Getting started: deriving addresses

This page walks through the standard key-derivation workflow: a BIP39 mnemonic in, addresses out. The same five calls are all a wallet needs for its key hierarchy; the examples below reproduce public test vectors you can check on device or simulator.

The derivation path

makeDefaultAccountPrivkey maps a mnemonic to the default account extended private key at m/44'/<coin type>/0':

Network	Coin type	Default account path
testnet	1	m/44'/1'/0'
mainnet	19788	m/44'/19788'/0'

Receiving and change keys are derived from the account key with the child-index functions:

Function	Path	Input
makeReceivingAddress(accountPrivkey, keyIndex)	<account>/0/<index>	account extended private key
makeChangeAddress(accountPrivkey, keyIndex)	<account>/1/<index>	account extended private key
makeReceivingAddressPublicKey(accountPublicKey, keyIndex)	<account>/0/<index>	account extended public key (watch-only)
makeChangeAddressPublicKey(accountPublicKey, keyIndex)	<account>/1/<index>	account extended public key (watch-only)

"Address" functions return keys

Despite their names, makeReceivingAddress and makeChangeAddress return a plain private-key blob, not an address — the names mirror the WASM exports. Convert a key to an address with pubkeyToPubkeyhashAddress (or use the …PublicKey variants from an extended public key for watch-only wallets).

Kotlin (Android)

import org.mintlayer.wallet.bindings.Network
import org.mintlayer.wallet.bindings.extendedPublicKeyFromExtendedPrivateKey
import org.mintlayer.wallet.bindings.makeDefaultAccountPrivkey
import org.mintlayer.wallet.bindings.makeReceivingAddressPublicKey
import org.mintlayer.wallet.bindings.pubkeyToPubkeyhashAddress

val mnemonic = /* the user's seed phrase */
val account = makeDefaultAccountPrivkey(mnemonic, Network.TESTNET, null)
val xpub = extendedPublicKeyFromExtendedPrivateKey(account)
val receiving0 = makeReceivingAddressPublicKey(xpub, 0u)
val address = pubkeyToPubkeyhashAddress(receiving0, Network.TESTNET)

Swift (iOS)

import MintlayerWalletBindings

let mnemonic = /* the user's seed phrase */
let account = try makeDefaultAccountPrivkey(
    mnemonic: mnemonic, network: .testnet, passphrase: nil)
let xpub = try extendedPublicKeyFromExtendedPrivateKey(accountPrivkey: account)
let receiving0 = try makeReceivingAddressPublicKey(
    accountPublicKey: xpub, keyIndex: 0)
let address = try pubkeyToPubkeyhashAddress(
    publicKey: receiving0, network: .testnet)

The optional passphrase in makeDefaultAccountPrivkey is the BIP39 passphrase: it changes the derived seed entirely and must be remembered together with the mnemonic.

Verifying against the test vectors

Running the snippet with the public BIP39 test mnemonic abandon × 23 + art (24 words, checksum valid — a public test vector, no secret material) must produce exactly:

Output	Value
Default account xpriv blob (testnet, hex)	00038000002c800000018000000012ed17c3e72223beb38ea98ec1317581f02458f02b0ecf4abe02c6490eca170a900d967bc0c84b9c2da3b55f7db9f76cbdc0469176a76d01141af2a705b4353a
Receiving public key #0 (hex)	00035a6f28253f35e2ff1ab0b086b8c87f731159661157e5be2ca98188369625dc32
Address #0 (testnet)	tmt1qyxqfq37rra32sq6zhayqcpjwh4trc07mcfardwt
Address #0 (mainnet)	mtc1q82twmwwxa3l2pe26gf0zgghu69jtez3qq2ajqyl

An account key blob can be decomposed with extendedPrivateKeyDecode, which returns the derivation path, the 32-byte chain code and the plain public/private keys; extendedPrivateKeyEncode rebuilds the canonical blob (roundtrip-safe).

Secret material

Private-key blobs and the account extended private key are secret material. Keep their lifetime short, never log them, and never present deterministic test keys like the mnemonic above as wallet seeds — anyone running the derivation has them.

Address formats

pubkeyToPubkeyhashAddress produces a Bech32 address prefixed by network: mtc1… (mainnet), tmt1… (testnet). The checksum can locate up to two mistyped characters — see address typo recovery if your app accepts pasted addresses.