Directory / technical-docs /

You are browsing a mirror of a file hosted on GitHub. View original

Create a simple transaction

You will need a new payment address (payment2.addr) so that you can send funds to it. First, get a new payment key pair for that:

cardano-cli shelley address key-gen \
--verification-key-file payment2.vkey \
--signing-key-file payment2.skey

This has created two new keys: payment2.vkey and payment2.skey

To generate payment2.addr we can use the same stake key pair that we already have:

cardano-cli shelley address build \
--payment-verification-key-file payment2.vkey \
--stake-verification-key-file stake.vkey \
--out-file payment2.addr \
--testnet-magic 42

Let’s send 100 ada from payment.addr to payment2.addr

Creating a transaction is a process that requires various steps:

  • Get the protocol parameters
  • Define the time-to-live (TTL) for the transaction
  • Calculate the fee
  • Build the transaction
  • Sign the transaction
  • Submit the transaction

Get protocol parameters

Get the protocol parameters and save them to protocol.json with:

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

Define the TTL (time to Live) for the transaction

We need the CURRENT TIP of the blockchain, this is, the height of the last block produced. We are looking for the value of unSlotNo

cardano-cli shelley query tip --testnet-magic 42

> Tip (SlotNo {unSlotNo = 795346}) (ShelleyHash {unShelleyHash = HashHeader {unHashHeader =        6a28a1c9fac321d7f4c8df8de68ee17f1967695460b5b422c93e6faaeeaf5cf2}}) (BlockNo {unBlockNo = 33088})

So at this moment the tip is on block 795346.

To build the transaction we need to specify the TTL (Time to live), this is the block height limit for our transaction to be included in a block, if it is not in a block by that slot the transaction will be cancelled.

From protocol.json we know that we have 1 slot per second. Lets say that it will take us 10 minutes to build the transaction, and that we want to give it another 10 minutes window to be included in a block. So we need 20 minutes or 1200 slots. So we add 1200 to the current tip: 795346 + 1200 = 796546. So our TTL is 796546.

Calculate the fee

The transaction needs one (1) input: a valid UTXO from payment.addr, and two (2) outputs: The receiving address payment2.addr and an address to send the change back, in this case we use payment.addr

   cardano-cli shelley transaction calculate-min-fee \
   --tx-in-count 1 \
   --tx-out-count 2 \
   --ttl 796546 \
   --testnet-magic 42 \
   --signing-key-file payment.skey \
   --protocol-params-file protocol.json

   > 167965

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

So we need to pay 167965 lovelace fee to create this transaction.

Assuming we want to send 100 ADA to payment2.addr spending a UTXO containing 1,000,000 ada (1,000,000,000,000 lovelace), now we need to calculate how much is the change to send back to payment.addr

expr 1000000000000 - 100000000 - 167965

> 999899832035

We need the transaction hash and index of the UTXO we want to spend:

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

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

Build the transaction

We write the transaction in a file, we will name it tx.raw.

Note that for --tx-in we use the following syntax: TxId#TxIx where TxId is the transaction hash and TxIx is the index and for --tx-out we use: TxOut+Lovelace where TxOut is the hex encoded address followed by the amount in Lovelace.

cardano-cli shelley transaction build-raw \
--tx-in 4e3a6e7fdcb0d0efa17bf79c13aed2b4cb9baf37fb1aa2e39553d5bd720c5c99#4 \
--tx-out $(cat payment2.addr)+100000000 \
--tx-out $(cat payment.addr)+999899832035 \
--ttl 796546 \
--fee 167965 \
--out-file tx.raw

Sign the transaction

Sign the transaction with the signing key payment.skey and save the signed transaction in tx.signed

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

Submit the transaction

Make sure that your node is running and set CARDANO_NODE_SOCKET_PATH variable to:

export CARDANO_NODE_SOCKET_PATH=~/cardano-node/relay/db/node.socket

and submit the transaction:

cardano-cli shelley transaction submit \
        --tx-file tx.signed \
        --testnet-magic 42

Check the balances

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