atomic-swap/docs/local.md

Trying the swap locally

Requirements

• go 1.18+ (see build instructions to download Go.)
• ganache (can be installed with npm install --location=global ganache)

These programs and scripts have only been tested on X86-64 Ubuntu 20.04 and 22.04. Using nvm is the suggested way to install npm. If you install npm using a package manager like snap, ensure the install prefix (npm config get prefix) is a directory that you have write access to without sudo. You can change the directory with the command npm config set prefix ~/.npm-packages. See this document if you want a more sophisticated setup.

Set up development environment

Note: the scripts/install-monero-linux.sh script will download the monero binaries needed for you. You can invoke it directly, but the next script below will run it if there is no symbolic link named monero-bin to a monero installation in the project's root directory.

Execute the scripts/setup-env.sh script to launch ganache, an ethereum simulator, and monerod in regtest mode. "regtest" mode is stand-alone (non-networked) mode of monerod for testing purposes.

Build and run

Build binary:

make build

This creates swapd and swapcli binaries in the root directory.

To run as Alice, execute in terminal 1:

./swapd --dev-xmrtaker

Alice will print out a libp2p node address, for example /ip4/127.0.0.1/tcp/9933/p2p/12D3KooWAAxG7eTEHr2uBVw3BDMxYsxyqfKvj3qqqpRGtTfuzTuH. This will be used for Bob to connect. You can either grab this address from the logs, our you can obtain it with this command:

./swapcli addresses

Pick the localhost address and assign it to a variable. For example (your value will be different):

BOOT_NODE=/ip4/127.0.0.1/tcp/9933/p2p/12D3KooWHRi24PVZ6TBnQJHdVyewDRcKFZtYV3qmB4KQo8iMyqik

Now get the ethereum contract address that Alice deployed to. This can be pulled from the Alice's logs, the file ..., or if you have jq installed (available via sudo apt install jq), you can set a variable like this:

CONTRACT_ADDR=$(jq -r .ContractAddress /tmp/xmrtaker/contract-address.json)

Now start Bob's swapd instance in terminal 2:

./swapd --dev-xmrmaker --bootnodes "${BOOT_NODE}" --contract-address "${CONTRACT_ADDR}"

Note: when using the --dev-xmrtaker and --dev-xmrmaker flags, Alice's RPC server runs on http://localhost:5001 and Bob's runs on http://localhost:5002 by default.

Now, in terminal 3, we will interact with the swap daemon using swapcli.

First we need mine some XMR for Bob. Alice already has ETH, because she is using a prefunded by ganache address. You can see the balances for Bob with the following command:

./swapcli balances --swapd-port 5002

Note that Alice is on the default swapd port of 5001, so the --swapd-port flag is optional when interacting with her daemon.

To mine some monero blocks for Bob, you can use our bash shell function shown below:

source scripts/testlib.sh
mine-monero-for-swapd 5002

Now you can use the second to last command to see Bob's updated monero balance.

Next we need Bob to make an offer and advertise it, so that Alice can take it:

./swapcli make --min-amount 0.1 --max-amount 1 --exchange-rate 0.05 --swapd-port 5002
# Published offer with ID cf4bf01a0775a0d13fa41b14516e4b89034300707a1754e0d99b65f6cb6fffb9

Alternatively, you can make the offer via websockets and get notified when the swap is taken:

./swapcli make --min-amount 0.1 --max-amount 1 --exchange-rate 0.05 --swapd-port 5002 --subscribe

Now, we can have Alice begin discovering peers who have offers advertised.

./swapcli discover --provides XMR --search-time 3
# [[/ip4/127.0.0.1/tcp/9934/p2p/12D3KooWC547RfLcveQi1vBxACjnT6Uv15V11ortDTuxRWuhubGv /ip4/127.0.0.1/tcp/9934/p2p/12D3KooWC547RfLcveQi1vBxACjnT6Uv15V11ortDTuxRWuhubGv]]

Query the returned peer as to how much XMR they can provide and their preferred exchange rate (replace "--multiaddr" field with one of the addresses returned in the above step):

./swapcli query --multiaddr /ip4/192.168.0.101/tcp/9934/p2p/12D3KooWC547RfLcveQi1vBxACjnT6Uv15V11ortDTuxRWuhubGv
# Offer ID=cf4bf01a0775a0d13fa41b14516e4b89034300707a1754e0d99b65f6cb6fffb9 Provides=XMR MinimumAmount=0.1 MaximumAmount=1 ExchangeRate=0.05

Now, we can tell Alice to initiate the protocol w/ the peer (Bob), the offer (copy the Offer id from above), and a desired amount to swap:

./swapcli take --multiaddr /ip4/192.168.0.101/tcp/9934/p2p/12D3KooWC547RfLcveQi1vBxACjnT6Uv15V11ortDTuxRWuhubGv --offer-id cf4bf01a0775a0d13fa41b14516e4b89034300707a1754e0d99b65f6cb6fffb9 --provides-amount 0.05
# Initiated swap with ID=0

Alternatively, you can take the offer via websockets and get notified when the swap status updates:

./swapcli take --multiaddr /ip4/127.0.0.1/tcp/9934/p2p/12D3KooWHLUrLnJtUbaGzTSi6azZavKhNgUZTtSiUZ9Uy12v1eZ7 --offer-id cf4bf01a0775a0d13fa41b14516e4b89034300707a1754e0d99b65f6cb6fffb9 --provides-amount 0.05 --subscribe --swapd-port 5001

If all goes well, you should see Alice and Bob successfully exchange messages and execute the swap protocol. The result is that Alice now owns the private key to a Monero account (and is the only owner of that key) and Bob has the ETH transferred to him. On Alice's side, a Monero wallet will be generated in the --wallet-dir provided in the monero-wallet-rpc step for Alice.

To query the information for an ongoing swap, you can run:

./swapcli get-ongoing-swap

To query information for a past swap using its ID, you can run:

./swapcli get-past-swap --id <id>