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Cardano
Integrate Cardano blockchain using OneKey’s CIP-30 compatible provider. Access via window.cardano.onekey or window.cardano.nami.
OneKey implements CIP-30 (Cardano dApp Connector), for the operations documented here. It also provides Nami wallet compatibility.
Quick Links
Provider Detection
// OneKey provides both onekey and nami interfaces
const onekey = window.cardano?.onekey
const nami = window.cardano?.nami
// Check availability
if (!onekey) {
throw new Error('OneKey Cardano provider not detected')
}
// Get wallet info
console.log('Name:', onekey.name) // 'OneKey'
console.log('API Version:', onekey.apiVersion) // '0.1.0'
console.log('Icon:', onekey.icon)Quick Start
Enable Wallet
// Request wallet access
const api = await window.cardano.onekey.enable()
// Now you can use the full API
const networkId = await api.getNetworkId()
console.log('Network:', networkId === 1 ? 'Mainnet' : 'Testnet')Check if Enabled
const isEnabled = await window.cardano.onekey.isEnabled()
if (isEnabled) {
const api = await window.cardano.onekey.enable()
// Use API...
}Account Information
Get Network ID
const api = await window.cardano.onekey.enable()
const networkId = await api.getNetworkId()
// 0 = Testnet, 1 = Mainnet
console.log('Network:', networkId)Get Balance
const balance = await api.getBalance()
// Returns CBOR-encoded value (hex string)
console.log('Balance (CBOR):', balance)
// Decode using cardano-serialization-lib
import { Value, BigNum } from '@emurgo/cardano-serialization-lib-browser'
const value = Value.from_bytes(Buffer.from(balance, 'hex'))
const lovelace = value.coin().to_str()
console.log('Balance in lovelace:', lovelace) // Keep the exact integer string.Get Addresses
// Get used addresses (addresses with transaction history)
const usedAddresses = await api.getUsedAddresses()
console.log('Used addresses:', usedAddresses)
// Get unused addresses (fresh addresses)
const unusedAddresses = await api.getUnusedAddresses()
console.log('Unused addresses:', unusedAddresses)
// Get change address
const changeAddress = await api.getChangeAddress()
console.log('Change address:', changeAddress)
// Get reward/staking addresses
const rewardAddresses = await api.getRewardAddresses()
console.log('Reward addresses:', rewardAddresses)Get UTxOs
// Get all UTxOs
const utxos = await api.getUtxos()
console.log('UTxOs:', utxos)
// Get UTxOs with minimum amount
const utxosWithAmount = await api.getUtxos(
Buffer.from(Value.new(BigNum.from_str('1000000')).to_bytes()).toString('hex')
// CBOR-encoded Value for 1 ADA; import Value and BigNum from the serialization SDK.
)
// With pagination
const paginatedUtxos = await api.getUtxos(undefined, {
page: 0,
limit: 10,
})Transactions
Sign Transaction
// transaction should be CBOR-encoded hex string
const witnessSetCbor = await api.signTx(transactionCbor, partialSign)
// partialSign: boolean
// - false: reject if the wallet cannot provide every required signature
// - true: return the signatures the wallet can provide
console.log('Witness set:', witnessSetCbor)Submit Transaction
// Submit signed transaction
const txHash = await api.submitTx(signedTransactionCbor)
console.log('Transaction hash:', txHash)Build, sign, and submit
signTx returns a witness set, not a complete signed transaction. Build the unsigned transaction with a Cardano transaction library, merge the returned witnesses with its existing witness set, and submit the resulting complete transaction.
// `unsignedTransactionCbor` is a complete transaction built with current
// protocol parameters, selected inputs, outputs, fees, and change.
const witnessSetCbor = await api.signTx(unsignedTransactionCbor, false)
// Merge witnessSetCbor into the original transaction using your Cardano SDK.
// Preserve existing witnesses, scripts, datums, redeemers, and auxiliary data.
// Submit the serialized complete transaction, never witnessSetCbor alone.
const txHash = await api.submitTx(completeSignedTransactionCbor)Use the Lucid or Mesh flow below if your application does not already implement transaction construction and witness merging. These SDK examples are version-specific; follow their documentation for the version you install.
Data Signing
Sign Data (CIP-8)
Sign arbitrary data for authentication:
const api = await window.cardano.onekey.enable()
const addresses = await api.getUsedAddresses()
const address = addresses[0]
// Message to sign
const payload = Buffer.from('Hello Cardano!').toString('hex')
const signature = await api.signData(address, payload)
console.log({
signature: signature.signature, // COSE_Sign1 signature
key: signature.key, // COSE_Key public key
})Verify Signature
import { COSESign1, COSEKey } from '@emurgo/cardano-message-signing-browser'
const coseSign1 = COSESign1.from_bytes(
Buffer.from(signature.signature, 'hex')
)
const coseKey = COSEKey.from_bytes(
Buffer.from(signature.key, 'hex')
)
// Get the signed payload
const signedPayload = coseSign1.payload()
// Verify signature
// Parsing COSE is not verification. Use a CIP-8 verifier to check the
// protected headers, signing structure, payload, signature, and address binding.Event Handling
Listen for Account Changes
const api = await window.cardano.onekey.enable()
// Nami-compatible event API
api.experimental.on('accountChange', (addresses) => {
console.log('Account changed:', addresses)
})API Reference
Wallet Interface (CIP-30)
| Property/Method | Description |
|---|---|
name | Wallet name (‘OneKey’) |
icon | Wallet icon URL |
apiVersion | API version |
isEnabled() | Check if enabled |
enable() | Request wallet access |
dApp API (after enable)
| Method | Description |
|---|---|
getNetworkId() | Get network (0=testnet, 1=mainnet) |
getBalance() | Get total balance (CBOR) |
getUtxos(amount?, paginate?) | Get UTxOs |
getUsedAddresses() | Get used addresses |
getUnusedAddresses() | Get unused addresses |
getChangeAddress() | Get change address |
getRewardAddresses() | Get staking addresses |
signTx(tx, partialSign?) | Return the signed portions of a witness set |
signData(addr, payload) | Sign data (CIP-8) |
submitTx(tx) | Submit transaction |
Experimental API
| Method | Description |
|---|---|
experimental.getCollateral() | Get collateral UTxOs |
experimental.on(event, cb) | Subscribe to events |
experimental.off() | Unsubscribe |
Types
type Cbor = string // Hex-encoded CBOR
interface Paginate {
page: number
limit: number
}
interface Cip30DataSignature {
signature: string // COSE_Sign1 hex
key: string // COSE_Key hex
}
type NetworkId = 0 | 1 // 0=testnet, 1=mainnetEvents
| Event | Description |
|---|---|
accountChange | Account changed |
Error Handling
try {
const api = await window.cardano.onekey.enable()
} catch (error) {
if (error.code === -3) {
console.log('The wallet refused the request')
} else if (error.code === -4) {
console.log('The account changed; reconnect and retry')
} else {
console.error('Error:', error.message)
}
}Common Errors
| Code | Description |
|---|---|
| -1 | Invalid request |
| -2 | Internal error |
| -3 | Refused request |
| -4 | Account changed |
Using with Lucid
Lucid provides a simpler API:
npm install lucid-cardanoimport { Lucid, Blockfrost } from 'lucid-cardano'
// Initialize Lucid with OneKey
const lucid = await Lucid.new(
new Blockfrost('https://cardano-mainnet.blockfrost.io/api', 'your-api-key'),
'Mainnet'
)
// Connect OneKey
const api = await window.cardano.onekey.enable()
lucid.selectWallet(api)
// Send ADA
const tx = await lucid
.newTx()
.payToAddress('addr1...', { lovelace: 5000000n })
.complete()
const signedTx = await tx.sign().complete()
const txHash = await signedTx.submit()
console.log('TX Hash:', txHash)Using with Mesh
Mesh is another popular Cardano SDK:
npm install @meshsdk/coreimport { BrowserWallet, Transaction } from '@meshsdk/core'
// Connect to OneKey
const wallet = await BrowserWallet.enable('onekey')
// Get wallet info
const balance = await wallet.getBalance()
const addresses = await wallet.getUsedAddresses()
// Build and send transaction
const tx = new Transaction({ initiator: wallet })
.sendLovelace('addr1...', '5000000')
const unsignedTx = await tx.build()
const signedTx = await wallet.signTx(unsignedTx)
const txHash = await wallet.submitTx(signedTx)Nami Compatibility
The compatibility alias can belong to another extension. Use window.cardano.onekey to select OneKey explicitly.
// Access via Nami interface
const nami = window.cardano.nami
const api = await nami.enable()
// Same API as OneKey
const balance = await api.getBalance()