What is ERC-7802 jointly proposed by Optimism and Uniswap?

Author: Yue Xiaoyu Source: X, @yuexiaoyu111

First, the conclusion, one sentence explanation: ERC-7802 is a cross-chain standard that expands new features for existing ERC-20 tokens. Calling the ERC-7802 interface can achieve standard cross-chain functions.

01 Background

ERC-7802 is a cross-chain token standard jointly proposed by the Optimism team and the Uniswap team. The goal is to allow tokens to maintain a unified standard when crossing chains.

We can see that the cooperation between Uniswap and Optimism is deepening: Unichain, which Uniswap announced before, is a member of the OP Superchain ecosystem, and now they have proposed this cross-chain standard together.

ERC-7802 was proposed to standardize cross-chain operations, which is very important for DEX (decentralized exchanges) like Uniswap and L2 solutions like Optimism.

The 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 problem of cross-chain.

02 Design Principles

Overall, the design principle of ERC-7802 is "bridge agnosticism": in cross-chain scenarios, separate token contracts from specific cross-chain bridging technologies or protocols as much as possible.

This is a modular design that actually transfers complexity to the cross-chain bridge, separates the cross-chain logic from the token contract, and makes the structure of the token contract simpler and more modular.

The implementation of the token only needs to focus on its basic functions without considering the specific implementation of the cross-chain transfer.

The bridge protocol takes on all the complexities associated with cross-chain transfers, including transaction verification, asset locking and release, cross-chain communication protocols, etc.

ERC-7802 defines a standardized interface for how tokens interact with cross-chain bridges, but does not care about how these bridges are specifically implemented.

Any bridge protocol that complies with ERC-7802 can use this interface for cross-chain operations without modifying the token contract itself.

03 Specific Implementation

ERC-7802 defines a standardized interface with two key functions:

(1) crosschainMint: mints tokens for the recipient on the target chain as a result of destroying tokens from the source chain.

(2) crosschainBurn: destroys tokens on the source chain and initiates a cross-chain transfer, usually the starting point of a cross-chain transfer.

It should be noted that cross-chain minting and burning are different from local minting and burning. In cross-chain operations, the total circulating supply on all chains remains unchanged because tokens are transferred between chains rather than actually created or destroyed.

ERC-7802 contracts support ERC-165, an interface detection standard that allows smart contracts to declare which interfaces they support. This helps ensure contract compatibility for cross-chain operations. More importantly, ERC-7802 is compatible with ERC-20. ERC-20 is a widely used homogeneous token standard on Ethereum, so it is very important that the new standard is compatible with ERC-20, so that existing tokens can be more easily cross-chained into the new ecosystem. In this way, existing tokens can exist as ordinary ERC-20 tokens, and then implement cross-chain functions through the ERC-7802 interface. 04 Protocol Value Solving the experience problem of multiple chains is a major trend. ERC-7802 actually establishes a cross-chain standard from the bottom protocol layer, which is complementary to the "chain abstraction" narrative.

ERC-7802 directly supports the goal of chain abstraction by providing a standardized cross-chain token transfer protocol, which is to enable assets to flow seamlessly on different chains.

The realization of chain abstraction requires the synergy of multiple technical standards and protocols, and ERC-7802 can be regarded as one of the key building blocks.

It can be said that ERC-7802 provides specific solutions for chain abstraction at the technical level, solving the technical problems of cross-chain transfer of tokens, 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 the interoperability of the OP Superchain ecosystem.

At present, this protocol standard is still in the discussion stage, and we can continue to pay attention.