@sei-js/ledger

TypeScript library for SEI Ledger app helper functions — address derivation, Amino signing, and CosmJS integration

The @sei-js/ledger package provides TypeScript helper functions for the SEI Ledger hardware wallet app. It enables address derivation and offline Amino signing for Cosmos-side transactions on Sei.

For EVM-side transaction signing with Ethers.js, see the Ledger Setup (EVM) guide instead.

Installation

npm install @sei-js/ledger

Hardware Requirements

• Ledger Nano S Plus, Nano X, or compatible device
• SEI app installed on the Ledger device (via Ledger Live Manager)
• USB or Bluetooth connection to your computer

Core Functions

createTransportAndApp

Creates a transport connection and app instance for communicating with the Ledger device.

import { createTransportAndApp } from '@sei-js/ledger';

const { transport, app } = await createTransportAndApp();

Returns: Promise<{ transport: Transport, app: SeiApp }>

getAddresses

Retrieves both EVM and Cosmos addresses from the Ledger device for a given derivation path.

import { createTransportAndApp, getAddresses } from '@sei-js/ledger';

const { app } = await createTransportAndApp();
const { evmAddress, nativeAddress } = await getAddresses(app, "m/44'/60'/0'/0/0");

console.log('EVM address:', evmAddress);
console.log('Sei address:', nativeAddress);

Parameters:

Parameter	Type	Description
app	SeiApp	Ledger Sei app instance
path	string	HD derivation path (e.g. "m/44'/60'/0'/0/0")

Returns: Promise<{ evmAddress: string, nativeAddress: string }>

SeiLedgerOfflineAminoSigner

A signer class compatible with CosmJS that enables offline Amino signing via Ledger.

import { SeiLedgerOfflineAminoSigner } from '@sei-js/ledger';

const ledgerSigner = new SeiLedgerOfflineAminoSigner(app, "m/44'/60'/0'/0/0");

Constructor Parameters:

Parameter	Type	Description
app	SeiApp	Ledger Sei app instance
path	string	HD derivation path

getAccounts

Retrieves account information from the Ledger device.

const accounts = await ledgerSigner.getAccounts();
// [{ address: 'sei1...', pubkey: { type: 'tendermint/PubKeySecp256k1', value: '...' } }]

signAmino

Signs a transaction document using the Ledger device. The device will prompt for physical confirmation.

import { StdSignDoc } from '@cosmjs/amino';

const signDoc: StdSignDoc = {
  /* your transaction document */
};
const { signed, signature } = await ledgerSigner.signAmino('sei1...', signDoc);

Complete Example: Delegating Tokens

import { coins, SigningStargateClient, StdFee } from '@cosmjs/stargate';
import { createTransportAndApp, getAddresses, SeiLedgerOfflineAminoSigner } from '@sei-js/ledger';

async function delegateWithLedger() {
  const rpcUrl = 'https://rpc-testnet.sei-apis.com/';
  const path = "m/44'/60'/0'/0/0";

  const { app } = await createTransportAndApp();
  const { nativeAddress } = await getAddresses(app, path);
  const ledgerSigner = new SeiLedgerOfflineAminoSigner(app, path);

  const client = await SigningStargateClient.connectWithSigner(rpcUrl, ledgerSigner);

  const msgDelegate = {
    typeUrl: '/cosmos.staking.v1beta1.MsgDelegate',
    value: {
      delegatorAddress: nativeAddress.address,
      validatorAddress: 'seivaloper1...',
      amount: coins(500, 'usei')
    }
  };

  const fee: StdFee = {
    amount: [{ denom: 'usei', amount: '20000' }],
    gas: '200000'
  };

  const result = await client.signAndBroadcast(nativeAddress.address, [msgDelegate], fee, 'Delegation via Ledger');

  console.log('Broadcast result:', result);
}

delegateWithLedger();

Security

• Ensure your Ledger device is genuine and purchased from official sources
• Always verify transaction details on the Ledger screen before confirming
• Keep your Ledger firmware and the SEI app updated
• Store your recovery phrase securely and never share it