⚠️ Upcoming RPC breaking changes in ZKsync Era

[uF4No]

We have released a platform upgrade in ZKsync Era Sepolia testnet with a breaking change that might impact some projects. Find below the details and instructions to follow if your project is affected:

Details of the change

The change applies to the transaction receipt RPC methods (eth_getTransactionReceipt, eth_getBlockReceipts), affecting contractAddress field.

• Previously, this field was set to the address of the last contract deployed by the transaction, regardless of what the transaction looks like (i.e., it was possible that it was a deployment initiated by a contract).
• After the change, this field is only set for deployment transactions, which are defined as calls to ContractDeployer.{create, create2, createAccount, create2Account} . This means that transactions to a Factory contract that calls the ContractDeployer will not include the contractAddress in their receipt, as the deployment is done as an internal call. The deployment doesn’t need to be successful for contractAddress to be set; the address is derived from the transaction and maybe storage data (such as the deployment nonce).

Additionally, EVM-like deployments (transactions where to == None) are also considered deployment transactions, but they are only supported if the EVM emulator is enabled on the chain. Currently, the emulator is NOT enabled on either the Era testnet or mainnet (more info about the emulator here).

Why is this change being made?

This update is designed to align the behavior of contractAddress with how it is handled on Ethereum (although Ethereum does not have a ContractDeployer). This is a breaking change in the RPC, so we're communicating it to teams to ensure they are aware before this change is deployed on mainnet.

When will this change be deployed on ZKsync Era mainnet?

This protocol upgrade which planned to be released on ZKsync Era mainnet in March. More specific dates will be announced closer to the date.

What do you need to do?** 

Please test your project on ZKsync Era Sepolia testnet to check if it's affected.

What's the recommended fix or workaround?

If your project uses a Factory to deploy other contracts we recommend emitting events with the contract address and reading those instead of relaying on the contractAddress field of the transaction receipt.

Let us know if you have any questions or if you need some help!