Automint

Python library for automating transactions on the Cardano blockchain.

• Create wallets (and associated signing and verification key files)

• Create policy scripts

  • Basic scripts
  • Time-locked multi-sig scripts

• Build, sign, and submit transactions

• Others

  • Query tip information
  • Query return address from txHash
  • Query stake key associated with address

Quick start

Creating wallets

Initialize wallets as follows

from automint.wallet import Wallet
wallet = Wallet('wallets', 'payment')

The above code will look for payment.skey and payment.vkey in wallets. If neither are found, then a new set of signing and verification keys will be generated.

Querying UTXOs in wallets

Query UTXOs as follows

utxos = wallet.query_utxo()

A list of UTXO objects will be returned, one for the contents of each UTXO found at the address.

To acquire a UTXO (for spending, as an example), use wallet.get_utxo(). If a suitable UTXO is found (contains more than 5 ADA), one will be returned. If a specific UTXO is desired or if none meet the threshold for automatic selection, pass the txHash into the function as follows wallet.get_utxo(id='<txHash>#<index>').

Token arithmetics

The intuition behind automint is to do arithmetics on UTXOs. Let's take a look at the following example

from automint.receivers import TxReceiver
receiver = TxReceiver('<wallet address>') # wallet address refers to the output address of the transaction

receiver.add_lovelace(10000000)
receiver.add_native_token('12345.sampleToken', 1)

First, we create a TxReceiver object which deals with the accounting of a receiver. A receiver represents the output of the transacion (it is the --tx-out field in the CLI command). Then, we add 10000000 lovelace and 1 sampleToken to the receiver.

Subsequently, when we convert the receiver to string representation via str(receiver), we obtain <wallet address>+10000000+"1 12345.sampleToken" which is precisely the format of the input to --tx-out.

The same goes for MintingReceiver which formats the output for the --mint argument. Any tokens that will be minted or burnt in the transaction will need to be added to MintingReceiver.

We can convert UTXO to TxReceiver objects directly by doing utxo.convert_to_receiver('<wallet address>). This instantiates a TxReceiver object but with all contents of the utxo object transferred to it. This is particularly useful when sending tokens to other addresses. Let's take a look at an example.

utxo = wallet.get_utxo() # get a UTXO to spend
receiver_a = utxo.convert_to_utxo(wallet.get_address()) # output of this part of the transaction is back to the sending address
receiver_b = TxReceiver('<receipient address>')

receiver_a.remove_lovelace(5000000)
receiver_b.add_lovelace(5000000)

Lets assume that originally, receiver_a has 10000000 lovelace and 1 token named 12345.sampleToken in the utxo. Then, at the end of the above code block, receiver_a has 5000000 lovelace and the token whilst receiver_b has 5000000 lovelace. When both are converted to string representations, we get <receiver_a address>+5000000+"1 12345.sampleToken" and <receiver_b address>+5000000 which are the exact strings needed for the respective --tx-out fields. We can also see that the balance/output of the transaction perfectly matches the input amounts.