Key Differences

How EVM-compatible Cosmos chains differ from standard Cosmos chains in CosmJS.

CosmJS supports EVM-compatible Cosmos chains such as those built with Cosmos EVM (formerly Ethermint/Evmos). This section covers how EVM chains differ from standard Cosmos chains and how to use CosmJS with them.

Background

Standard Cosmos chains use secp256k1 keys, derive addresses as RIPEMD-160(SHA-256(compressedPubkey)), and hash the sign doc with SHA-256 before producing an ECDSA signature. EVM-compatible Cosmos chains use the same elliptic curve (secp256k1) but follow Ethereum conventions: addresses come from the last 20 bytes of Keccak-256(uncompressedPubkey[1:]), and the sign doc is hashed with Keccak-256 instead of SHA-256.

This means:

• The same mnemonic produces different addresses on Cosmos vs EVM chains
• Transactions must be hashed with Keccak-256 before signing
• Public keys use a different type URL in protobuf encoding
• The default HD derivation path uses coin type 60 (Ethereum) instead of 118 (Cosmos)

Comparison

Aspect	Standard Cosmos	Cosmos EVM
HD path	m/44'/118'/0'/0/0	m/44'/60'/0'/0/0
Address derivation	ripemd160(sha256(compressed))	keccak256(uncompressed[1:]).slice(-20)
Sign doc hash	SHA-256	Keccak-256
Algo identifier	"secp256k1"	"eth_secp256k1" or "ethsecp256k1"
Amino pubkey type	tendermint/PubKeySecp256k1	os/PubKeyEthSecp256k1
Protobuf type URL	/cosmos.crypto.secp256k1.PubKey	/cosmos.evm.crypto.v1.ethsecp256k1.PubKey
Wallet class	DirectSecp256k1HdWallet	DirectEthSecp256k1HdWallet
Single-key wallet	DirectSecp256k1Wallet	DirectEthSecp256k1Wallet
Gas (send)	~100,000	~120,000
Denom decimals	Typically 6	Typically 18
Amino signing	Supported	Not supported (Direct signing only)

Next Steps

EVM Wallets

Use DirectEthSecp256k1HdWallet for EVM chains.

Full Example

See a complete EVM-compatible chain integration.