tx.md

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 addr1 to an address saved in file addr2. Let us assume that the signing key for addr1 is in file addr1.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 > protocol.json
   

   Out simple transaction will have one input (from addr1) and two outputs, 100 ada to addr2 and the change back to addr1. We can calculate the fees with:

    cardano-cli shelley transaction calculate-min-fee \
        --tx-in-count 1 \
        --tx-out-count 2 \
        --ttl 100000 \
        --testnet-magic 42 \
        --signing-key-file addr1.skey \
        --protocol-params-file protocol.json
   
    > 168141
   

   (The --testnet-magic 42 identifies the FF-testnet. Other testnets will use other numbers, and mainnet uses --mainnet instead.)

   So we need to pay 168141 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 - 168141
   
    > 999899831859
   

   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 filtered-utxo \
        --address $(cat addr1) \
        --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 100000, 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 addr2)+100000000 \
        --tx-out $(cat addr1)+999899831859 \
        --ttl 100000 \
        --fee 168141 \
        --tx-body-file tx001.raw
   

4. We need to sign the transaction with the signing key for addr1:

    cardano-cli shelley transaction sign \
        --tx-body-file tx001.raw \
        --signing-key-file addr1.skey \
        --testnet-magic 42 \
        --tx-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-filepath 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 filtered-utxo \
        --address $(cat addr1) \
        --testnet-magic 42
   
    >                            TxHash                                 TxIx        Lovelace
    > ----------------------------------------------------------------------------------------
    > b64ae44e1195b04663ab863b62337e626c65b0c9855a9fbb9ef4458f81a6f5ee     1      999899831859
   
    cardano-cli shelley query filtered-utxo \
        --address $(cat addr2) \
        --testnet-magic 42
   
    >                            TxHash                                 TxIx        Lovelace
    > ----------------------------------------------------------------------------------------
    > b64ae44e1195b04663ab863b62337e626c65b0c9855a9fbb9ef4458f81a6f5ee     0         100000000