Matic SDK

This repository contains the maticjs client lib. maticjs makes it easy for developers, who may not be deeply familiar with smart contract development, to interact with the various components of Matic Network.

This library will help developers to move assets from Ethereum chain to Matic chain, and withdraw from Matic to Ethereum using fraud proofs.

We will be improving this library to make all features available like Plasma Faster Exit, challenge exit, finalize exit and more.

Installation

$ npm install --save maticjs # or yarn add maticjs

Getting started

// Import Matic sdk
import Matic from 'maticjs'

// Create sdk instance
const matic = new Matic({

  // Set Matic provider - string or provider instance
  // Example: 'https://testnet.matic.network' OR new Web3.providers.HttpProvider('http://localhost:8545')
  maticProvider: <web3-provider>,

  // Set Mainchain provider - string or provider instance
  // Example: 'https://kovan.infura.io' OR new Web3.providers.HttpProvider('http://localhost:8545')
  parentProvider: <web3-provider>,

  // Set rootchain contract. See below for more information
  rootChainAddress: <root-contract-address>,

  // Set matic network's WETH address. See below for more information
  maticWethAddress: <matic-weth-address>,

  // Syncer API URL
  // Fetches tx/receipt proof data instead of fetching whole block on client side
  syncerUrl: 'https://eth-syncer.api.matic.network/api/v1', // (optional)

  // Watcher API URL
  // Fetches headerBlock info from mainchain & finds appropriate headerBlock for given blockNumber
  watcherUrl: 'https://eth-watcher.api.matic.network/api/v1', // (optional)
})

// Set wallet
// Warning: Not-safe
// matic.wallet = <private-key> // Use metamask provider or use WalletConnect provider instead.

// get token address mapped with mainchain token address
const tokenAddressOnMatic = await matic.getMappedTokenAddress(
  tokenAddress // token address on mainchain
)

// Approve token for deposit
await matic.approveTokensForDeposit(
  token,  // Token address,
  amount,  // Token amount for approval (in wei)
  options // transaction fields
)

// Deposit token into Matic chain. Remember to call `approveTokens` before
await matic.depositTokens(
  token,  // Token address
  user,   // User address (in most cases, this will be sender's address),
  amount,  // Token amount for deposit (in wei)
  options // transaction fields
)

// Transfer Ethers on Matic
await matic.transferMaticEthers(
  user,   // Recipient address
  amount,  // Token amount for deposit (in wei)
  options // transaction fields
)

// Transfer token on Matic
await matic.transferTokens(
  token,  // Token address
  user,   // Recipient address
  amount,  // Token amount for deposit (in wei)
  options // transaction fields
)

// Initiate withdrawal of funds from Matic and retrieve the Transaction id
await matic.startWithdraw(
  token, // Token address
  amount, // Token amount for withdraw (in wei)
  options // transaction fields
)

// Withdraw funds from the Matic chain using the Transaction id generated from the 'startWithdraw' method
// after header has been submitted to mainchain
await matic.withdraw(
  txId, // Transaction id generated from the 'startWithdraw' method
  options // transaction fields
)

How it works?

The flow for asset transfers on the Matic Network is as follows:

• User deposits crypto assets in Matic contract on mainchain
• Once deposited tokens get confirmed on the main chain, the corresponding tokens will get reflected on the Matic chain.
• The user can now transfer tokens to anyone they want instantly with negligible fees. Matic chain has faster blocks (approximately ~ 1 second). That way, the transfer will be done almost instantly.
• Once a user is ready, they can withdraw remaining tokens from the mainchain by establishing proof of remaining tokens on Root contract (contract deployed on Ethereum chain)

Contracts and addresses

Matic Testnet

• RPC endpoint host: https://testnet.matic.network
• TEST childchain ERC20 token: 0x343461c74133E3fA476Dbbc614a87473270a226c

Kovan testnet addresses

• TEST mainchain ERC20 token: 0x670568761764f53E6C10cd63b71024c31551c9EC
• Root Contract: 0x24e01716a6ac34D5f2C4C082F553D86a557543a7

Faucet

Please write to [email protected] to request TEST tokens for development purposes. We will soon have a faucet in place for automatic distribution of tokens for testing.

API

• new Matic()
• matic.getMappedTokenAddress()
• matic.approveTokensForDeposit()
• matic.depositTokens()
• matic.depositEthers()
• matic.transferMaticEthers()
• matic.transferTokens()
• matic.transferEthers()
• matic.startWithdraw()
• matic.getHeaderObject()
• matic.withdraw()
• matic.getTx()
• matic.getReceipt()

---

new Matic(options)

Creates Matic SDK instance with give options. It returns a MaticSDK object.

import Matic from "maticjs"

const matic = new Matic(options)

• options is simple Javascript object which can have following fields:
  • maticProvider can be string or Web3.providers instance. This provider must connect to Matic chain. Value can be anyone of following:
    • 'https://testnet.matic.network'
    • new Web3.providers.HttpProvider('http://localhost:8545')
    • WalletConnect Provider instance
  • parentProvider can be string or Web3.providers instance. This provider must connect to Ethereum chain (testnet or mainchain). Value can be anyone of following:
    • 'https://kovan.infura.io'
    • new Web3.providers.HttpProvider('http://localhost:8545')
    • WalletConnect Provider instance
  • rootChainAddress must be valid Ethereum contract address.
  • syncerUrl must be valid API host. MaticSDK uses this value to fetch receipt/tx proofs instead of getting whole block to client side.
  • watcherUrl must be valid API host. MaticSDK uses this value to fetch headerBlock info from mainchain and to find appropriate headerBlock for given blockNumber.

---

matic.getMappedTokenAddress(tokenAddress)

get matic token address mapped with mainchain tokenAddress.

• tokenAddress must be valid token address

This returns matic address.

Example:

matic
  .getMappedTokenAddress("0x670568761764f53E6C10cd63b71024c31551c9EC")
  .then(address => {
    console.log("matic address", address)
  })

---

matic.approveTokensForDeposit(token, amount, options)

Approves given amount of token to rootChainContract.

• token must be valid ERC20 token address
• amount must be token amount in wei (string, not in Number)
• options (optional) must be valid javascript object containing from, gasPrice, gasLimit, nonce, value, onTransactionHash, onReceipt or onError
  • from must be valid account address
  • gasPrice same as Ethereum sendTransaction
  • gasLimit same as Ethereum sendTransaction
  • nonce same as Ethereum sendTransaction
  • nonce same as Ethereum sendTransaction
  • value contains ETH value. Same as Ethereum sendTransaction.
  • onTransactionHash must be function. This function will be called when transaction will be broadcasted.
  • onReceipt must be function. This function will be called when transaction will be included in block (when transaction gets confirmed)
  • onError must be function. This function will be called when sending transaction fails.

This returns Promise object, which will be fulfilled when transaction gets confirmed (when receipt is generated).

Example:

matic
  .approveTokensForDeposit("0x718Ca123...", "1000000000000000000", {
    from: "0xABc578455..."
  })
  .on("onTransactionHash", txHash => {
    console.log("New transaction", txHash)
  })

---

matic.depositTokens(token, user, amount, options)

Deposit given amount of token with user user.

• token must be valid ERC20 token address
• user must be value account address
• amount must be token amount in wei (string, not in Number)
• options see more infomation here

This returns Promise object, which will be fulfilled when transaction gets confirmed (when receipt is generated).

Example:

const user = <your-address> or <any-account-address>

matic.depositToken('0x718Ca123...', user, '1000000000000000000', {
  from: '0xABc578455...'
})

---

matic.depositEthers(user, options)

Deposit options.value ETH with user user.

• user must be value account address
• options see more infomation here. Pass value for amount of ethers.

This returns Promise object, which will be fulfilled when transaction gets confirmed (when receipt is generated).

Example:

const user = <your-address> or <any-account-address>

matic.depositEthers('0x718Ca123...', {
  from: '0xABc578455...',
  value: '1000000000000000000'
})

---

matic.transferMaticEthers(user, amount, options)

Transfer given amount of Ethers to user.

• user must be value account address
• amount must be token amount in wei (string, not in Number)
• options see more infomation here

This returns Promise object, which will be fulfilled when transaction gets confirmed (when receipt is generated).

Example:

const user = <your-address> or <any-account-address>

matic.transferMaticEthers(user, '1000000000000000000', {
  from: '0xABc578455...',
})

---

matic.transferTokens(token, user, amount, options)

Transfer given amount of token to user.

• token must be valid ERC20 token address
• user must be value account address
• amount must be token amount in wei (string, not in Number)
• options see more infomation here
  • parent must be boolean value. For token transfer on Main chain, use parent: true

This returns Promise object, which will be fulfilled when transaction gets confirmed (when receipt is generated).

Example:

const user = <your-address> or <any-account-address>

matic.transferTokens('0x718Ca123...', user, '1000000000000000000', {
  from: '0xABc578455...',

  // For token transfer on Main network
  // parent: true
})

---

matic.transferEthers(user, amount, options)

Transfer given amount of ethers to user.

• user must be value account address
• amount must be ethers amount in wei (string, not in Number)
• options see more infomation here
  • parent must be boolean value. For ether transfer on Main chain, use parent: true

This returns Promise object, which will be fulfilled when transaction gets confirmed (when receipt is generated).

Example:

const user = <your-address> or <any-account-address>

matic.transferEthers(user, '1000000000000000000', {
  from: '0xABc578455...',

  // For token transfer on Main network
  // parent: true
})

---

matic.startWithdraw(token, amount, options)

Start withdraw process with given amount for token.

• token must be valid ERC20 token address
• amount must be token amount in wei (string, not in Number)
• options see more infomation here

This returns Promise object, which will be fulfilled when transaction gets confirmed (when receipt is generated).

Example:

matic
  .startWithdraw("0x718Ca123...", "1000000000000000000", {
    from: "0xABc578455..."
  })
  .on("onTransactionHash", txHash => {
    console.log("Started withdraw process with txId", txHash)
  })

---

matic.getHeaderObject(blockNumber)

Fetch header/checkpoint corresponding to blockNumber

• blockNumber must be valid Matic's sidechain block number

This returns Promise object, which will be fulfilled when header/checkpoint is found corresponding to blockNumber.

Example:

matic.getHeaderObject(673874).then(header => {
  // header.start
  // header.end
  // header.proposer
  // header.number
})

---

matic.withdraw(txId, options)

Withdraw tokens on mainchain using txId from startWithdraw method after header has been submitted to mainchain.

• txId must be valid tx hash
• options see more infomation here

This returns Promise object, which will be fulfilled when transaction gets confirmed (when receipt is generated).

Example:

matic.withdraw("0xabcd...789", {
  from: "0xABc578455..."
})

---

matic.getTx(txId)

Get transaction object using txId from Matic chain.

• txId must be valid tx id

This returns Promise object.

Example:

matic
  .getTx("0x9fc76417374aa880d4449a1f7f31ec597f00b1f6f3dd2d66f4c9c6c445836d8b")
  .then(txObject => {
    console.log(txObject)
  })

---

matic.getReceipt(txId)

Get receipt object using txId from Matic chain.

• txId must be valid tx id

This returns Promise object.

Example:

matic
  .getReceipt(
    "0x9fc76417374aa880d4449a1f7f31ec597f00b1f6f3dd2d66f4c9c6c445836d8b"
  )
  .then(obj => {
    console.log(obj)
  })

Support

Please write to [email protected] for integration support. If you have any queries, feedback or feature requests, feel free to reach out to us on telegram: t.me/maticnetwork

License

MIT