Atomic Swaps
In order to do an atomic swap with someone, you will first have to
agree on what tokens you wish to swap. For example purposes, let's say
you want to swap 40
ANON
(which is the balance you should have left
over after doing the payment from the previous page) for your
counterparty's 20
DAWN
. For this tutorial the counterparty is
yourself.
To protect your anonymity from the counterparty, the swap can only send entire coins. To create a smaller coin denomination, send yourself the amount you want to swap. Then check you have a spendable coin to swap with. Note that the coin overview might look very different depending on your activity:
$ ./drk wallet --coins
Coin | Spent | Token ID | Aliases | Value | Spend Hook | User Data | Spent TX
-----------------+-------+-----------------+---------+--------------------------+------------+-----------+-----------------
EGV6rS...pmmm6H | true | 241vAN...KcLssb | DRK | 2000000000 (20) | - | - | fbbd7a...5f2b19
...
H6Bc49...Zb6k8h | false | {TOKEN2} | DAWN | 2000000000 (20) | - | - | -
47QnyR...1T7igm | true | {TOKEN1} | ANON | 4269000000 (42.69) | - | - | 47b481...b07395
5UUJbH...trdQHY | false | {TOKEN1} | ANON | 4000000000 (40) | - | - | -
EEneNB...m6mxTC | false | 241vAN...KcLssb | DRK | 1999442971 (19.97253683) | - | - | -
You'll have to initiate the swap and build your half of the swap tx:
$ ./drk otc init -v 40.0:20.0 -t ANON:DAWN > half_swap
Then you can send this half_swap
file to your counterparty and they
can create the other half and sign it by running:
$ ./drk otc join < half_swap > full_swap
They can now send it back to you. Finally, to make the swap transaction valid, you need to sign it as well
$ ./drk otc sign < full_swap > signed_swap
Now that the swap is signed, one of the parties (or a third one) must attach the corresponding fee:
$ ./drk attach-fee < signed_swap > full_swap_with_fee
Since a new call has been added to the transaction, both parties must re-sign the full_swap_with_fee file, one by one.
Party A:
$ ./drk otc sign < full_swap_with_fee > signed_full_swap_with_fee
Party B:
$ ./drk otc sign < signed_full_swap_with_fee > swap.tx
Now the complete swap transaction can be broadcasted:
$ ./drk broadcast < swap.tx
[mark_tx_spend] Processing transaction: d2a5e288e6ba44583ee12db9c7a0ed154c736d1aa841d70c7d3fa121c92dfc69
[mark_tx_spend] Found Money contract in call 0
[mark_tx_spend] Found Money contract in call 1
Broadcasting transaction...
Transaction ID: d2a5e288e6ba44583ee12db9c7a0ed154c736d1aa841d70c7d3fa121c92dfc69
On success, you should see a transaction ID. This transaction will now also be in the mempool, so you should wait again until it's confirmed.
After a while you should see the change in balances in your wallet:
$ ./drk wallet --balance
Token ID | Aliases | Balance
----------------------------------------------+---------+-------------
241vANigf1Cy3ytjM1KHXiVECxgxdK4yApddL8KcLssb | DRK | 19.96835727
{TOKEN1} | ANON | 40
{TOKEN2} | DAWN | 20
Since in this example we did an atomic swap with ourself, the balances are unchanged. We can confirm it actually happened successfully by checking our coins:
$ ./drk wallet --coins
Coin | Spent | Token ID | Aliases | Value | Spend Hook | User Data | Spent TX
-----------------+-------+-----------------+---------+--------------------------+------------+-----------+-----------------
EGV6rS...pmmm6H | true | 241vAN...KcLssb | DRK | 2000000000 (20) | - | - | fbbd7a...5f2b19
...
EEneNB...m6mxTC | true | 241vAN...KcLssb | DRK | 1999442971 (19.97253683) | - | - | d2a5e2...2dfc69
H6Bc49...Zb6k8h | true | {TOKEN2} | DAWN | 2000000000 (20) | - | - | d2a5e2...2dfc69
5UUJbH...trdQHY | true | {TOKEN1} | ANON | 4000000000 (40) | - | - | d2a5e2...2dfc69
4zwzZf...uMbVir | false | {TOKEN2} | DAWN | 2000000000 (20) | - | - | -
BrqQuk...FcwW6d | false | {TOKEN1} | ANON | 4000000000 (40) | - | - | -
EEneNB...m6mxTC | false | 241vAN...KcLssb | DRK | 1999442971 (19.96834924) | - | - | -
Here you can see there are two entries for the tokens we used in the
swap: 40.00
ANON
and 20.00
DAWN
. The first entry shows the
Spent
flag as true
and the second entry shows the Spent
flag as
false
. This means the transaction was successful. Since we are
swapping with ourself, we successfully spent the coins in the first
half of the transaction, and re-minted to ourselves them in the second
half of the transaction.
If you're testing atomic swaps with a counterparty and you can see their tokens, that means the swap was successful. In case you still see your old tokens, that could mean that the swap transaction has not yet been confirmed.