Accounts

Cosmos EVM accounts are implemented to be compatible with Ethereum type addresses

Accounts in Cosmos EVM are designed for compatibility with both Ethereum and Cosmos SDK tooling. For developers interfacing with account types (e.g., during wallet integration), understanding the dual representation is essential.

References: Cosmos SDK Accounts, Ethereum Accounts

Account Structure

In the Cosmos SDK, an account designates a pair of public key (PubKey) and private key (PrivKey). The derivation path defines what the private key, public key, and address would be.

Cosmos blockchains support creating accounts with mnemonic phrases using hierarchical deterministic key generation (HD keys). HD keys generate addresses by combining the mnemonic phrase with a derivation path.

EVM Accounts

Cosmos EVM defines a custom Account type implementing an HD wallet compatible with Ethereum addresses using:

• Ethereum’s ECDSA secp256k1 curve (eth_secp265k1)
• EIP84 for full BIP44 paths
• Root HD path: m/44'/60'/0'/0 (Coin type 60 for Ethereum compatibility)

The custom EthAccount satisfies the Cosmos SDK AccountI interface with additional Ethereum-specific fields (see x/vm/types interfaces for the account keeper implementation):

// EthAccountI represents the interface of an EVM compatible account
type EthAccountI interface {
    authtypes.AccountI

    // EthAddress returns the ethereum Address representation of the AccAddress
    EthAddress() common.Address

    // CodeHash is the keccak256 hash of the contract code (if any)
    GetCodeHash() common.Hash

    // SetCodeHash sets the code hash to the account fields
    SetCodeHash(code common.Hash) error

    // Type returns the type of Ethereum Account (EOA or Contract)
    Type() int8
}

EIP-7702 Support: Cosmos EVM supports EIP-7702 code delegation, allowing EOAs to temporarily delegate code execution to smart contracts through the SetCodeHash functionality.

Address Formats

Bech32 and Hex Representations

EthAccount can be represented in both Bech32 (cosmos1...) and hex (0x...) formats for compatibility with both ecosystems.

Bech32 (default for Cosmos SDK):

cosmos1z3t55m0l9h0eupuz3dp5t5cypyv674jj7mz2jw

EIP-55 Hex (Ethereum compatibility):

0x91defC7fE5603DFA8CC9B655cF5772459BF10c6f

Public Key:

{
  "@type": "/ethermint.crypto.v1.ethsecp256k1.PubKey",
  "key": "AsV5oddeB+hkByIJo/4lZiVUgXTzNfBPKC73cZ4K1YD2"
}

Address Types

BIP-0173 defines Bech32 format with human-readable prefixes:

User Accounts (eth_secp256k1):

• Address: cosmos prefix, 20 bytes
• Pubkey: cosmospub prefix, 33 bytes (compressed)

Validator Operators (eth_secp256k1):

• Address: cosmosvaloper prefix, 20 bytes
• Pubkey: cosmosvaloperpub prefix, 33 bytes (compressed)

Consensus Nodes (ed25519):

• Address: cosmosvalcons prefix, 20 bytes
• Pubkey: cosmosvalconspub prefix, 32 bytes

Address Conversion

Convert between formats using the CLI:

# Bech32 to Hex
$ evmd debug addr cosmos1z3t55m0l9h0eupuz3dp5t5cypyv674jj7mz2jw

Address (hex): 14574A6DFF2DDF9E07828B4345D3040919AF5652
Bech32 Acc: cosmos1z3t55m0l9h0eupuz3dp5t5cypyv674jj7mz2jw
Bech32 Val: cosmosvaloper1z3t55m0l9h0eupuz3dp5t5cypyv674jjn4d6nn

Querying Accounts

Query accounts via CLI, REST, or JSON-RPC:

CLI:

evmd q auth account $(evmd keys show dev0 -a) -o json

REST API:

curl -X GET "http://localhost:10337/cosmos/auth/v1beta1/accounts/{address}"

JSON-RPC: eth_accounts, personal_listAccounts

Related Documentation

• x/vm Module - Ethereum account implementation details