import Methods from '@stakewise/methods'

const methods = new Methods({
  provider, // ethers provider - https://docs.ethers.io/v5/api/providers/provider/
  sender, // wallet address
  referrer, // referrer address (optional)
})

Fetching token balances

Method getBalances returns balances of SWISE tokens, staked tokens, reward tokens and native tokens.

A balance for every token it is an object called below as TokenValue. It contains properties:

value - token balance in BigNumber
and fiatValues - object that contains fiat values in USD, EUR and GBP

type TokenValue = {
  value: BigNumber
  fiatValues: {
    usd: number
    eur: number
    gbp: number
  }
}

try {
  const balances = await methods.getBalances()

  const {
    swiseTokenBalance, // TokenValue with amount of SWISE 
    stakedTokenBalance, // TokenValue with amount of staked tokens (e.g. sETH2)
    rewardTokenBalance, // TokenValue with amount of reward tokens (e.g. rETH2)
    nativeTokenBalance, // TokenValue with amount of native tokens (e.g. ETH)
  } = balances

  // Formatted balance of native tokens (e.g. 0.318871759160055215)
  const nativeTokenValue = formatEther(nativeTokenBalance.value)

  // Formatted balance in USD (e.g. $956.35)
  const nativeTokenFiatValue = `$${nativeTokenBalance.fiatValues.usd}`
} catch (error) {
  console.error(error)
}

Click to read how it works

To get balances we make requests:

Get native token balance: provider.getBalance(sender)
Get staked token balance: stakedTokenContract.balanceOf(sender) Staked token contract address: 0xFe2e637202056d30016725477c5da089Ab0A043A
Get reward token balance: rewardTokenContract.balanceOf(sender) Reward token contract address: 0x20BC832ca081b91433ff6c17f85701B6e92486c5
Get SWISE token balance: swiseTokenContract.balanceOf(sender) SWISE token contract address: 0x48C3399719B582dD63eB5AADf12A40B4C3f52FA2
Get fiat rates to calculate fiat balances: Promise.all([ ethUsd.latestAnswer(), eurUsd.latestAnswer(), gbpUsd.latestAnswer(), ])

EthUsd rate contract address: 0x5f4eC3Df9cbd43714FE2740f5E3616155c5b8419

EurUsd rate contract address: 0xb49f677943BC038e9857d61E7d053CaA2C1734C1

GbpUsd rate contract address: 0x5c0Ab2d9b5a7ed9f470386e82BB36A3613cDd4b5

Fetching staking APR

StakingApr is a number of the annual yield percent.

try {
  const stakingApr = await methods.getStakingApr()
} catch (error) {
  console.error(error)
}

Click to read how it works

Reward token contract address: 0x20BC832ca081b91433ff6c17f85701B6e92486c5

Get reward token protocol fee: rewardTokenContract.protocolFee()
Get pool stats: https://api.stakewise.io/pool-stats/ Returns object with validatorsAPR number

Staking APR calculation:

const { validatorsAPR } = poolStats

const maintainerFee = protocolFee.toNumber()
const stakingAPR = validatorsAPR - validatorsAPR * (maintainerFee / 10_000)

Deposit

The deposit method allows sending available amount of native tokens (e.g. ETH) and receiving as the result staked tokens (e.g. sETH2).

Staked tokens by default will be submitted to the sender wallet, but could be submitted to another wallet (if address is provided).

try {
  const transaction = await methods.deposit({
    amount, // BigNumber with amount to deposit
    address, // Optional recipient wallet address (current wallet address by default)
  })
  
  // Wait for transaction confirmation
  if (transaction && transaction.hash) {
    await provider.waitForTransaction(transaction.hash)
  }
} catch (error) {
  console.error(error)
}

Click to read how it works

Pool contract address: 0xC874b064f465bdD6411D45734b56fac750Cda29A

First we are estimating gas, and after that sending deposit.

To estimate gas we call this.provider.getFeeData() to get { maxFeePerGas, maxPriorityFeePerGas } and call pool contract gas estimation method.

Depending on provided referrer and receiver addresses there are different methods should be called.

Gas estimation with referrer

On each call we have to provide parameters:
from which is the sender address,
and value which is the BigNumber amount to deposit.

If receiver address is the same as the address of the current wallet, we call:

poolContract.estimateGas.stakeWithReferrer(referrer, { from, value })

If not, we provide receiver address and call:

poolContract.estimateGas.stakeWithReferrerOnBehalf(referrer, address, { from, value })

Gas estimation without referrer

If receiver address is the same as the current wallet address, we call:

poolContract.estimateGas.stake({ from, value })

If receiver address is not the same as the current wallet address, we call:

poolContract.estimateGas.stakeOnBehalf(address, { from, value })

As the result in each case we'll receive gasLimit (BigNumber). This value we increase on 1000 to be able to spend a bit more gas if it will be needed:

const gasLimit = await estimateGas()

return gasLimit
  .mul(10000)
  .add(1000)
  .div(10000)

The next step is to send deposit, to make the deposit call we need to create a signed contract:

const signer = provider.getUncheckedSigner(address)
const signedContract = poolContract.connect(signer)

Now, after gas estimation we have:

maxFeePerGas: null | BigNumber
maxPriorityFeePerGas: null | BigNumber
gasLimit: BigNumber

We need to provide these parameters to the next contract call to send deposit.

The call is similar to gas estimation since it has different methods that should be called depending on provided referrer and receiver addresses.

Deposit with referrer

If receiver address is the same as the current wallet address, we call:

signedContract.stakeWithReferrer(referrer, { maxFeePerGas, maxPriorityFeePerGas, gasLimit })

If not, we provide receiver address and call:

signedContract.stakeWithReferrerOnBehalf(referrer, address, { maxFeePerGas, maxPriorityFeePerGas, gasLimit })

Deposit without referrer

If receiver address is the same as the current wallet address, we call:

signedContract.stake({ maxFeePerGas, maxPriorityFeePerGas, gasLimit })

If receiver address is not the same as the current wallet address, we call:

signedContract.stakeOnBehalf(address, { maxFeePerGas, maxPriorityFeePerGas, gasLimit })

As the result in each case we'll receive ContractTransaction. We can wait until transaction will be confirmed and after that we can call getBalances() to update balances