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Creating a Simple Transaction

In this tutorial we want to create and submit a simple transaction. We assume that you have created an address key pair and the corresponding address (as explained here) and that you have some utxo at that address.

Let us assume that you want to send 100 ada from an address saved in file payment.addr to an address saved in file addr2. Let us assume that the signing key for payment.addr is in file payment.skey.

  1. We first want to calculate the necessary fees for this transaction. In order to do this, we need the protocol parameters, which we can save to file protocol.json with:

     cardano-cli shelley query protocol-parameters \
     --testnet-magic 42 \
     --out-file protocol.json

    Out simple transaction will have one input (from payment.addr) and two outputs, 100 ada to payment2.addr and the change back to payment.addr. We can calculate the fees with:

     cardano-cli shelley transaction calculate-min-fee \
     --tx-in-count 1 \
     --tx-out-count 2 \
     --ttl 250000000 \
     --testnet-magic 42 \
     --signing-key-file payment.skey \
     --protocol-params-file protocol.json

 > 167965

    (The --testnet-magic 42 identifies the FF-testnet. Other testnets will use other numbers, and mainnet uses --mainnet instead. The -ttl parameter specifies a slot number, after which this transaction is considered to be expired and will be purged from the mempool if not processed / included in a block by that slot. We are using a hard-coded large value of 250000000 for this simplistic exercise but, in real life you would most likely check the current slot number on the network, by executing 'cardano-cli shelley query tip --testnet-magic 42' command and looking at unSlotNo value in the summary returned - then adding a safety value on top of it, e.g. add 10000)

    So we need to pay 167965 lovelace fee.

    Assuming we want to spend an original utxo containing 1,000,000 ada (1,000,000,000,000 lovelace), we therefore will have:

     expr 1000000000000 - 100000000 - 167965

 > 999899832035

    change.

  2. We need the transaction hash and index of the utxo we want to spend, which we can find out as follows:

     cardano-cli shelley query utxo \
     --address $(cat payment.addr) \
     --testnet-magic 42

 >                            TxHash                                 TxIx        Lovelace
 > ----------------------------------------------------------------------------------------
 > 4e3a6e7fdcb0d0efa17bf79c13aed2b4cb9baf37fb1aa2e39553d5bd720c5c99     4     1000000000000

  3. Now we have all the information we need to create the transaction (using a "time to live" of slot 250000000, after which the transaction will become invalid) and writing the transaction to file tx001.raw).

    Note: The TTL is an absolute slot number (not relative), which means that the --ttl value should be greater than the current slot number.

     cardano-cli shelley transaction build-raw \
     --tx-in 4e3a6e7fdcb0d0efa17bf79c13aed2b4cb9baf37fb1aa2e39553d5bd720c5c99#4 \
     --tx-out $(cat payment2.addr)+100000000 \
     --tx-out $(cat payment.addr)+999899832035 \
     --ttl 250000000 \
     --fee 167965 \
     --out-file tx001.raw

  4. We need to sign the transaction with the signing key for payment.addr:

     cardano-cli shelley transaction sign \
     --tx-body-file tx001.raw \
     --signing-key-file payment.skey \
     --testnet-magic 42 \
     --out-file tx001.signed

    This writes the signed transaction to file tx001.signed.

  5. Now we can submit the transaction with:

     export CARDANO_NODE_SOCKET_PATH=db/node.socket
 cardano-cli shelley transaction submit \
     --tx-file tx001.signed \
     --testnet-magic 42

  6. We must give it some time to get incorporated into the blockchain, but eventually, we will see the effect:

     cardano-cli shelley query utxo \
     --address $(cat payment.addr) \
     --testnet-magic 42

 >                            TxHash                                 TxIx        Lovelace
 > ----------------------------------------------------------------------------------------
 > b64ae44e1195b04663ab863b62337e626c65b0c9855a9fbb9ef4458f81a6f5ee     1      999899832035

 cardano-cli shelley query utxo \
     --address $(cat payment2.addr) \
     --testnet-magic 42

 >                            TxHash                                 TxIx        Lovelace
 > ----------------------------------------------------------------------------------------
 > b64ae44e1195b04663ab863b62337e626c65b0c9855a9fbb9ef4458f81a6f5ee     0         100000000