Basic Payment Transaction

We use the command pay to make a simple payment.

zcash-warp〉help pay                                      09/23/2024 02:43:11 PM
Usage: pay <ACCOUNT> <ADDRESS> <TO_POOLS> <AMOUNT> <FROM_POOLS> <FEE_PAID_BY_SENDER> <USE_CHANGE>

Arguments:
  <ACCOUNT>
  <ADDRESS>
  <TO_POOLS>
  <AMOUNT>
  <FROM_POOLS>
  <FEE_PAID_BY_SENDER>
  <USE_CHANGE>

Options:
  -h, --help  Print help

account: Account number where to take the funds from
address: Address where we send the funds to
to_pools: Pool mask applied on the previous address that restricts the receivers. For example, if you specify a UA that has T+S+O and use a to_pools of 1, the transaction will send to the transparent receiver^[1].
amount: The amount in ZATS
from_pools: Similar to to_pools but indicates the pools to take funds from.
fee_paid_by_sender: 1 or 0. A value of 1 means that we pay the transaction fee. A value 0 means the recipient pays. In the later case, the amount received will be less than specified.
use_change: 1 or 0. 1 means that the transaction included a change output. Most of the time, we should use a change output otherwise the transaction cannot be built.

Second Account

Let's create a second account. We'll make a basic transfer to it.

Generate a new seed or use this one: title fork smoke flash network submit happy jar repair glance narrow spell hammer language practice salad curious zebra crane table dynamic salon vintage avoid

zcash-warp〉account create "title fork smoke flash network submit happy jar repair glance narrow spell hammer language practice salad curious zebra crane table dynamic salon vintage avoid" "TEST" 1

This is our second account.

zcash-warp〉account list                                  09/23/2024 02:55:37 PM
[
  {
    "coin": 0,
    "id": 1,
    "key_type": 127,
    "name": "DEMO",
    "birth": 1,
    "balance": 624985000
  },
  {
    "coin": 0,
    "id": 2,
    "key_type": 127,
    "name": "TEST",
    "birth": 1,
    "balance": 0
  }
]

Grab the Orchard address of the second account

zcash-warp〉address 2 4                                   09/23/2024 02:56:27 PM
Address: uregtest1x2c8rjte4uqpus002dfjul72h42yc6mw6npj08e7shnl0wjdvfl2f7a7x6vuh0k9l2gfdc55gsdv7xfydwp4cvheqxrj2hccpgmy5cpt

Let's make a payment from account 1 to account 2 of 1 ZEC.

zcash-warp〉pay 1 zregtestsapling154t4hyfhzjn7pdtyfs9znamk872krs239jzgmr5fnp98u8gqmhndc28c3el0k95d7reus097upc 7 100000000 7 1 1
{
  "height": 102,
  "recipients": [
    {
      "address": "zregtestsapling154t4hyfhzjn7pdtyfs9znamk872krs239jzgmr5fnp98u8gqmhndc28c3el0k95d7reus097upc",
      "amount": 100000000,
      "change": false
    },
    {
      "address": "uregtest1qae0mnr0p9jenge23nc47f359kwkyqvq0kl3qfgyqmk5k37jcvqlzafype9r99yxwfhs38q3w0a2qgam489deht2fguv6hg6g5m0c5vk",
      "amount": 524965000,
      "change": true
    }
  ],
  "transparent_ins": 0,
  "sapling_net": -100000000,
  "orchard_net": 100020000,
  "fee": 20000,
  "privacy_level": 2,
  "num_inputs": [
    0,
    0,
    1
  ],
  "num_outputs": [
    0,
    1,
    1
  ],
  "data": null,
  "keys": null
}

INFO

The previous command means to "pay address ureg.. (use any receiver) an amount of 1 ZEC using any of our notes (any source pool). We'll pay for the transaction fee and use a change if necessary".

The wallet replied with a transaction description. However the transaction is not published yet.

Recipients

In the recipients section, we see the two outputs. The first one is the payee information: address, amount & memo. The second recipient is our own source address and corresponds to the change.

We have a note of ~6.25 ZEC. Notes are not divisible. They must always be spent fully. Therefore, we are bringing 6.25 ZEC in. If we don't include a change output, the difference would go to the miner. The wallet app adds a change output because use_change is 1. However, if we used 0, zcash-warp will refuse to make this transaction because the change cannot go anywhere.

  "transparent_ins": 0,
  "sapling_net": -100000000,
  "orchard_net": 100020000,
  "fee": 20000,

This section describes the amount going in and out of each pool.

WARNING

All the transparent data is public and the net change of the shielded pools is also public.

This transaction does not have any transparent data, it is fully shielded.

However, we can see that sapling_net and orchard_net are not 0. sapling_net is -100000000: 1 ZEC is going into the Sapling pool. orchard_net is 100020000: 1 ZEC (+20000 ZATS) is going out of the Orchard pool.

We can expect that since our wallet only has an Orchard note, and we are sending to a Sapling address.

1 ZEC went through the turnstile. This information is public.

INFO

The address and amount spent and sent to shielded addresses are hidden.

Privacy level

The privacy level is a measure of how much information is revealed by your transaction.

  "privacy_level": 2,

Privacy Level
0	The transaction has both transparent inputs and outputs
1	The transaction has either transparent inputs or outputs
2	The transaction has no transparent components but a significant amount
	of funds is going through the turnstile
3	The transaction reveals minimum information. Only the fees is public

Number of inputs and outputs per pool

  "num_inputs": [
    0,
    0,
    1
  ],
  "num_outputs": [
    0,
    1,
    1
  ],

This shows that the transaction has 1 orchard input, 1 sapling output and 1 orchard output. The number of inputs and outputs determine the fees.

ZIP 317

We calculate the fees by multiplying the number of logical actions by their unit price of 5000 ZATS.

The total number of logical actions (TLA) is the sum of transparent LA, sapling LA and orchard LA.

For each pool, the LA is the MAX between the number of inputs and outputs.

In our example, there are no transparent inputs and outputs, TLA = 0. There is 0 sapling input and 1 sapling output, SLA = 1. There is 1 orchard input and 1 orchard output, OLA = 1.

WARNING

However, for SLA and OLA, the minimum value (if not 0) is TWO^[2].

Therefore, the real value for SLA is 2. The same applies to OLA.

Finally, the TLA = 0 + 2 + 2 = 4

The fee is 4 x 5000 = 20000.

We will keep analyzing our transaction plans in the following sections.

Let's execute this transaction now.

zcash-warp〉broadcast-latest                              09/23/2024 03:33:18 PM
"a782d0b23b61fea589be9798e5f3498c3508bf5a40ef18392586ca4eb1450542"

Your transaction ID will be different from this one.

zcash-warp sent the transaction to LWD. LWD relayed it to zcashd. It is now in the mempool. As always, we need to mine a block to get it included in the blockchain.

$ ./src/zcash-cli --datadir=regtest_dir generate 1

And then sync our wallet to get the updated state.

zcash-warp〉sync                                          09/23/2024 03:35:58 PM
zcash-warp〉balance 2                                     09/23/2024 03:36:00 PM
Balance: BalanceT { transparent: 0, sapling: 100000000, orchard: 0 }
zcash-warp〉balance 1                                     09/23/2024 03:36:20 PM
Balance: BalanceT { transparent: 0, sapling: 0, orchard: 524965000 }
zcash-warp〉                                              09/23/2024 03:36:20 PM

Account #2 has 1 ZEC in the sapling pool and Account #1 has 5.25 ZEC in Orchard.

Next, we will make a transaction that has more than one recipient in order to split our 5.25 ZEC into smaller denominations.

The pool mask is the sum of 3 values. 1 for Transparent, 2 for Sapling and 4 for Orchard. ↩︎
This is due to the padding introduced by the transaction builder. The resulting transaction has dummy inputs and outputs that you have to pay. ↩︎

Basic Payment Transaction ​

Second Account ​

Recipients ​

Privacy level ​