sample

rust-dlc sample

Example of combining the various components of the rust-dlc library together with the custom message handler of rust-lightning to enable networked communication.

Originally based on the code from the ldk sample.

Example configurations and contract input are available in the examples folder. In order to use the example contract you will need to update the event_id. Replace the part after btcusd with a UNIX timestamp in the future.

Use the helper script to create the example contract 1 hour in the future. This will duplicate the numerical_contract_input.json sample under the name sample_contract.json, and modify the event_id with a UNIX timestamp 1 hour in the future. Manually update the value for a longer time period.

Quick run

To give a quick try to this sample, run the following set of commands (assuming that the working directory is the one in which this readme is located and that docker (and docker-compose, for V1; V2 is part of docker) is available on your machine):

docker compose --profile oracle up -d
docker compose exec bitcoind /scripts/create_wallets.sh
cargo run ./examples/configurations/alice.yml

In a different terminal:

cargo run ./examples/configurations/bob.yml

On chain DLC

From the second instance (Bob), type:

offercontract 02c84f8e151590e718d22e528c55f14c0042c66e68c3f793d7b3b8bf5ae630c648@127.0.0.1:9000 ./examples/contracts/sample_contract.json

Replacing the public key by the one that was displayed when starting the first instance.

From the first instance (Alice), type:

listoffers

You should see the id of the contract that was offered by Bob. A JSON file with contract information should also have been saved in Alice's data folder (./dlc_sample_alice/offers/xxx.json). Note: Just pressing Enter will also trigger checking and handling of pending messages.

Alice can now accept the offer by typing:

acceptoffer xxxxx

replacing xxxxx with the contract id that was previously displayed.

This will make Alice's instance send an accept message to Bob. In Bob's instance, typing listcontracts will trigger the processing of the message, and you should see that the contract will be in Signed, as Bob will automatically reply to Alice with a Sign message.

Typing the same command in Alice's instance will make Alice broadcast the fund transaction.

Now in yet another terminal (still from the same location) run:

docker compose exec bitcoind /scripts/generate_blocks.sh

This will generate some blocks so that the fund transaction is confirmed.

Typing listcontracts in either instance should now show the contract as Confirmed.

Once the maturity of the contract is reached, typing listcontracts once more will retrieve the attestation from the oracle and close the contract, displaying the event outcome (in decomposed binary format) and the profit and loss for the given instance.

DLC channels

From the second instance (Bob), type:

offerchannel 02c84f8e151590e718d22e528c55f14c0042c66e68c3f793d7b3b8bf5ae630c648@127.0.0.1:9000 ./examples/contracts/sample_contract.json

Replacing the public key by the one that was displayed when starting the first instance.

From the first instance (Alice), type:

listchanneloffers

You should see the id of the contract that was offered by Bob. A JSON file with contract information should also have been saved in Alice's data folder (./dlc_sample_alice/offers/xxx.json).

Alice can now accept the offer by typing:

acceptchannel xxxxx

replacing xxxxx with the channel id that was previously displayed.

This will make Alice's instance send an accept message to Bob. In Bob's instance, typing listsignedchannels will trigger the processing of the message, and you should see that the channel id being displayed (different than the one during the offer as it was a temporary id previously).

Typing the same command in Alice's instance will make Alice broadcast the fund transaction.

Now in yet another terminal (still from the same location) run:

docker compose exec bitcoind /scripts/generate_blocks.sh

This will generate some blocks so that the fund transaction is confirmed. The channel is now setup.

Settle the contract in the channel

One of the party can offer a settlement of the contract within the channel. To do so, use the offersettlechannel command, passing in the channel id (that you can get using the listsignedchannels command), as well as the proposed payout for the counter party.

In the other terminal, use the listsettlechanneloffers to display the received settle offer.

To accept the offer, use the acceptsettlechanneloffer passing the channel id as a parameter. Three messages need to be exchanged between the peers to properly settle the channel, press Enter once in the terminal where the settle offer was made, once where the settle offer was received and once more where the settle offer was made for the settlement to be finalized.

To reject the offer, use the rejectsettlechanneloffer command, passing the channel id as a parameter.

Renew the contract in the channel

One of the party can offer to renew the contract in the channel. To do so, use the offerchannelrenew command, passing in the channel id (that you can get using the listsignedchannels command), the proposed payout for the counter party, and the path to the json file containing the information about the contract to offer.

In the other terminal, use the listrenewchanneloffers to display the received settle offer.

To accept the offer, use the acceptrenewchanneloffer passing the channel id as a parameter. Three messages need to be exchanged between the peers to properly settle the channel, press Enter once in the terminal where the settle offer was made, once where the settle offer was received and once more where the settle offer was made for the settlement to be finalized.

To reject the offer, use the rejectrenewchanneloffer command, passing the channel id as a parameter.