Tokens

Superchain token bridging (coming soon)

The SuperchainERC20 standard will become the default standard for issuing tokens on the Superchain once the OP Stack Interop features are live on mainnet. Currently the Superchain token bridging standard documentation is a work in progress, so please stay tuned.

The Superchain token bridging standard (SuperchainERC20) is a set of properties and an interface designed to enable ERC20 tokens to be fungible across the Superchain using the official SuperchainERC20Bridge. This standard builds upon the existing ERC20 token standard and implements the ICrosschainERC20 interface, which includes two key properties: only allowing the SuperchainERC20Bridge to call crosschainMint and crosschainBurn functions, and ensuring the token is deployed at the same address on every chain in the Superchain.

The SuperchainERC20Bridge is a predeploy that works as an abstraction on top of the L2ToL2CrossDomainMessenger for token bridging. It includes two main functions: sendERC20, which initiates a cross-chain transfer by burning tokens locally and sending a message to the target chain, and relayERC20, which processes incoming messages and mints the corresponding amount of tokens on the destination chain. This bridge utilizes the L2ToL2CrossDomainMessenger for replay protection, domain binding, and access to additional message information.

By implementing the SuperchainERC20 standard, tokens can achieve fungibility across the Superchain while maintaining a trust-minimized bridging solution. The standard's design ensures liquidity availability, which is fundamental to achieving fungibility, and removes the need for cross-chain access control lists. Additionally, the standard allows for potential future enhancements, such as cross-chain transferFrom functionality and concatenated actions for more complex cross-chain operations.