Direct vs Amino Signing

Cosmos supports two signing modes. SigningStargateClient automatically picks the right one based on the signer you provide.

Direct (Protobuf)

The modern default. The transaction is serialized as Protobuf bytes, hashed with SHA-256, and signed. This is the most compact encoding and supports all message types.

Wallet: DirectSecp256k1HdWallet from @cosmjs/proto-signing
Interface: OfflineDirectSigner (has signDirect method)
Sign mode: SIGN_MODE_DIRECT

EVM-compatible direct wallets (DirectEthSecp256k1HdWallet, DirectEthSecp256k1Wallet) use the same Direct sign doc and the same SIGN_MODE_DIRECT, but hash the serialized bytes with Keccak-256 before signing to follow Ethereum conventions.

Amino (JSON)

The legacy format. The transaction is serialized as deterministic JSON (sorted keys, escaped special characters), hashed with SHA-256, and signed. Required for Ledger hardware wallets and some older chains.

Wallet: Secp256k1HdWallet from @cosmjs/amino
Interface: OfflineAminoSigner (has signAmino method)
Sign mode: SIGN_MODE_LEGACY_AMINO_JSON

Automatic Detection

You don’t need to choose manually. Pass any OfflineSigner to connectWithSigner and the client determines the mode at signing time:

import { isOfflineDirectSigner } from "@cosmjs/proto-signing";

// The client checks internally:
// isOfflineDirectSigner(signer) ? signDirect(...) : signAmino(...)

If your signer implements both signDirect and signAmino, Direct signing takes precedence.

CosmJS

Concepts

Guides

API Reference

Direct vs Amino Signing

Direct (Protobuf)

Amino (JSON)

Automatic Detection

​Direct (Protobuf)

​Amino (JSON)

​Automatic Detection

Direct (Protobuf)

Amino (JSON)

Automatic Detection