The design principle of ERC-7802 is 'bridge agnosticism': in cross-chain scenarios, to separate token contracts from specific cross-chain bridging technologies or protocols as much as possible.
Written by: Yue Xiaoyu
To summarize, in one sentence: ERC-7802 is a cross-chain standard that extends new features for existing ERC-20 tokens, allowing standard cross-chain functionality through the ERC-7802 interface.
01 Background
ERC-7802 is a cross-chain token standard jointly proposed by the Optimism team and the Uniswap team, aimed at maintaining a unified standard for tokens during cross-chain operations.
We can see that the collaboration between Uniswap and Optimism is deepening: the Unichain that Uniswap previously announced to launch is part of the OP Superchain ecosystem, and now together they have proposed this cross-chain standard.
The introduction of ERC-7802 is aimed at standardizing cross-chain operations, which is very important for DEXs (Decentralized Exchanges) like Uniswap and L2 solutions like Optimism.
Token standards on Ethereum have been evolving, from ERC-20 to ERC-721, ERC-1155, etc. ERC-7802 is part of this evolution, focusing on solving the specific issue of cross-chain.
02 Design Principles
Overall, the design principle of ERC-7802 is 'bridge agnosticism': in cross-chain scenarios, to separate token contracts from specific cross-chain bridging technologies or protocols as much as possible.
This is a modular design that effectively transfers complexity to cross-chain bridges, separating cross-chain logic from token contracts, making the structure of token contracts simpler and more modular.
The implementation of tokens only needs to focus on their basic functions without having to consider the specific implementation of cross-chain transfers.
Bridging protocols handle all the complexities related to cross-chain transfers, including transaction verification, asset locking and releasing, cross-chain communication protocols, etc.
ERC-7802 defines a standardized interface for how tokens interact with cross-chain bridges, but does not concern itself with how these bridges are specifically implemented.
Any bridging protocol that complies with ERC-7802 can use this interface for cross-chain operations without needing to modify the token contract itself.
03 Specific Implementation
ERC-7802 defines a standardized interface that contains two key functions:
(1) crosschainMint: Mint tokens for the recipient on the target chain as a result of destroying tokens on the source chain.
(2) crosschainBurn: Destroy tokens on the source chain and initiate cross-chain transfer, usually the starting point of cross-chain transfer.
It is important to note that cross-chain minting and burning are different from local minting and burning. In cross-chain operations, the total circulating supply across all chains remains unchanged because tokens are transferred between chains rather than being truly created or destroyed.
ERC-7802 contracts support ERC-165, which is an interface detection standard that allows smart contracts to declare which interfaces they support. This helps ensure compatibility for cross-chain operation contracts.
More importantly, ERC-7802 is compatible with ERC-20.
ERC-20 is a widely used fungible token standard on Ethereum, so compatibility with the new standard and ERC-20 is very important, making it easier for existing tokens to cross-chain into the new ecosystem.
In this way, existing tokens can exist as regular ERC-20 tokens and then achieve cross-chain functionality through the ERC-7802 interface.
04 Protocol Value
Addressing the experience issues of multi-chain is a major trend; ERC-7802 actually establishes a cross-chain standard from the very bottom protocol layer, which complements the narrative of 'chain abstraction.'
ERC-7802 directly supports the goal of chain abstraction by providing a standardized cross-chain token transfer protocol, allowing assets to flow seamlessly across different chains.
The realization of chain abstraction requires the collaboration of various technical standards and protocols, and ERC-7802 can be seen as one of the key building blocks.
It can be said that ERC-7802 provides a concrete solution for chain abstraction at the technical level, addressing the technical issues of token cross-chain transfer, while chain abstraction uses these solutions to provide a higher level of user experience and application development framework.
More importantly, the standard proposed by OP also lays the foundation for interoperability within the OP Superchain ecosystem.
Currently, this protocol standard is still in discussion, and we can continue to monitor it.
