Migrate to v4

This guide references the major changes between v3 and v4 to help those migrating an existing app.

FeeEstimator interface updated

The IFeeEstimator interface originally included three methods for users to hook into the process to estimate the fees of an User operation. In the relay-kit new version we simplified the interface to feature only two methods that configure or update the User operation fields before and after calling the standard RPC estimation method (eth_estimateUserOperationGas). Additionally, we renamed the methods to be more descriptive.

The old interface had this 3 methods:

• setupEstimation: This method enabled updating the gas related properties as needed before calling the eth_estimateUserOperationGas method.
• adjustEstimation: This method enabled to adjust the gas related properties as needed after calling the eth_estimateUserOperationGas method.
• getPaymasterEstimation: This method was called to retrieve and adjust the paymaster related fields if we want to use the paymaster feature. It was only called when the User operation were an sponsored one.

The new interface has only two methods:

• preEstimateUserOperationGas: This method enable developers to update the gas or paymaster fields before calling eth_estimateUserOperationGas.
• postEstimateUserOperationGas: This method enable to adjust the gas or paymaster fields as needed after calling the eth_estimateUserOperationGas.

With this new API, the user can have more control over the gas estimation process and enhance the flexibility of the User operation fields that can be updated after this call.

PimlicoCustomRpcSchema only with Pimlico custom methods

We now have a separated PimlicoCustomRpcSchema that is used to define the custom RPC methods that are not part of the standard JSON-RPC methods. This schema is used to define the custom methods that are used in the Pimlico module. If you want to create your own estimator and call non-standard methods you should create your own one. Previously the PimlicoCustomRpcSchema included both the standard and custom methods.

The former PimlicoCustomRpcSchema is now Safe4337RpcSchema and includes only the standard JSON-RPC methods.

paymasterUrl is now mandatory in PaymasterOptions

Previously the paymasterUrl was only mandatory to work with sponsored User operations. Now it is mandatory to be set in the PaymasterOptions object as we are calling paymaster specific RPC methods (pm_getPaymasterStubData and pm_getPaymasterData) to fill the paymaster related fields.

Rename addModulesLibAddress

We renamed the addModulesLibAddress method to safeModulesSetupAddress to reflect the change of the Safe contract name.

Renamed EthSafeOperation

We renamed the EthSafeOperation to BaseSafeOperation so all the methods using it as a type in the Safe4337Pack will reflect this change