webcash twinkle

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Automated sats for webcash micro swap.

Webcash twinkle allows 2 parties to trade sats for webcash by communicating and exchanging over a lightning channel. The script will ask both parties for the amounts and # of trade lots, and start to automatically swap. Sellers need to ensure they have enough wallet balance and buyers need to ensure they have enough local channel capacity to send sats.

The webcash seller settles first.

The python script uses gRPC for communication with the Lightning Network Daemon.

Disclaimer

Review the code and use at your sole risk. Webcash terms of service apply.

Installation

Ensure you have lnd installed with key-send capability (set in ~/.lnd/lnd.conf) by adding accept-keysend=true.
In case you don't have a full bitcoin node backend, you can still run lnd in neutrino mode, which requires minimal diskspace. Set the --bitcoin.node flag to neutrino, point the --neutrino.addpeer flag to faucet.lightning.community and grab the fees from https://nodes.lightning.computer/fees/v1/btc-fee-estimates.json using the --fee-url flag.

For example:
```
lnd --bitcoin.active --bitcoin.mainnet --bitcoin.node=neutrino --neutrino.addpeer=faucet.lightning.community --feeurl https://nodes.lightning.computer/fees/v1/btc-fee-estimates.json
```
Compile and install the gRPC dependencies (googleapis): lnd lightning.proto and RPC modules for subservers. These are 4 files called lightning_pb2_grpc.py, lightning_pb2.py, router_pb2_grpc.py, router_pb2.py.

These dependencies allow us to use lnd via python, keep them in the same working directory. Visit the official repository for detailed instructions on how to generate them.
Download the customised webcash library and keep it in your webcash twinkle folder.

Please note: The official webcash library will not work as its intended to be run from the cli. The modified webcash library makes small changes to pass status and token secrets back to the twinkle script.

Usage

The buyer opens a lightning channel with the seller using lncli with the necessary capacity (remember to enable keysend)
The webcash seller loads a local webcash wallet
Both parties enter the corresponding side's pubkey and their desired trade parameters
webcash twinkle will cross-check to ensure both parties are 100% in agreement, and then start to piecemeal the transaction. Errors or cheating attempts will cause the script to terminate

It's recommended prior to starting the script to see if you can push 1 sat accross the channel using lncli --keysend. This will help ensure your setup is good and aid any troubleshooting.

Bugs

Please report any.

License