osToken ERC-20 operations

osETH and osGNO are standard ERC-20 tokens with EIP-2612 permit support. The StakeWise V3 SDK exposes the osToken contract for the configured network as sdk.contracts.tokens.mintToken, which automatically resolves to the correct address (osETH on Mainnet/Hoodi, osGNO on Gnosis Chain).

OsToken contract addresses (also available in Networks):

• osETH on Ethereum Mainnet: 0xf1C9acDc66974dFB6dEcB12aA385b9cD01190E38
• osETH on Hoodi testnet: 0x7345fC8268459413beE9e9dd327f31283C65Ee7e
• osGNO on Gnosis Chain: 0xF490c80aAE5f2616d3e3BDa2483E30C4CB21d1A0

Transfer osGNO to another address (Gnosis Chain)

import { BrowserProvider, parseEther } from 'ethers'
import { StakeWiseSDK, Network } from '@stakewise/v3-sdk'

const eip1193Provider = window.ethereum

const browserProvider = new BrowserProvider(eip1193Provider, {
  chainId: Network.Gnosis,
  name: 'gnosis',
})

const sdk = new StakeWiseSDK({
  network: Network.Gnosis,
  provider: browserProvider,
})

type Input = {
  amount: string
  userAddress: string
  toAddress: string
}

const transferOsGno = async (values: Input) => {
  const { amount, userAddress, toAddress } = values

  try {
    const value = parseEther(amount)
    const osTokenContract = sdk.contracts.tokens.mintToken

    const balance = await osTokenContract.balanceOf(userAddress)

    if (balance < value) {
      throw new Error('Insufficient osGNO balance.')
    }

    const signer = await sdk.provider.getSigner(userAddress)
    const signedContract = osTokenContract.connect(signer)

    const tx = await signedContract.transfer(toAddress, value)

    await sdk.provider.waitForTransaction(tx.hash)
  }
  catch (error) {
    console.error(error)
  }
}

transferOsGno({
  amount: '0.5', // osGNO
  userAddress: 'USER_ADDRESS',
  toAddress: 'RECIPIENT_ADDRESS',
})

Transfer osETH to another address (Ethereum Mainnet)

The same code works on Ethereum — only the network in the SDK constructor changes. sdk.contracts.tokens.mintToken automatically resolves to the osETH contract.

import { BrowserProvider, parseEther } from 'ethers'
import { StakeWiseSDK, Network } from '@stakewise/v3-sdk'

const eip1193Provider = window.ethereum

const browserProvider = new BrowserProvider(eip1193Provider, {
  chainId: Network.Mainnet,
  name: 'mainnet',
})

const sdk = new StakeWiseSDK({
  network: Network.Mainnet,
  provider: browserProvider,
})

type Input = {
  amount: string
  userAddress: string
  toAddress: string
}

const transferOsEth = async (values: Input) => {
  const { amount, userAddress, toAddress } = values

  try {
    const value = parseEther(amount)
    const osTokenContract = sdk.contracts.tokens.mintToken

    const balance = await osTokenContract.balanceOf(userAddress)

    if (balance < value) {
      throw new Error('Insufficient osETH balance.')
    }

    const signer = await sdk.provider.getSigner(userAddress)
    const signedContract = osTokenContract.connect(signer)

    const tx = await signedContract.transfer(toAddress, value)

    await sdk.provider.waitForTransaction(tx.hash)
  }
  catch (error) {
    console.error(error)
  }
}

transferOsEth({
  amount: '0.5', // osETH
  userAddress: 'USER_ADDRESS',
  toAddress: 'RECIPIENT_ADDRESS',
})

Approve a spender (e.g. a DeFi protocol)

import { BrowserProvider, parseEther } from 'ethers'
import { StakeWiseSDK, Network } from '@stakewise/v3-sdk'

const eip1193Provider = window.ethereum

const browserProvider = new BrowserProvider(eip1193Provider, {
  chainId: Network.Mainnet,
  name: 'mainnet',
})

const sdk = new StakeWiseSDK({
  network: Network.Mainnet,
  provider: browserProvider,
})

type Input = {
  amount: string
  userAddress: string
  spenderAddress: string
}

const approveOsToken = async (values: Input) => {
  const { amount, userAddress, spenderAddress } = values

  try {
    const value = parseEther(amount)
    const osTokenContract = sdk.contracts.tokens.mintToken

    const signer = await sdk.provider.getSigner(userAddress)
    const signedContract = osTokenContract.connect(signer)

    const tx = await signedContract.approve(spenderAddress, value)

    await sdk.provider.waitForTransaction(tx.hash)
  }
  catch (error) {
    console.error(error)
  }
}

approveOsToken({
  amount: '1.0', // osETH
  userAddress: 'USER_ADDRESS',
  spenderAddress: 'SPENDER_CONTRACT_ADDRESS',
})

Read balance and allowance

import { StakeWiseSDK, Network } from '@stakewise/v3-sdk'
import { formatEther } from 'ethers'

const sdk = new StakeWiseSDK({
  network: Network.Mainnet,
  endpoints: {
    web3: 'https://mainnet.infura.io/v3/...',
  },
})

type Input = {
  ownerAddress: string
  spenderAddress: string
}

const readOsTokenState = async (values: Input) => {
  const { ownerAddress, spenderAddress } = values

  try {
    const osTokenContract = sdk.contracts.tokens.mintToken

    const [ balance, allowance ] = await Promise.all([
      osTokenContract.balanceOf(ownerAddress),
      osTokenContract.allowance(ownerAddress, spenderAddress),
    ])

    console.log('osETH balance:', formatEther(balance))
    console.log('osETH allowance:', formatEther(allowance))
  }
  catch (error) {
    console.error(error)
  }
}

readOsTokenState({
  ownerAddress: 'USER_ADDRESS',
  spenderAddress: 'SPENDER_CONTRACT_ADDRESS',
})