[SDK] Are there any example or notes to use a paymaster with the Rust SDK

[ETeissonniere]

Environment

Testnet

Acknowledgement

• I understand that issues are expected with the Go SDK as they are being updated.

Issue Description

We are using the Rust SDK to generate bindings on mobile and would be interested in crafting a transaction going through a paymaster. However, our engineers are a little confused as to how to craft such a tx with the Rust SDK.

Expected Behavior

There should be an example or quick documentation entry to use a custom paymaster when crafting a transaction via the Rust SDK.

Code Example

            let set_mint_result = async {
                let era_provider = zk_wallet
                    .get_era_provider()
                    .map_err(|e| format!("Failed to fetch era provider: {}", e))?;

                // set parameters for mint
                let parameters = vec![format!("{:?}", zk_wallet.l2_address()), file_url];

                // send transaction for minting
                let receipt_future = era_provider
                    .send_eip712(
                        &zk_wallet.l2_wallet,
                        contract_address,
                        "safeMint(address, string)",
                        Some(parameters),
                        None,
                    )
                    .await
                    .map_err(|e| format!("Failed to send eip712 transaction: {}", e))?;

                // get receipt
                receipt_future
                    .await
                    .map_err(|e| format!("Failed to await receipt: {}", e))?
                    .ok_or_else(|| "Transaction receipt was None".to_string())
                    .map(|receipt| {
                        log_message(
                            "DEBUG",
                            &format!("Mint transaction hash {:#?}", receipt.transaction_hash),
                        );
                        receipt
                    })
            }
            .await;

Repo Link (Optional)

No response

[dutterbutter]

Hey @ETeissonniere

You are absolutely right we should provide an example of this in the SDK example directory. Keep in mind the rust sdk is still in development. I will see if I can whip up an example for next week and post here.

Similarly to our js sdk you will need to make use of the paymaster params defined in this file and pass that along with the transaction.

[ETeissonniere]

Thanks @dutterbutter, my research shows this might be possible via a combination of the above with Eip712TransactionRequest and passed to send_transaction_eip712. Will let you know if this gets resolved before you come up with the example!

[dutterbutter]

Hey @ETeissonniere

I checked with the rust sdk maintainers, and paymaster support is not fully functional yet.

If you are up for challenge and want to contribute to add support it is open source :)

[ETeissonniere]

Happy to spend some time on this with the team. Do you have any pointers to get us started?

[dutterbutter]

@ETeissonniere that is awesome 💯 🔥 👍

I would actually first and foremost create an issue and indicate you would like to pick it up in the zksync-web3-rs repo. There the maintainers will have visibility and provide more insights!