--- eip: 3770 title: Chain-specific addresses description: Prepending chain-specific addresses with a human-readable chain identifier author: Lukas Schor (@lukasschor), Richard Meissner (@rmeissner), Pedro Gomes (@pedrouid), ligi discussions-to: https://ethereum-magicians.org/t/chain-specific-addresses/6449 status: Draft type: Standards Track category: ERC created: 2021-08-26 --- ## Abstract [ERC-3770](./eip-3770.md) introduces a new address standard to be adapted by wallets and dApps to display chain-specific addresses by using a human-readable prefix. ## Motivation The need for this proposal emerges from the increasing adoption of non-Ethereum Mainnet chains that use the Ethereum Virtual Machine (EVM). In this context, addresses become ambiguous, as the same address may refer to an EOA on chain X or a smart contract on chain Y. This will eventually lead to Ethereum users losing funds due to human error. For example, users sending funds to a smart contract wallet address which was not deployed on a particular chain. Therefore we should prefix addresses with a unique identifier that signals to Dapps and wallets on what chain the target account is. In theory, this prefix could be a [EIP-155](./eip-155.md) chainID. However, these chain IDs are not meant to be displayed to users in dApps or wallets, and they were optimized for developer interoperability, rather than human readability. ## Specification This proposal extends addresses with a human-readable blockchain short name. ### Syntax A chain-specific address is prefixed with a chain shortName, separated with a colon sign (:). Chain-specific address = "`shortName`" "`:`" "`address`" - `shortName` = STRING - `address` = STRING ### Semantics * `shortName` is mandatory and MUST be a valid chain short name from https://github.com/ethereum-lists/chains * `address` is mandatory and MUST be a [ERC-55](./eip-55.md) compatible hexadecimal address ### Examples ![Chain-specific addresses](../assets/eip-3770/examples.png "Examples of chain-specific addresses") ## Rationale To solve the initial problem of user-facing addresses being ambiguous in a multichain context, we need to map EIP-155 chain IDs with a user-facing format of displaying chain identifiers. ## Backwards Compatibility Ethereum addresses without the chain specifier will continue to require additional context to understand which chain the address refers to. ## Security Considerations Similar looking chain short names can be used to confuse users. ## Copyright Copyright and related rights waived via [CC0](../LICENSE.md).