[Application Development] How can I submit a withdrawal proof myself

[threetoeddinosaur]

Did you check the documentation?

• Yes
• No

Documentation Feedback (Optional)

Unclear on where I can find the required details to make the call proveWithdrawalTransaction on OptimismPortal contract. Also unsure if L2OutputOracle is still a valid Contract

What type of issue are you experiencing?

• Error
• Feature Request
• General Question

Issue Description

I am following the withdrawal flow as given per the documentation but instead of using the sdk for proof submittion, I am submitting the proof myself by making call to this function

function proveWithdrawalTransaction(
        Types.WithdrawalTransaction memory _tx,
        uint256 _disputeGameIndex,
        Types.OutputRootProof calldata _outputRootProof,
        bytes[] calldata _withdrawalProof
    )

of OptimismPortal2 Contract.

I am struggling with and how to achieve the values uint256 _disputeGameIndex,Types.OutputRootProof calldata _outputRootProof and bytes[] calldata _withdrawalProof

Steps to Reproduce

I called the sendMessage function on L2CrossDomainMessenger which internally calls the initializeWithdrawal function of L2ToL1MessageParser contract

Are you using a specific library or SDK?

• OP-SDK
• Viem
• Other
• Not Sure

Are you using the latest version of the library/SDK?

• Yes
• No

Environment Details

No response

Troubleshooting Attempts

No response

What type of support do you need?

• Technical support for issue resolution
• Feature implementation guidance
• General advice or consultation
• Documentation or learning resources

Additional Information

No response

Feedback

No response

[Incede]

One way to get those params would be to use viem op-stack library. I suspect the following code block in this script would get you the needed param(s).

const proveArgs = await publicClientL2.buildProveWithdrawal({
  output,
  withdrawal,
})

[threetoeddinosaur]

@Incede Hey thanks, so I am keen on not using any libraries, what is the workaround to do it without any sdks?

[threetoeddinosaur]

Also viem op-stack is using L2OutputOracle contract but on testnet it is not in use. So I am confused.