How can I create a transaction that collects inputs from many addresses and sends them to one address in bitcoind?

Question

I'm using bitcoind and would like to understand how to create transactions that send inputs from many specifically selected addresses (from my wallet) to one destination address. I want to do manually what the sendtoaddress command does automatically.

If this operation requires me to create a raw transaction could you please provide a working example? I already read bitcoin.it:raw_transactions, but it is hard to understand without an example and unfortunately the wiki article doesn't provide any.

I would appreciate help greatly.

Answer 1

When you have a bitcoin balance, that balance is actually unspent outputs from transactions your addresses have already received.

So when you want to send a raw transaction, what you include in that is the transactions and unspent outputs from those transactions... these can be from any address in your wallet.

The basic idea is;

createrawtransaction signrawtransaction sendrawtransaction

If you google around, you'll find plenty of examples of their use.

Answer 2

If this operation requires me to create a raw transaction, here's a working example assuming you have UTXOs:

UTXO 1: "txid1", Index 0, Amount 0.01 BTC
UTXO 2: "txid2", Index 1, Amount 0.02 BTC
Destination: "your_destination_address"

# Calculate transaction fee estimate (adjust the fee rate as needed)
TRANSACTION_FEE=$(bitcoin-cli estimatesmartfee 6 "CONSERVATIVE")

# Calculate total input amount from UTXOs
TOTAL_INPUT=0.03

# Calculate the desired output amount
OUTPUT_AMOUNT=0.02

# Calculate the change amount
CHANGE_AMOUNT=$(echo "$TOTAL_INPUT - $OUTPUT_AMOUNT - $TRANSACTION_FEE" | bc)

# Create the raw transaction with change output
RAW_TRANSACTION_HEX=$(bitcoin-cli createrawtransaction '[
   {"txid":"txid1", "vout":0},
   {"txid":"txid2", "vout":1}
]' '{
   "your_destination_address": '$OUTPUT_AMOUNT',
   "your_change_address": '$CHANGE_AMOUNT'
}')

# Sign the raw transaction
SIGNED_TRANSACTION_HEX=$(bitcoin-cli signrawtransactionwithwallet "$RAW_TRANSACTION_HEX")

# Broadcast the transaction
bitcoin-cli sendrawtransaction "$SIGNED_TRANSACTION_HEX"

Please correct me if I was wrong.

Answer 3

Assuming you have UTXOs:

• UTXO 1: "txid1", Index 0, Amount 0.01 BTC
• UTXO 2: "txid2", Index 1, Amount 0.02 BTC
• Destination: "your_destination_address"

# Create raw transaction
raw_tx=$(bitcoin-cli createrawtransaction '[{"txid":"txid1","vout":0}, {"txid":"txid2","vout":1}]' '{"your_destination_address": 0.03}')

# Sign raw transaction
signed_tx=$(bitcoin-cli signrawtransactionwithwallet "$raw_tx")

# Broadcast signed transaction
bitcoin-cli sendrawtransaction "${signed_tx["hex"]}"

Replace "your_destination_address" with your actual destination address. Run these commands in your terminal with your Bitcoin Core node running.

Maybe test on Bitcoin testnet before using real funds.