Accounts: L1->L2 transactions

This section explores the methods which allow the account classes to send transactions from L1 to L2.

If you want some background on how L1->L2 interaction works on zkSync, go through the introduction.

Full examples of actions below are available on the getting started page.

Deposit

func (p *DefaultEthProvider) Deposit(token *Token, amount *big.Int, address common.Address, options *GasOptions) (*types.Transaction, error)

Inputs and outputs

Name	Description
token	The address of the deposited L1 ERC20 token.
amount	The amount of the token to be deposited.
address	The address that receives the deposited tokens on L2.
options	The options for transaction fee and gas.
returns	The transaction hash of the deposit.

Claim failed deposit

The ClaimFailedDeposit method withdraws funds from an initiated deposit, which failed when finalizing on L2.
If the L2 deposit transaction fails, it sends an L1 transaction calling the ClaimFailedDeposit method of the L1 bridge, which results in returning L1 tokens back to the depositor, or throws an error.

 func (w *Wallet) ClaimFailedDeposit(depositHash common.Hash, ep EthProvider) (common.Hash, error)

Inputs and Outputs

Name	Description
depositHash	The L2 transaction hash of the failed deposit finalization.
ep	The Ethereum provider which interacts with L1 network.
returns	The transaction hash of claim failed deposit

Withdrawals

Withdrawal are executed in 2 steps:

• Withdraw: Initiates withdrawal on L2.
• FinalizeWithdraw: Finalized withdrawal on L1.

Withdraw

func (w *Wallet) Withdraw(to common.Address, amount *big.Int, token *Token, nonce *big.Int) (common.Hash, error)

Inputs and outputs

Name	Description
to	The address that receives the withdrawn tokens on L1.
amount	The amount of the token to be deposited.
token	The address of the L2 ERC20 token.
nonce	The sender's nonce.
returns	The transaction hash of the withdrawal.

FinalizeWithdraw

func (w *Wallet) FinalizeWithdraw(withdrawalHash common.Hash, index int) (common.Hash, error)

Inputs and outputs

Name	Description
withdrawalHash	The L2 transaction hash of the withdrawal.
index	The position in the L2 Merkle-tree logs of the l2Log that was sent with the message.
returns	The L1 transaction hash of the finalized withdrawal.

Example

// Perform withdraw
wHash, err := w.Withdraw(
  w.GetAddress(),
  big.NewInt(1000000000),
  nil,
  nil,
)
if err != nil {
  panic(err)
}
fmt.Println("Withdraw transaction: ", wHash)

// Wait until transaction is finalized
_, err = w.GetProvider().WaitFinalized(context.Background(), wHash)
if err != nil {
  panic(err)
}

// Perform finalize withdraw
fwHash, err := w.FinalizeWithdraw(wHash, 0)
if err != nil {
  panic(err)
}
fmt.Println("Finalize withdraw transaction", fwHash)