RIF Multisig SDK - ERC20 Transactions

ERC20 Transactions

The @rsksmart/safe-transactions-sdk package facilitates the creation of ERC20 transactions.

The ERC20TransactionBuilder provides a set of methods related to ERC20 transactions, including RIF token.

• Initialize the ERC20TransactionBuilder

  • Parameters:
    • safe: Safe - a Safe instance
    • ERC20Token: Contract - an ethers.js Contract representing the ERC20 token

  {:.snippet__parameters.snippet__parameters--lightgreen.border-bottom-0}

  import { ERC20TransactionBuilder } from '@rsksmart/safe-transactions-sdk'
  
  const erc20TransactionBuilder = ERC20TransactionBuilder.create(safe, ERC20Token)

  {:.snippet__code.snippet__code--lightgreen.border-top-0}

• Transfer transaction

  • Parameters
    • to: string - the address will receive the amount of token specified with transfer
    • transfer: BigNumber - the amount of token will be transferred to address to

  {:.snippet__parameters.snippet__parameters--lightgreen.border-bottom-0}

  const safeTransaction = await erc20TransactionBuilder.transfer(
    to,
    transfer
  )

  {:.snippet__code.snippet__code--lightgreen.border-top-0}

• TransferFrom transaction

  • Parameters
    • from: string - the address from which to transfer the amount of token specified with value
    • to: string - the address will receive the amount of token specified with transfer
    • value: BigNumber - the amount of token will be transferred to address to

  {:.snippet__parameters.snippet__parameters--lightgreen.border-bottom-0}

  const safeTransaction = await erc20TransactionBuilder.transferFrom(
    from,
    to,
    value
  )

  {:.snippet__code.snippet__code--lightgreen.border-top-0}

  To execute the transferFrom successfully, the from address should explicitly authorize the safe account to spend an amount equal to or greater than value. Such operation can be authorized through the approve method of the ERC20Token Contract.

  {:.mt-3}

  const fromToken = await MockERC20Token.connect(userFrom)
  await fromToken.approve(safe.getAddress(), value)

  {:.snippet__code.snippet__code--lightgreen}

• Approve transaction

  • Parameters
    • spender: string - the address allowed to withdraw up to the amount of token specified with amount
    • amount: BigNumber - the maximum amount allowed to be withdrawn

  {:.snippet__parameters.snippet__parameters--lightgreen.border-bottom-0}

  const safeTransaction = await erc20TransactionBuilder.approve(
    spender,
    amount,
  )

  {:.snippet__code.snippet__code--lightgreen.border-top-0}

  As stated in the EIP20 approve description: {:.mt-3}

  clients SHOULD make sure to create user interfaces in such a way that they first set the allowance to 0, before setting it to another value for the same spender.

  For further details, please read ERC20 API: An Attack Vector on Approve/TransferFrom Methods by Mikhail Vladimirov and Dmitry Khovratovich.