Create a Bitcoin multisig wallet from Python commandline
Follow the steps below to create a 2-of-2 multi-signature wallet from the Python commandline with a few simple steps. It assumes you have the installed the Python BitcoinLib with 'pip install bitcoinlib'.
Create some private keys
Create the first key using the Mnemonic phrase generator from BitcoinLib
>>> from bitcoinlib.mnemonic import Mnemonic
>>> p1 = Mnemonic().generate()
>>> p1
'ethics near crew genuine enter panda garment siren tumble slush nation dash'
Make sure to write down this private key passphrase on 2 or more pieces of paper and store them in a safe place.
Now preferably on another (offline) device generate a second key.
>>> from bitcoinlib.mnemonic import Mnemonic
>>> p2 = Mnemonic().generate()
>>> p2
'poem swamp inside oyster cube sign prefer scatter field health victory false'
Backup this key carefully again. We can now create a public masterkey to share with our main PC.
>>> from bitcoinlib.keys import HDKey
>>> key2 = HDKey.from_passphrase(p2, key_type='single')
>>> key2.wif()
'xpub661MyMwAqRbcFpdnKAgSoGkJoFfk6LAC7Ncewo9hUxPcQA7yCjY7k6QoMBPxYAv4RsJj3GiuDHVBeMGxABJJb5JsvxEMFwy3ekamoJLXHCc'
Share this key using a USB stick or use a library such as qrcode to create a printable and scanable code.
>>> import pyqrcode
>>> qrcode = pyqrcode.create(key2.wif())
>>> print(qrcode.terminal())
Create the multisig wallet
We are now ready to create the wallet with the private key from above and the public master key from the other PC. The first address / key is created with the new_key() method.
>>> from bitcoinlib.wallets import HDWallet
>>> wif2 = 'xpub661MyMwAqRbcFpdnKAgSoGkJoFfk6LAC7Ncewo9hUxPcQA7yCjY7k6QoMBPxYAv4RsJj3GiuDHVBeMGxABJJb5JsvxEMFwy3ekamoJLXHCc'
>>> key2 = HDKey(wif2, key_type='single')
>>> w = HDWallet.create('bitcoin-multisig-wallet', [p1, key2])
>>> >>> w.new_key()
<HDWalletKey(key_id=764, name=Multisig Key 763/755, wif=multisig-37dtoR6QrsiEZEsnarByktVRNreSC61gDf, path=m/45'/0/0/0)>
>>> w.info()
=== WALLET ===
ID 126
Name bitcoin-multisig-wallet
Owner
Scheme bip32
Multisig True
Multisig Wallet IDs 127, 128
Witness type legacy
Main network bitcoin
= Multisig Public Account Keys =
751 xpub682fymfahPiaB1nHt9JLKfBrkXdJS92LFEwjVkPMJoesjXZSG79DvmtguYDexeCvRrhETF6mcFQScZj47PBX6yR6zY8wQU1qDqEzgQEUNE1 main
756 xpub68A4hatRFDPrgWatXRoSc72bBVVnV6EiBUSsGa4uwh1ZuZNZ9BhPktWKuzY9jX2xXtoXbyu3JC9cJraQE1FM2cS3jEdVZj7LoUNGqUGPg1v main
For main keys a private master key is available in this wallet to sign transactions.
- NETWORK: bitcoin -
- - Keys
764 m/45'/0/0/0 37dtoR6QrsiEZEsnarByktVRNreSC61gDf Multisig Key 763/755 0.00000000 BTC
= Balance Totals (includes unconfirmed) =
The info() method show the 2 public master keys of this wallet. At the end of the line you find 'main' when a private key is available.
Your wallet will be stored in a Sqlite database in your home folder. You can reopen it later using the name or wallet ID.
>>> w = HDWallet('bitcoin-multisig-wallet')
>>> w = HDWallet(126)
Create a Transaction
Now fund your wallet with a small amount of bitcoins so we can create a transaction.
Update your wallet:
>>> w.utxos_update()
1
The utxos_update method returns the number of new UTXO's found, so '1' means funds received! If you call the w.info() method again you can find the details of the UTXO's and total balance available in this wallet.
Imagine you want to donate all the funds in your wallet to the Internet Archive Then you can use the wallets sweep() method to spent all UTXO's.
>>> t = w.sweep('1Archive1n2C579dMsAu3iC6tWzuQJz8dN')
>>> t.info()
Transaction 1e4e979c9622d64c51cbba0b17386e3b5a7ddfb9aad4a4ec3a935a01bff87666
Date: None
Network: bitcoin
Version: 1
Witness type: legacy
Status: new
Verified: False
Inputs
- 37dtoR6QrsiEZEsnarByktVRNreSC61gDf 388813 9b3ff0e4ebf336036a30cdf1d5ed6e45ef39d661315faed069efa3371770297b 1
legacy p2sh_multisig; sigs: 1 (2-of-2) not validated
Outputs
- 1Archive1n2C579dMsAu3iC6tWzuQJz8dN 387813 p2pkh
Size: 337
Vsize: 337
Fee: 1000
Confirmations: None
Pushed to network: False
Wallet: bitcoin-multisig-wallet
Errors: Cannot verify transaction
This will create a transaction and as you can see it could not be verified. The first input needs 2 signatures but the wallet contains only 1 private key. So we need to copy the transaction to the other PC to sign it.
>>> t.raw_hex()
'010000000...etc...5d88ac00000000'
Now on the other PC import this raw transaction and sign.
>>> t = Transaction.import_raw('010000000...etc...5d88ac00000000')
>>> t.sign(key2)
>>> t.verify()
>>> t.info()
Transaction 47f4a511aef839fa9fea9d900b1eba2866ab397fee558e8aaec3c90586072768
Date: None
Network: bitcoin
Version: 1
Witness type: legacy
Status: new
Verified: True
Inputs
- 37dtoR6QrsiEZEsnarByktVRNreSC61gDf 388813 9b3ff0e4ebf336036a30cdf1d5ed6e45ef39d661315faed069efa3371770297b 1
legacy p2sh_multisig; sigs: 2 (2-of-2) valid
Outputs
- 1Archive1n2C579dMsAu3iC6tWzuQJz8dN 387813 p2pkh
Size: 230
Vsize: 230
Fee: None
Confirmations: None
The transaction input now has 2 signatures and is ready to send. You could copy-n-paste the raw transaction and send it with a service such as https://live.blockcypher.com/btc/pushtx/ or -when the PC is online- you can send it with BitcoinLib.
>>> from bitcoinlib.service import Service
>>> Service().sendrawtransaction(t.raw())
Which will return a transaction ID when sending was successful.
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