# 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