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Getting Started

This page will help you understand the basics of how Matic Network works.

To deploy contracts on the Matic, you can read our tutorial on How to deploy contracts on Matic Testnet

It is recommended that developers new to Matic, start with the Matic.js library. maticjs makes it easy for developers, who may not be deeply familiar with smart contract development and otherwise, to quickly interact with the various components of Matic Network.

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

We will be improving this library on an ongoing basis to make all features available like Plasma Faster Exit, Challenge exit, Finalize exit and more.

Sidechain basics

The basic workflow of how we can scale transactions on a sidechain is that we can take

  • assets from one chain and transfer them to another (called the “sidechain")
  • by locking the assets up on the primary chain (or “root chain”) and
  • “creating” them again on the sidechain and
  • transfer assets cheaply on the sidechain.
  • When you want to go back, you simply need to “destroy” the asset on the sidechain and
  • unlock them on the root chain.

How Matic 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) within 7 days.
  • User can also get a fast exit via 0x or Dharma (coming soon!)

Important contracts and addresses

Ropsten testnet addresses

  • Ropsten MATIC ERC20 token: 0x70459e550254b9d3520a56ee95b78ee4f2dbd846
  • Root Contract: 0x60e2b19b9a87a3f37827f2c8c8306be718a5f9b4
  • DepositManager Contract: 0x4072fab2a132bf98207cbfcd2c341adb904a67e9
  • WithdrawManager Contract: 0x4ef2b60cdd4611fa0bc815792acc14de4c158d22

Matic Testnet

Faucet

You can get test MATIC tokens on Ropsten from our faucet - https://faucet.matic.network.

Install Matic.js

$ npm install --save web3 maticjs # or yarn add web3 maticjs

Note: This library is dependent on web3.js library. Tested with web3@1.0.0-beta.34

Include directly in <script>

Simply download dist/matic.js and include with a script tag. Matic will be registered as a global variable.

CDN

<script src="https://cdn.jsdelivr.net/npm/maticjs/dist/matic.js"></script>

Matic is also available on unpkg

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 withdraw-manager Address. See below for more information
  withdrawManagerAddress: <withdraw-manager-address>,

  // Set deposit-manager Address. See below for more information
  depositManagerAddress: <deposit-manager-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://matic-syncer2.api.matic.network/api/v1', // (optional)

  // Watcher API URL
  // Fetches headerBlock info from mainchain & finds appropriate headerBlock for given blockNumber
  watcherUrl: 'https://ropsten-watcher2.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
)

// get ERC721 token balance
await matic.balanceOfERC721(
  user, // User address
  tokenAddress,  // Token address
  options // transaction fields
)

// get ERC721 token ID
await matic.tokenOfOwnerByIndexERC721(
  from, // User address
  tokenAddress,  // Token address
  index, // index of tokenId
  options // transaction fields
)

// get ERC721 token ID
await matic.tokenOfOwnerByIndexERC721(
  from, // User address 
  tokenAddress,  // Token address
  index, // index of tokenId
  options // transaction fields
)

// Deposit Ether into Matic chain
await matic.depositEthers(
  options // transaction fields
)

// Approve ERC20 token for deposit
await matic.approveERC20TokensForDeposit(
  token,  // Token address,
  amount,  // Token amount for approval (in wei)
  options // transaction fields
)

// Deposit token into Matic chain. Remember to call `approveERC20TokensForDeposit` before
await matic.depositERC20Tokens(
  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
)

// Deposit ERC721 token into Matic chain.(older ERC721 or some newer contracts will not support this.
// in that case, first call `approveERC721TokenForDeposit` and `depositERC721Tokens`)
await matic.safeTransferFrom(
  token,  // Token addres
  tokenId,  // Token Id for deposit
  options // transaction fields
)

// Approve ERC721 token for deposit
await matic.approveERC721TokenForDeposit(
  token,  // Token address,
  tokenId,  // Token Id
  options // transaction fields
)


// Deposit token into Matic chain. Remember to call `approveERC721TokenForDeposit` before
await matic.depositERC721Tokens(
  token,  // Token address
  user,   // User address (in most cases, this will be sender's address),
  tokenId,  // Token Id
  options // transaction fields
)

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

// Transfer ERC721 token on Matic
await matic.transferERC721Tokens(
  token,  // Token address
  user,   // Recipient address
  tokenId,  // Token Id
  options // transaction fields
)

// Transfer Ether
await matic.transferEthers(
  user,   // Recipient address
  amount,  // Token amount
  options // transaction fields
)

// Initiate withdrawal of ERC20 from Matic and retrieve the Transaction id
await matic.startWithdraw(
  token, // Token address
  amount, // Token amount for withdraw (in wei)
  options // transaction fields
)

// Initiate withdrawal of ERC721 from Matic and retrieve the Transaction id
await matic.startERC721Withdraw(
  token, // Token address
  tokenId, // tokenId
  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
)

// Process exits after completion of challenge period
await matic.processExits(
  rootTokenAddress, // RootToken address
  options // transaction fields
)

Code Samples

Please refer https://github.com/maticnetwork/matic.js/tree/master/examples for code samples.

API


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:
  • parentProvider can be string or Web3.providers instance. This provider must connect to Ethereum chain (testnet or mainchain). Value can be anyone of following:
  • 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.
  • withdrawManagerAddress must be valid Ethereum contract address.
  • depositManagerAddress must be valid Ethereum contract address.

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.balanceOfERC721(address, token, options)

get balance of ERC721 token for address.

  • token must be valid token address
  • address must be valid user address

This returns matic balance.

Example:

matic
  .balanceOfERC721("0xfeb14bc6aaf5d39fa43ff51ed94e6c260539e296")
  .then(address => {
    console.log("matic address", address)
  })

matic.tokenOfOwnerByIndexERC721(address, token, index, options)

get ERC721 tokenId at index for token and for address.

  • token must be valid token address
  • address must be valid user address
  • index index of tokenId

This returns matic tokenId.

Example:

matic
  .tokenOfOwnerByIndexERC721("0xfeb14b...", "21", 0, {
    from: "0xABc578455..."
  })
  .then(tokenID => {
    console.log("Token ID", tokenID)
  })

matic.approveERC20TokensForDeposit(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(required)
  • 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
  .approveERC20TokensForDeposit("0x718Ca123...", "1000000000000000000", {
    from: "0xABc578455..."
  })
  .on("onTransactionHash", txHash => {
    console.log("New transaction", txHash)
  })

matic.depositERC20Tokens(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.safeTransferFrom(token, tokenId, options)

Deposit given tokenId of token.

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

Example:

matic.safeTransferFrom('0x718Ca123...', '21', {
  from: '0xABc578455...'
})

matic.approveERC721TokenForDeposit(token, tokenId, options)

Approves given amount of token to rootChainContract.

  • token must be valid ERC721 token address
  • tokenId must be tokenId (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(required)
  • 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
  .approveERC721TokenForDeposit("0x718Ca123...", "21", {
    from: "0xABc578455..."
  })
  .on("onTransactionHash", txHash => {
    console.log("New transaction", txHash)
  })

matic.depositERC721Tokens(token, user, tokenId, options)

Deposit given tokenId of token with user user.

  • token must be valid ERC721 token address
  • user must be value account address
  • tokenId must be valid tokenId
  • 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.depositERC721Tokens('0x718Ca123...', user, tokenId, {
  from: '0xABc578455...'
})

matic.depositEthers(options)

Deposit options.value

  • options see more infomation here.
  • value amount of ethers.
  • from must be valid account address(required)

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

Example:

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

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.transferERC20Tokens('0x718Ca123...', user, '1000000000000000000', {
  from: '0xABc578455...',

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

matic.transferERC721Tokens(token, user, tokenId, options)

Transfer ownership tokenId of token to user.

  • token must be valid ERC721 token address
  • user must be value account address
  • tokenId tokenId
  • 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.transferERC721Tokens('0x718Ca123...', user, tokenId, {
  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.startERC721Withdraw(token, tokenId, options)

Start withdraw process with given tokenId for token.

  • token must be valid ERC721 token address
  • tokenId must be token tokenId 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
  .startERC721Withdraw("0x718Ca123...", "21", {
    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.

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

Example:

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

matic.processExits(rootTokenAddress, options)

Call processExits after completion of challenge period, after that withdrawn funds get transfered to your account on mainchain

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

Example:

matic.processExits("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 post your queries to https://stack.matic.network 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