How do you withdraw from L2 to L1 using only contract calls?

[shaunkh]

Issue Description

The SDK is giving me an error: node_modules/@eth-optimism/sdk/src/utils/chain-constants.ts:53 sepolia: ethers.constants.AddressZero, ^ TypeError: Cannot read properties of undefined (reading 'AddressZero') at Object.<anonymous> (/node_modules/@eth-optimism/sdk/src/utils/chain-constants.ts:53:29)

As a result I need to test withdrawing tokens from L2 to L1 using direct contract calls. After calling withdraw on the L2StandardBridge what are the next steps?

i.e. what is the contract read I can use to proveWithdrawal?
what is the contract call I can use to finalizeWithdrawal?

And is there any other steps to it as well?

Additional Information

No response

[sbvegan]

Hey @shaunkh, this blog post will give you an overview of how two step withdrawals work. To move ETH or tokens from OP Mainnet to Ethereum you need to execute three transactions:

1. Initiate the L2 to L1 transfer on L2 chain
2. Prove the transaction on L1 (then wait for the challenge period to pass)
3. Finalize the transaction on L1

Relevant Contract

You will need to interact with the OptimismPortal on to prove and finalize. You can find the contract addresses in our documentation. With the SDK you can use:

• proveMessage
• finalizeMessage

[sbvegan]

Hey @shaunkh, I'm going to close this for now. If you have additional questions we can reopen this or you can create another post.

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