Providers

Providers are objects that wrap interactions with the zkSync node. If you are new to the concept of providers in web3, you should check out their docs here.

zkSync fully supports Ethereum Web3 API, so you can use the provider objects from web3.py. However, zkSync API provides some additional JSON-RPC methods, which allow:

• Easily track L1<->L2 transactions.
• Different stages of finality for transactions. By default, our RPC returns information about the last state processed by the server, but some use cases may require tracking "finalized" transactions only.

**init**

Initialize the zkSync SDK.

def __init__(self,
                 web3: Web3,
                 erc20_bridge: L1Bridge,
                 eth_bridge: L1Bridge,
                 account: BaseAccount,
                 zksync: Optional[ZkSyncContract] = None):

Arguments

Name	Description
web3	The provider instance to use for getting on-chain data.
erc20_bridge	The erc20 token address you want to bridge.
eth_bridge	The eth token address you want to bridge
account	Your wallet address used for transactions.
zksync (optional)	zkSync contract address
returns	Provider object.

approve_deposits

Bridging ERC20 tokens from Ethereum requires approving the tokens to the zkSync Ethereum smart contract, it returns the bridged erc20 token address.

def approve_deposits(self, token: Token, limit: Optional[int]) -> txn_receipt

Arguments

Name	Description
token	The Ethereum address of the token.
limit(optional)	The number of tokens to be returned from the API.

transfer

The transfer method, can transfer ETH or any ERC20 token within the same interface, and it returns the transaction receipt of the transfer.

def transfer(self, token: Token, amount: Decimal, to: HexStr) -> txn_receipt

Arguments

Name	Description
token	The address of the token. ETH by default.
to	The wallet address to transfer the tokens to
amount	The amount of tokens to transfer

Transfer a specified amount of tokens from the connected wallet to a specified address.

Example

 def transfer(self, token: Token, amount: Decimal, to: HexStr):
        if token.is_eth(): # Checks if the token is a ETH token.
            tx = {
                'nonce': self.web3.eth.get_transaction_count() + 1, #The nonce of the transaction.
                'to': to, # Address to send tokens to
                'value': Web3.toWei(amount, 'ether'), # The amount of the token sent, converted to Wei.
                'gas': self.GAS_LIMIT, # The gas limit
                'gasPrice': self.web3.eth.gas_price # The gas price of the transaction.
            }
            signed_tx = self.web3.eth.account.sign_transaction(tx, self.account)
            txn_hash = self.web3.eth.send_raw_transaction(signed_tx.rawTransaction)
            txn_receipt = self.web3.eth.wait_for_transaction_receipt(txn_hash)
            return txn_receipt # Returns the transaction receipt of the transfer.
        else:
            token_contract = ERC20Contract(web3=self.web3.eth,
                                           contract_address=token.l1_address,
                                           account=self.account,
                                           gas_provider=self.l1_erc20_bridge.gas_provider)
            return token_contract.transfer(to, token.to_int(amount)) # Returns the transaction receipt of the transfer.

get_deposit_base_cost

Returns the base cost in ETH for requesting the contract call.

def get_deposit_base_cost(self, gas_price: int = None) -> base_cost

Arguments

Name	Description
gas price	The gas price of the L1 transaction that will send the request for an execute call.

deposit

Returns the transaction receipt of the deposit.

def deposit(self, token: Token, amount: int, user_address: HexStr) -> txn_receipt

Arguments

Name	Description
token	The address of the token to deposit.
amount	The amount of the token to be deposited.
user_address	The address that will receive the deposited tokens on L2.

is_deposit_approved

Returns the transaction receipt of the allowance set.

def is_deposit_approved(self, token: Token, to: HexStr, threshold: int = DEFAULT_THRESHOLD) -> txn_receipt

Arguments

Name	Description
token	The address of the token to deposit.
to	The amount of the token to be deposited.
threshold	The daily automatic payout of all balances above your configured payout