Signing

Sign messages and transactions on Cosmos chains

Learn how to sign transactions and messages using OneKey's Cosmos provider.

---

Sign Amino (Legacy)

For legacy Amino-encoded transactions:

const chainId = 'cosmoshub-4'
const signer = 'cosmos1...'

const signDoc = {
  chain_id: chainId,
  account_number: '0',
  sequence: '0',
  fee: {
    amount: [{ denom: 'uatom', amount: '5000' }],
    gas: '200000',
  },
  msgs: [{
    type: 'cosmos-sdk/MsgSend',
    value: {
      from_address: signer,
      to_address: 'cosmos1...',
      amount: [{ denom: 'uatom', amount: '1000000' }],
    },
  }],
  memo: '',
}

const result = await provider.signAmino(chainId, signer, signDoc)

console.log({
  signed: result.signed,       // Signed document
  signature: result.signature, // { pub_key, signature }
})

---

Sign Direct (Protobuf)

For modern Protobuf-encoded transactions:

const chainId = 'cosmoshub-4'
const signer = 'cosmos1...'

const signDoc = makeSignDoc(
  bodyBytes,      // Transaction body
  authInfoBytes,  // Auth info with fee
  chainId,
  accountNumber
)

const result = await provider.signDirect(chainId, signer, signDoc)

console.log({
  signed: result.signed,
  signature: result.signature,
})

---

Sign Arbitrary Data

For signing arbitrary messages (useful for authentication):

const chainId = 'cosmoshub-4'
const signer = 'cosmos1...'
const data = 'Login to MyApp at 2024-01-01T00:00:00Z'

const signature = await provider.signArbitrary(chainId, signer, data)

// Verify the signature
const isValid = await provider.verifyArbitrary(chainId, signer, data, signature)
console.log('Signature valid:', isValid)

---

Broadcast Transaction

const chainId = 'cosmoshub-4'
const txBytes = new Uint8Array([...]) // Signed transaction bytes

// Broadcast modes: 'block', 'sync', 'async'
const result = await provider.sendTx(chainId, txBytes, 'sync')

console.log('TX Hash:', result)

---

Sign Ethereum Data

For chains that support Ethereum signing (like Evmos):

const result = await provider.signEthereum(
  chainId,
  signer,
  data,       // Message to sign
  'message'   // Type: 'message' | 'transaction'
)

console.log('Signature:', result)

---

Error Handling

try {
  await provider.enable('cosmoshub-4')
} catch (error) {
  if (error.code === 4001) {
    console.log('User rejected the request')
  } else if (error.message.includes('not supported')) {
    console.log('Chain not supported, try experimentalSuggestChain')
  } else {
    console.error('Connection failed:', error)
  }
}