Sending Chained Transactions

Chained transactions allow you to spend outputs of off-chain transactions in a sequence.

The following example, adapted from ergpy examples, demonstrates how to send chained transactions. It also includes information from GetBlok about a Transaction Group framework for sending large interrelated transactions.

Establish a Connection to the Blockchain

To begin, you need to establish a connection to the Ergo blockchain. Choose either the MainNet or TestNet node URL and set it as the node_url.

# Assign a node_url, either MainNet or TestNet
node_url: str = "http://213.239.193.208:9052/"

ergo = appkit.ErgoAppKit(node_url=node_url)

Wallet Mnemonic

Next, define your wallet mnemonic, which is a sequence of words that acts as your wallet's secret key. Replace the example wallet_mnemonic with your own mnemonic.

wallet_mnemonic = "decline reward asthma enter three clean borrow repeat identify wisdom horn pull entire adapt neglect."

receiver_addresses = [
    "3WwdXmYP39DLmDWJ6grH9ArXbWuCt2uGAh46VTfeGPrHKJJY6cSJ",
    "3WwuG9amNVDwkJdgT5Ce7aJCfeoafVmd9tag9AEiAZwgPi7pYX3w",
    "3Wxk5oofZ3Laq2CpFW4Fi9YQiaep9bZr6QFg4s4xpzz4bi9tZq2U"
]

amount = [0.22, 0.33, 0.11]

consecutive_transactions = 3

# the amount of time in seconds the program will pause in between submitting transactions
sleep_time = 0.5

# here, we calculate the number of ergs required for the genesis outbox
genesis_amount = [consecutive_transactions * (0.22 + 0.33 + 0.11) + (consecutive_transactions + 1) * 0.001]

# wallet of the sender
genesis_receiver = [""]

Create an Output Box

Create an output box for the transaction by following the code snippet below. This code returns an outbox from the signed transaction.

genesis_tx = helper_functions.simple_send(ergo=ergo, amount=genesis_amount, wallet_mnemonic=wallet_mnemonic,
                                          receiver_addresses=genesis_receiver, return_signed=True)
genesis_outbox = appkit.get_outputs_to_spend(genesis_tx, 0)

Submit the Transactions

Submit the transactions to the Ergo blockchain using the following code. This code submits the transaction to the node and prints the transaction ID (txid) to the console.

print(ergo.txId(genesis_tx))
outBox_list = []

for x in range(consecutive_transactions):
    if x == 0:  # The first transaction gets the input box from the genesis outbox
        tx_1 = helper_functions.simple_send(ergo=ergo, amount=amount, wallet_mnemonic=wallet_mnemonic,
                                            receiver_addresses=receiver_addresses, input_box=genesis_outbox,
                                            return_signed=True, chained=True)
    elif x == consecutive_transactions - 1:  # The last transaction is not chained
        tx_1 = helper_functions.simple_send(ergo=ergo, amount=

amount, wallet_mnemonic=wallet_mnemonic,
                                            receiver_addresses=receiver_addresses, input_box=outBox_list[x - 1],
                                            return_signed=True)
    else:  # Transactions in between get the input box from the prior chained transaction
        tx_1 = helper_functions.simple_send(ergo=ergo, amount=amount, wallet_mnemonic=wallet_mnemonic,
                                            receiver_addresses=receiver_addresses, input_box=outBox_list[x - 1],
                                            return_signed=True, chained=True)
    tx_1_outbox = appkit.get_outputs_to_spend(tx_1, 0)
    outBox_list.append(tx_1_outbox)
    time.sleep(sleep_time)

# Submit the final transaction to the node
print(ergo.txId(tx_1))

time.sleep(sleep_time)
helper_functions.exit()

Feel free to adjust the code to suit your specific needs.