# L2 Interop Working Group - Call #8 **April 30th, 2025** - [Recording](https://youtu.be/cztPD76q2as) - [Calendar invite for future calls](https://docs.google.com/forms/d/e/1FAIpQLSfMFEJmyVgjLuiipgxprEkiQXwwK3F_PfGbWvU8ZmV6e_ka0A/viewform) ### [Agenda](https://github.com/ethereum/pm/issues/1509) 1. Chain-specific addresses aka "Interoperable addresses" ([ERC-7828](https://github.com/ethereum/ERCs/pull/735) and [ERC-7930](https://github.com/ethereum/ERCs/pull/1002)) ## Call Notes *condensed notes below – watch the recording (above) for full discussion* ### TL;DR - Chain-specific addresses (aka "interoperable addresses") have been revamped from the original ERC-7828 design, led by Wonderland team in collaboration with co-authors from wallet teams, L2s, and ENS - Original ERC is now split into two: - [ERC-7828](https://github.com/ethereum/ERCs/pull/735): human-readable names for Interoperable Addresses - [ERC-7930](https://github.com/ethereum/ERCs/pull/1002): interoperable addresses: extensible binary format to refer to an address specific to one chain ### Overview of Interoperable Addresses Standards - Two complementary standards being developed: 7828, which builds off of 7930 - Comprehensive overview available at: [https://defi-wonderland.notion.site/Our-efforts-with-ERC-7828-and-ERC-7930-1d79a4c092c78007a0b1f8098cad5ffc](https://defi-wonderland.notion.site/Our-efforts-with-ERC-7828-and-ERC-7930-1d79a4c092c78007a0b1f8098cad5ffc) ### Evolution of the Standards - Initial attempts tried combining binary and text representation in one format - Challenges due to different requirements from wallets vs message passing protocols - Decision made to split into two separate standards to better serve different use cases: - Smart contracts/cross-chain messaging (ERC-7930) - Human-readable format for wallets and UIs (ERC-7828) ### Technical Details of ERC-7930 (Binary Format) - Designed for smart contracts and intents/cross-chain messaging frameworks - Binary payload structure: - Version field (for future extensions) - Chain Type (matches namespace) - Chain Reference (specific chain within ecosystem) - Address field - Basic text representation format (checksum only used in text representation, not in binary) - Supports all chains in Ethereum ecosystem (including non-EVM) ### ERC-7828 Features and Implementation - Focuses on human-readable format - Supports hierarchical names within address/chain fields - Top-level domains (TLDs) define resolution methods - Compatibility considerations: - Works with ENS and potential future naming systems - Maintains centralized registry of chain names temporarily - Plans to transition to decentralized chain naming (ERC-7785) - Timeline: Aiming for final call status within 2 weeks - Additional resources and FAQ regarding CAIP-10 compatibility: [https://defi-wonderland.notion.site/RFC-Universal-Address-Formats-for-Interoperability-ERC-7828-ERC-7930-1e09a4c092c78084b56ed8a3b20aa098](https://defi-wonderland.notion.site/RFC-Universal-Address-Formats-for-Interoperability-ERC-7828-ERC-7930-1e09a4c092c78084b56ed8a3b20aa098) ### Next Steps and Discussion Points - Resolve address format concerns (email collision) - ethmagicians discussion forum for additional feedback - Implementation considerations for wallets and naming registries being finalized