Optimism introduces major updates to Fault Proofs, which impact recording processes for bridges and exchanges on OP Mainnet and OP Sepolia.
Optimism (OP), a leading Layer 2 scaling solution for Ethereum, will make significant breakthrough changes to the Fault Proof system, which will directly impact bridges, centralized exchanges, and custom withdrawal handling solutions. This development is crucial for stakeholders within the Optimism ecosystem as they adapt their systems to the new withdrawal verification process.
Overview of the bug-resistant system update
The upgrade introduces a shift from L2OutputOracle to a new system consisting of the OptimismPortal and DisputeGameFactory. The L2OutputOracle, previously essential to Proposer’s role in storing L2 state output proposals, will be removed entirely. Instead, developers will have to use a dispute game’s rootClaim to prove withdrawals during the first step of the two-step withdrawal process.
The OptimismPortal contract will see minor changes as it now points to the DisputeGameFactory contract instead of the L2OutputOracle. Developers should now search through the OptimismPortal for recent DisputeGame contracts with the correct game type to prove withdrawals. This shift improves the security and decentralization of the recording process, but requires developers to update their client code accordingly.
Impact on bridges and centralized exchanges
The transition to Fault Proofs requires updates to the recording processing logic. Most teams using the Optimism SDK or Viem will need to update their software versions before the Sepolia release. For example, the Optimism SDK requires an upgrade to version 3.2.0 or later, which maintains API compatibility and automatically integrates the new logic once the Fault Proof upgrade is detected.
For those using Viem, the latest version breaks the API, requiring the use of an experimental decorator that supports error trials. Once fault proofs have been integrated into the Mainnet, a move to the stable API is recommended.
Monitor system changes
The Withdrawal Monitor and Dispute Monitor services have undergone updates to accommodate the new error-proof system. The Withdrawal Monitor service, critical to the two-step recording system, has become slightly slower to start up, but more reliable and compatible with a wider range of infrastructure. It remains fully backwards compatible with existing systems.
The Dispute Monitor service, on the other hand, will replace the current Fault Monitor to detect invalid output proposals. Teams currently using the Fault Monitor will need to move to the new service and update their alert systems to remain compliant with the new upgrade.
Next steps for developers and operators
Developers and operators within the Optimism network are advised to familiarize themselves with the upcoming changes by reading Optimism’s detailed documentation. This includes understanding the three key components of the Fault Proof System – Cannon FPVM and Mips.sol – and preparing their systems for the transition.
The Fault Proof updates are expected to launch on the testnet on March 19, 2024. It is critical for all parties involved to prepare their systems in advance to ensure seamless integration with the new protocol and avoid disruptions to their operations.
Optimism continues to provide developer support to those experiencing difficulties during the transition. The proactive engagement and detailed documentation reflect Optimism’s commitment to maintaining a robust and developer-friendly ecosystem.
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