--- id: dev-tools-zilliqajs title: zilliqa-js keywords: - zilliqajs - zilliqa-js - js - installation - apis - examples - zrc2 wallet - hello world - zilliqa description: Zilliqa Websockets --- --- ## Introduction [zilliqa-js](https://github.com/Zilliqa/zilliqa-js) is a Javascript library that allows you to interact with the Zilliqa network nodes - create wallets, deploy contracts, and invoke transitions to interact with smart contracts. ## Source Code The Github repository can be found at [https://github.com/Zilliqa/zilliqa-js](https://github.com/Zilliqa/zilliqa-js) ## Releases All releases of zilliqa-js can be found at [https://www.npmjs.com/package/@zilliqa-js/zilliqa](https://www.npmjs.com/package/@zilliqa-js/zilliqa) Release note can be found at [https://github.com/Zilliqa/zilliqa-js/releases](https://github.com/Zilliqa/zilliqa-js/releases) ## Installation It is recommended that developers install the JavaScript client by making use of the umbrella package `@zilliqa-js/zilliqa`. This takes care of bootstrapping the various modules, which are then accessible as members of the `Zilliqa` class. ```shell yarn add @zilliqa-js/zilliqa # you may also need to install the tslib package. yarn add tslib # bn.js should be added with the above package. if it is not, install it manually. yarn add bn.js ``` ## Methods and APIs The following table provides a description of each module of zilliqa-js and what you may want to use it for. Visit the relevant link of each module to find the detailed description about the methods and apis supported by that module. | package | description | dependencies | | --------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------- | | [`@zilliqa-js/core`](https://github.com/Zilliqa/zilliqa-js/tree/dev-dapps/packages/zilliqa-js-core) | Core abstractions and base classes, such as `HTTPProvider` and network logic for interfacing with the Zilliqa JSON-RPC. | none | | [`@zilliqa-js/account`](https://github.com/Zilliqa/zilliqa-js/tree/dev-dapps/packages/zilliqa-js-account) | `Wallet`, `Account` and `Transaction` abstractions live in this package. | `@zilliqa-js/core`, `@zilliqa-js/crypto`, `@zilliqa-js/util`, `@zilliqa-js/proto` | | [`@zilliqa-js/blockchain`](https://github.com/Zilliqa/zilliqa-js/tree/dev-dapps/packages/zilliqa-js-blockchain) | Main interface to the Zilliqa `JSON-RPC`. | none | | [`@zilliqa-js/contract`](https://github.com/Zilliqa/zilliqa-js/tree/dev-dapps/packages/zilliqa-js-contract) | Exposes a `Contracts` module that takes care of smart contract deployment and interaction. | `@zilliqa-js/account`, `@zilliqa-js/blockchain`, `@zilliqa-js/core`, `@zilliqa-js/util` | | [`@zilliqa-js/crypto`](https://github.com/Zilliqa/zilliqa-js/tree/dev-dapps/packages/zilliqa-js-crypto) | Exposes several loosely-coupled cryptographic convenience functions for working with the Zilliqa blockchain and its cryptographic primitives, such as Schnorr signatures. | `@zilliqa-js/util` | | [`@zilliqa-js/proto`](https://github.com/Zilliqa/zilliqa-js/tree/dev-dapps/packages/zilliqa-js-proto) | Protobuf source files and corresponding generated JS modules. | none | | [`@zilliqa-js/util`](https://github.com/Zilliqa/zilliqa-js/tree/dev-dapps/packages/zilliqa-js-util) | Miscellaneous functions that take care of serialisation/deserialisation and validation. | none | | [`@zilliqa-js/viewblock`](https://github.com/Ashlar/zilliqa-js-viewblock) | Library interfacing with ViewBlock's APIs | `@zilliqa-js/crypto` | ## Demo - ZRC-2 Wallet For this demo, we'll be looking at the zilliqa-js related code of a simple ZRC-2 wallet, [ZRC-2](https://github.com/Zilliqa/ZRC/blob/master/zrcs/zrc-2.md) is a standard for fungible tokens on Zilliqa. The full code can be found at [ZRC-2 Wallet Repository](https://github.com/arnavvohra/dev-portal-examples/tree/master/zrc-2-wallet). This repository is written in React but the zilliqa-js methods & APIs can be used with any javascript framework. ### Details #### Generating Private Key and Address from Encrypted Wallet and a Passphrase ```javascript import { decryptPrivateKey, getAddressFromPrivateKey, } from "@zilliqa-js/crypto"; let keystore = JSON.parse(this.state.encryptedWallet); const pk = await decryptPrivateKey(this.state.passphrase, keystore); const address = getAddressFromPrivateKey(pk); ``` #### Getting User's $ZIL Balance ```javascript const { Zilliqa } = require("@zilliqa-js/zilliqa"); const zilliqa = new Zilliqa("https://dev-api.zilliqa.com"); let balanceState = await zilliqa.blockchain.getBalance(userAddress); if (balanceState) { let balance = balanceState.result.balance; balance = units.fromQa(new BN(balance), units.Units.Zil); // user's $zil balance } ``` #### Getting User's Token Balance ```javascript let userAddress = localStorage.getItem("userAddress"); //userAddress is retrieved from localStorage in this example const { Zilliqa } = require("@zilliqa-js/zilliqa"); const zilliqa = new Zilliqa("https://dev-api.zilliqa.com"); let smartContractState = await zilliqa.blockchain.getSmartContractState( tokenContractAddress ); if (smartContractState) { let balances_map = smartContractState.result.balances_map; userAddress = userAddress.toLowerCase(); let userTokenBalance = balances_map[userAddress]; //user's token balance } ``` #### Sending Tokens to Another Address by Calling 'Transfer' Transition of the ZRC-2 Contract ```javascript sendTransaction = async () => { const { Zilliqa } = require("@zilliqa-js/zilliqa"); const zilliqa = new Zilliqa("https://dev-api.zilliqa.com"); const { BN, Long, bytes, units } = require("@zilliqa-js/util"); const { toBech32Address, fromBech32Address } = require("@zilliqa-js/crypto"); //You can set the value of the following variables according to your liking let contractAddress = localStorage.getItem("token_contract_address"); let recipientAddress = this.state.sendingAddress; let sendingAmount = this.state.sendingAmount; let privkey = localStorage.getItem("private_key"); zilliqa.wallet.addByPrivateKey(privkey); const CHAIN_ID = 333; const MSG_VERSION = 1; const VERSION = bytes.pack(CHAIN_ID, MSG_VERSION); const myGasPrice = units.toQa("2000", units.Units.Li); // Gas Price that will be used by all transactions contractAddress = contractAddress.substring(2); recipientAddress = fromBech32Address(recipientAddress); //converting to ByStr20 format const ftAddr = toBech32Address(contractAddress); try { const contract = zilliqa.contracts.at(ftAddr); const callTx = await contract.call( "Transfer", [ { vname: "to", type: "ByStr20", value: recipientAddress, }, { vname: "amount", type: "Uint128", value: sendingAmount, }, ], { // amount, gasPrice and gasLimit must be explicitly provided version: VERSION, amount: new BN(0), gasPrice: myGasPrice, gasLimit: Long.fromNumber(10000), } ); } catch (err) { console.log(err); } }; ```