-sdk

// Use require
var nem = require("nem-sdk").default;
// ES6
import nem from 'nem-sdk';
Using build/ folder:
// Use the build/ folder
var nem = require("path/to/build/index.js").default;

1.2 - Build

Install dependencies:

npm install


npm run build

Build for the browser (after above build):

npm run browserify

1.3 - Organisation

The SDK is organised in namespaces and sub-namespaces.

There is 4 main namespaces:

  • requests: Requests to NIS and the outside world
  • websockets: Connection, subscription and requests to NIS websockets


  • keyPair: Functions to create keypair from hex and sign data with it
  • helpers: Miscellaneous cryptographic functions, like encrypt private key, decrypt a wallet, derive a password...
  • nacl: External cryptographic library modified for NEM
  • js: Access to the crypto-js library


  • address: Functions regarding NEM addresses like base32 encoding / decoding, verify, convert public key to address...
  • objects: Contains usesul objects models
  • fees: Contains all the transaction fees and calculation functions
  • network: Contains networks types and functions related
  • nodes: Contains array of nodes for different networks, default nodes, search by hash nodes...
  • sinks: Contains the sink addresses for namespaces and mosaics by network
  • transactions: Contains functions to prepare and send transaction objects
  • transactionTypes: Contains all the NEM transactions types
  • wallet: Contains functions to create wallets


  • convert: Contains convertion functions
  • helpers: Contains miscellaneous helper functions
  • format: Contains miscellaneous formatting functions
  • nty: Contains functions to build nty data
  • Serialization: Contains functions to serialize transactions

Consult the code directly for details, almost all functions are commented, with parameters, return values and types.

2 - Objects

Namespace: nem.model.objects

This namespace allow to easily get or create objects to use in the SDK. Each object is accessible via a keyword.

Public methods:

  • get
  • create


  • common: An object to hold password and private key
  • endpoint: An object containing info about a remote node
  • mosaicAttachment: An object containing mosaic data to join in a transfer transaction
  • mosaicDefinitionMetaDataPair: An object of objects containing mosaics properties
  • invoice: An invoice object working on NEM mobile clients
  • transferTransaction: An un-prepared transfer transaction object
  • signatureTransaction: An un-prepared signature transaction object

2.1 - Get objects

Return an empty object


// Get an empty object
var object = nem.model.objects.get("keyword");


// Get an empty object
var transferTransaction = nem.model.objects.get("transferTransaction");


    "amount": "",
    "recipient": "",
    "recipientPublicKey": "",
    "isMultisig": false,
    "multisigAccount" : "",
    "message": "",
    "isEncrypted" : false,
    "mosaics": []

2.2 - Create objects

Return an object with parameters.

Using the create method takes different parameters depending of the object.


Name Type Description
password string A password
privateKey string A private key
Name Type Description
host string An NIS uri
port string An NIS port
Name Type Description
namespaceId string A namespace name
mosaicName string A mosaic name
quantity long number A quantity in micro-units
Name Type Description
recipient string A recipient address
amount number An amount
message string A message to join


// Create an object with parameters
var object = nem.model.objects.create("keyword")(param1, param2, ...);


// Create an object with parameters
var transferTransaction = nem.model.objects.create("transferTransaction")("TBCI2A67UQZAKCR6NS4JWAEICEIGEIM72G3MVW5S", 10, "Hello");


    "amount": 10,
    "recipientPublicKey": "",
    "isMultisig": false,
    "multisigAccount" : "",
    "message": "Hello",
    "isEncrypted" : false,
    "mosaics": []

2.3 - More

Consult src/model/objects.js for details about objects and creation parameters

3 - Transactions

Namespace: nem.model.transactions

Public methods:

  • prepare
  • send
  • prepareMessage


  • transferTransaction
  • mosaicTransferTransaction
  • signatureTransaction

This namespace is used to prepare and send transactions.

For now only preparation of simple and mosaics transactions with encrypted, unencrypted and hex messages are implemented.

3.1 - Create and prepare transaction objects

In part 2 you can see in the examples how to build a transfer transaction object, with or without data.

Transaction objects you will create via nem.model.objects are un-prepared transaction objects. They only contain raw / incomplete data and need to be arranged before being signed and sent.

Using the prepare method takes different parameters depending of the transaction object.


Name Type Description
common object A common object
tx object A transferTransaction object
network number A network id
Name Type Description
common object A common object
tx object A transferTransaction object
mosaicDefinitionMetaDataPair object A mosaicDefinitionMetaDataPair object (see 3.4)
network number A network id


// Prepare a transaction object
var preparedTransaction = nem.model.transactions.prepare("keyword")(param1, param2, ...);

Transfer transaction example:

// Create an object with parameters
var transferTransaction = nem.model.objects.create("transferTransaction")("TBCI2A67UQZAKCR6NS4JWAEICEIGEIM72G3MVW5S", 10, "Hello");

// Prepare the above object
var transactionEntity = nem.model.transactions.prepare("transferTransaction")(common, transferTransaction,


	type: 257,
  	version: -1744830463,
  	signer: '0257b05f601ff829fdff84956fb5e3c65470a62375a1cc285779edd5ca3b42f6',
  	timeStamp: 62995509,
  	deadline: 62999109,
  	amount: 10000000,
  	fee: 2000000,
  	message: { type: 1, payload: '48656c6c6f' },
  	mosaics: null

You can easily see the difference between an un-prepared transaction object (2.2) and above prepared object.


Amounts are in the smallest unit possible in a prepared transaction object:

1000000 = 1 XEM

Signature transaction example:

// Create an object with parameters (multisig account address and inner transaction hash)
var signatureTransaction = nem.model.objects.create("signatureTransaction")("TBCI2A67UQZAKCR6NS4JWAEICEIGEIM72G3MVW5S", "161d7f74ab9d332acd46f96650e74371d65b6e1a0f47b076bdd7ccea37903175");

// Prepare the above object
var transactionEntity = nem.model.transactions.prepare("signatureTransaction")(common, signatureTransaction,


  type: 4098,
  version: -1744830463,
  signer: '0257b05f601ff829fdff84956fb5e3c65470a62375a1cc285779edd5ca3b42f6',
  timeStamp: 62995509,
  deadline: 62999109,
  otherHash: {
    data: '161d7f74ab9d332acd46f96650e74371d65b6e1a0f47b076bdd7ccea37903175'
  fee: 6000000

3.2 - Sending prepared transactions

Once your transaction is prepared simply use the send method of the namespace.


Name Type Description
common object A common object
entity object A prepared transaction object
endpoint object An endpoint object


// Serialize transfer transaction and announce
nem.model.transactions.send(common, transactionEntity, endpoint).then(function(res) {....});


A NemAnnounceResult object (

3.3 - Transfer transactions without mosaics

The two provided example speaks for themselves:

  • See examples/node/transfer.js for node
  • See examples/browser/transfer for browser

The node version contains only the strict necessary while browser example needs to handle form and update fees.

3.4 - Transfer transactions with mosaics

  • See examples/node/mosaicTransfer.js for node
  • See examples/browser/mosaicTransfer for browser

Similar to transfer transaction, it use the same un-prepared transferTransaction object, but needs an array of mosaicAttachment objects.

Keyword of the preparation function is mosaicTransferTransaction.

Preparation of mosaic transfer transactions requires a mosaicDefinitionMetaDataPair object containing mosaic definitions of the mosaics you are joining to the transaction.

Definitions are needed to know informations about the included mosaic(s) and calculate quantity and fee accordingly.

Two ways are possible to get mosaic definitions:

  1. You can take it from NIS API using and put the definition into model/objects.js, in the mosaicDefinitionMetaDataPair object (like shown by the comments). If mosaics used in your application are fixed, it is the way to go.

  2. Query the network using the embedded API requests ( as shown in the examples. If mosaics used in your application are not fixed, it is the way to go.

4 - Communications

4.1 - Create endpoints

To communicate with an NIS you need an endpoint object. The object contains the node host and port so it is easier to handle.


// Custom endpoint
var endpoint = nem.model.objects.create("endpoint")("http://myNode", 7890);

// Using sdk data
var endpoint = nem.model.objects.create("endpoint")(nem.model.nodes.defaultTestnet, nem.model.nodes.defaultPort);

4.2 - API requests


22 NIS API calls and a few other external requests are implemented and organised in namespaces:

  • data: Gets account data
  • forwarded: Gets the account data of the account for which the given account is the delegate account
  • harvesting.blocks: Gets harvested blocks
  • harvesting.stop: Stop delegated harvesting
  • harvesting.start: Start delegated harvesting
  • namespaces.owned: Gets namespaces that an account owns
  • mosaics.owned: Gets mosaics that an account owns
  • mosaics.allDefinitions: Gets all mosaic definitions that an account owns
  • mosaics.definitions: Gets mosaic definitions that an account has created
  • transactions.incoming: Gets incoming transactions
  • transactions.unconfirmed: Gets unconfirmed transactions
  • transactions.all: Gets all transactions
  • transactions.outgoing: Gets outgoing transactions
  • unlockInfo: Gets information about the maximum number of allowed harvesters and how many harvesters are already using the node

  • audit: Audit an apostille

  • height: Gets the chain height
  • lastBlock: Gets the last block
  • time: Get network time

  • heartbeat: Gets the node status

  • xem: Gets XEM price in BTC
  • btc: Gets BTC price in $

  • roots: Gets root namespaces
  • info: Gets the namespace with given id
  • mosaicDefinitions: Gets mosaic definitions of a namespace

  • all: Gets all supernodes info

  • byHash: Gets a transaction by hash
  • announce: Announce a transaction to the network

4.3 - Usage

Requests are wrapped in Promises which allow to use then() for callbacks


// Gets chain height {
}, function(err) {

// Gets account data, "TBCI2A67UQZAKCR6NS4JWAEICEIGEIM72G3MVW5S").then(...);

4.4 - More

Consult src/com/requests for details about requests parameters.

  • See examples/browser/monitor for browser demonstration
  • See examples/node/requests for all requests in node

4.5 - WebSockets


Note: For now webSockets use two versions of SockJS to work in Node (v1.1.4) and the browser (v0.3.4). Using only latest SockJS v1.1.4, gives an error when used in browser:

XMLHttpRequest cannot load A wildcard '*' cannot be used in the 'Access-Control-Allow-Origin' header when the credentials flag is true. Origin 'null' is therefore not allowed access.

If anyone has a solution to that, it is welcome.

  • create: Create a connector object
  • close: Close the websocket connection

  • errors: Subscribes to error channel

  • data: Subscribes to account data channel
  • transactions.recent: Subscribes to recent transactions channel
  • transactions.confirmed: Subscribes to confirmed transactions channel
  • transactions.unconfirmed: Subscribes to unconfirmed transactions channel

  • height: Subscribes to new chain height channel
  • blocks: Subscribes to new blocks channel

  • data: Requests account data from channel
  • transactions.recent: Requests recent transactions from channel

4.6 - Usage

You first need to create a connector object pointing to the right endpoint then use this connector to open the connection.

If connection is a success, the connector.connect function will resolve a promise in a .then() function, in which you can request and subscribe to channels.

Subscription takes a connector and resolve in a simple callback function (.then() not supported), where your data will be received from the channel. It acts exactly like a .on('something').


Name Type Description
endpoint object An endpoint object (using websocket port)
address string A NEM account address
All subscription methods
Name Type Description
connector object An open connector object
callback function A callback function where data will be received
address string A NEM account address (optional, for custom account subscription)
All request methods
Name Type Description
connector object An open connector object
address string A NEM account address (optional, for custom account request)


// Create an endpoint object
var endpoint = nem.model.objects.create("endpoint")(nem.model.nodes.defaultTestnet, nem.model.nodes.websocketPort);

// Address to subscribe

// Create a connector object
var connector =, address);

// Connect using connector
connector.connect().then(function() {
  // If we are here we are connected

  // Subscribe to new blocks channel, function(res) {

  // Subscribe to account data channel, function(res) {

  // Request account data;

}, function (err) {
  // If we are here connection failed 10 times (1/s).

4.7 - More

Consult src/com/websockets for details.

  • See examples/browser/websockets for browser demonstration
  • See examples/nodejs/websockets.js for Node demonstration

5 - Helpers and Format

5.1 - Helpers

Namespace: nem.utils.helpers

Public methods:

  • needsSignature
  • haveTx
  • getTransactionIndex
  • haveCosig
  • createNEMTimeStamp
  • fixPrivateKey
  • isPrivateKeyValid
  • isPublicKeyValid
  • checkAndFormatUrl
  • createTimeStamp
  • getTimestampShort
  • convertDateToString
  • extendObj
  • isHexadecimal
  • searchMosaicDefinitionArray
  • grep
  • isTextAmountValid
  • cleanTextAmount
  • formatEndpoint

5.2 - Format

Namespace: nem.utils.format

Public methods:

  • address
  • hexMessage
  • hexToUtf8
  • importanceTransferMode
  • levyFee
  • nemDate
  • nemImportanceScore
  • nemValue
  • pubToAddress
  • splitHex
  • supply
  • supplyRaw
  • mosaicIdToName
  • txTypeToName

Format address

Add hyphens to unformatted address.


Name Type Description
address string An unformatted NEM address



// Add hyphens to NEM address
var fmtAddress = nem.utils.format.address(address); //TBCI2A-67UQZA-KCR6NS-4JWAEI-CEIGEI-M72G3M-VW5S

Format a nem quantity

Change a NEM quantity into an array of values.

Quantity means the smallest unit (1.000000 XEM = 1'000'000)


Name Type Description
data number A quantity (smallest unit)


var xemQuantity = 10003002; // Smallest unit for XEM

// Format quantity
var fmt = nem.utils.format.nemValue(xemQuantity)

var fmtAmount = fmt[0] + "." + fmt[1]; // 10.003002

Format a message object

Format hexadecimal payload contained in message objects.

Message objects also contains type:

Type 1: Plain message. Type 2: Encrypted message.


Name Type Description
msg object A message object


var msg = {
  "type": 1,
  "payload": "4e454d20697320617765736f6d652021"

// Format msg
var fmt = nem.utils.format.hexMessage(msg); // NEM is awesome !

6 - Private Keys

A private key is a 64 or 66 characters hex string, looking like this:

// 64 characters hexadecimal private key

// 66 characters hexadecimal private key (always start with 00 in that case)

6.1 - Create private keys

To obtain a private key, 4 choices are possible:

  1. You can type yourself a random 64 hexadecimal string

  2. Use the included PRNG:

// Create random bytes from PRNG
var rBytes = nem.crypto.nacl.randomBytes(32);

// Convert the random bytes to hex
var privateKey = nem.utils.convert.ua2hex(rBytes);
  1. Create a private key from a passphrase:
// Derive a passphrase to get a private key
var privateKey = nem.crypto.helpers.derivePassSha(passphrase, 6000).priv;
  1. Use a private key from another source.

6.2 - Create key pairs

Key pairs are objects representing accounts keys (private, secret and public) and are used to sign data or transactions.


Name Type Description
hexData string 64 or 66 hexadecimal characters


// A funny but valid private key
var privateKey = "aaaaaaaaaaeeeeeeeeeebbbbbbbbbb5555555555dddddddddd1111111111aaee";

// Create a key pair
var keyPair = nem.crypto.keyPair.create(privateKey);

6.3 - Sign with key pair

To sign a transaction or any other data simply use the above keyPair object


var signature = keyPair.sign(data);

6.4 - Extract public key from key pair

You can extract the public key from the keyPair object very easily


var publicKey = keyPair.publicKey.toString();

6.5 - Verify a signature

To verify a signature you need the signer public key, the data that have been signed and the signature.


Name Type Description
publicKey string The signer public key
data string The data that were signed
signature string The signature of the data


var signer = "0257b05f601ff829fdff84956fb5e3c65470a62375a1cc285779edd5ca3b42f6"
var signature = "392511e5b1d78e0991d4cb2a10037cc8be775e56d76b8157a4da726ccb44042e9b419084c09128ffe2a78fe78e2a19beb0e2f57e14b66c962187e61457bd9e09"
var data = "NEM is awesome !";
// Verify
var result = nem.crypto.verifySignature(signer, data, signature);
  • See examples/nodejs/verifySignature.js for node demonstration

7 - Addresses

Namespace: nem.model.address

Public methods:

  • b32encode
  • b32decode
  • toAddress
  • isFromNetwork
  • isValid
  • clean

Addresses are base32 string used to receive XEM. They look like this:


The version without hyphens ("-") is the one we'll use in our queries and lower level processing. The formatted version is only for visual purposes.

Beginning of the address depend of the network:

  • Mainnet (104): N

  • Testnet (-104): T

  • Mijin (96): M

7.1 - Convert public key to an address

var address = nem.model.address.toAddress(publicKey, networkId)

7.2 - Verify address validity

var isValid = nem.model.address.isValid(address);

7.3 - Verify if address is from given network

var isFromNetwork = nem.model.address.isFromNetwork(address, networkId);

7.4 - More

Consult src/model/address.js for more details

8 - Crypto Helpers

Namespace: nem.crypto.helpers

Public methods:

  • toMobileKey
  • derivePassSha
  • passwordToPrivatekey
  • checkAddress
  • randomKey
  • decrypt
  • encrypt
  • encodePrivKey
  • encode
  • decode

9 - Wallets

Namespace: nem.model.wallet

Public methods:

  • createPRNG
  • createBrain
  • importPrivateKey

The SDK allow to create wallets 100% compatible with the Nano Wallet client (as BIP32 not implemented yet the client will ask for an upgrade).

Wallet can contain multiple accounts in an object of objects. The first account is the primary account and is labelled like this by default.

Every accounts objects but primary of brain wallets contains an encrypted private key. Brain wallets primary do not contains an encrypted private key because it is retrieved by the password / passphrase.

Each wallet has an algo property, it is needed to know how to decrypt the accounts.

Wallet files (.wlt) are just storing a wallet object as base 64 strings.

9.1 - Create simple wallets

nem.model.wallet.createPRNG create a wallet object with the primary account's private key generated from a PRNG

// Set a wallet name
var walletName = "QuantumMechanicsPRNG";

// Set a password
var password = "Something";

// Create PRNG wallet
var wallet = nem.model.wallet.createPRNG(walletName, password,;

9.2 - Create brain wallets

nem.model.wallet.createBrain create a wallet object with primary account's private key derived from a password/passphrase

// Set a wallet name
var walletName = "QuantumMechanicsBrain";

// Set a password/passphrase
var password = "Something another thing and something else";

// Create Brain wallet
var wallet = nem.model.wallet.createBrain(walletName, password,;

9.3 - Create private key wallets

nem.model.wallet.importPrivateKey create a wallet object with primary account's private key imported

// Set a wallet name
var walletName = "QuantumMechanicsImported";

// Set a password
var password = "Something";

// Set private key
var privateKey = "Private key to import";

// Create a private key wallet
var wallet = nem.model.wallet.importPrivateKey(walletName, password, privateKey,;

9.4 - Create wallet files

Create an empty file, name it walletName.wlt and put the base 64 string given by below code

// Convert stringified wallet object to word array
var wordArray = nem.crypto.js.enc.Utf8.parse(JSON.stringify(wallet));

// Word array to base64
var base64 = nem.crypto.js.enc.Base64.stringify(wordArray);

9.5 - Decrypt account in wallet

nem.crypto.helpers.passwordToPrivatekey is a function to decrypt an account into a wallet and return it's private key into the common object

// Create a common object
var common = nem.model.objects.create("common")("walletPassword/passphrase", "");

// Get the wallet account to decrypt
var walletAccount = wallet.accounts[index];

// Decrypt account private key 
nem.crypto.helpers.passwordToPrivatekey(common, walletAccount, wallet.algo);

// The common object now has a private key

10 - Apostille

Namespace: nem.model.apostille

Public methods:

  • create
  • generateAccount
  • hashing
  • verify

This namespace is used to create and verify Apostilles. For detailled informations about Apostille:

10.1 - Create an Apostille

nem.model.apostille.create create an apostille object containing information about the apostille, and the transaction ready to be sent via nem.model.transactions.send.


// Create a common object holding key
var common = nem.model.objects.create("common")("", "privateKey");

// Simulate the file content
var fileContent = nem.crypto.js.enc.Utf8.parse('Apostille is awesome !');

// Create the Apostille
var apostille = nem.model.apostille.create(common, "Test.txt", fileContent, "Test Apostille", nem.model.apostille.hashing["SHA256"], false, {}, true,;

// Serialize transfer transaction and announce
nem.model.transactions.send(common, apostille.transaction, endpoint).then(...)
  • See examples/node/apostille/create for creation example in node

10.2 - Verify an Apostille

nem.model.apostille.verify verify an apostille from a file content (as Word Array) and an apostille transaction object.

// Create an NIS endpoint object
var endpoint = nem.model.objects.create("endpoint")(nem.model.nodes.defaultTestnet, nem.model.nodes.defaultPort);

// Simulate the file content
var fileContent = nem.crypto.js.enc.Utf8.parse('Apostille is awesome !');

// Transaction hash of the Apostille
var txHash = "9b2dc096fb55e610c97a870b1d385458ca3d60b6f656428a981069ab8edd9a28";

// Get the Apostille transaction from the chain, txHash).then(function(res) {
  // Verify
  if (nem.model.apostille.verify(fileContent, res.transaction)) {
    console.log("Apostille is valid");
  } else {
    console.log("Apostille is invalid");
}, function(err) {
  console.log("Apostille is invalid");
  • See examples/node/apostille/audit for verification example in node

10.3 - More

Consult src/model/apostille.js for more details




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