perun-network/perun-eth-payment

Perun Ethereum Payment Client

This project provides a simplified interface to the go-perun framework. It enables developers to get started quickly with go-perun by using a condensed API.
If you just want to create a go-perun payment application on Ethereum, this is for you.

Security Disclaimer

Do not use this software with real funds.

go-perun is still in development. The authors take no responsibility for any loss of digital assets or other damage caused by the use of this software.

Primer

You can import perun-eth-payment as go module:

import "github.com/perun-network/perun-eth-payment"

Here is an example with the most important functions.
It sets up the framework, opens a channel to Bob, sends him 0.5 ETH, waits for a return payment and shuts down.

package main

import (
    "context"
    "fmt"
    "math/big"
    "time"

    "github.com/ethereum/go-ethereum/common"
    ethwallet "perun.network/go-perun/backend/ethereum/wallet"
    payment "github.com/perun-network/perun-eth-payment"
)

func main() {
    // Initialize mnemonic wallet
    wallet, err := payment.NewWalletHD(big.NewInt(5), "your mnemonic", 1)
    if err != nil { /* handle error */ }

    // Setup config struct and client
    config := payment.MakeConfig("127.0.0.1:6444", "ws://127.0.0.1:8454", 60 * time.Second)
    client, err := payment.NewClient(wallet, config)
    if err != nil { /* handle error */ }
    // Long context that will be used from now on
    ctx, cancel := context.WithTimeout(context.Background(), 10 * time.Minute)
    defer cancel()

    // Set the contract addresses of the Adjudicator and Assetholder
    client.Init(ctx, common.HexToAddress("0x20e1D1642284AdB74520f0e91835bbc6d5ec3415"),
                     common.HexToAddress("0x3f6629d37E84E6Da88978198c9A1B228C5722085"))

    // Register the peer that we want to open a channel with.
    bobAddr := ethwallet.AsWalletAddr(common.HexToAddress("0xB5d05705c467bfEd944B6769A689c7766CC1f805"))
    bob, err := client.RegisterPeer(bobAddr, "192.168.2.100:6444", "Bob")
    if err != nil { /* handle error */ }

    // Set the initial balance for the channel and open it.
    initBals := payment.MakeBals(payment.MakeAmountFromETH(1), payment.MakeAmountFromETH(1))
    channel, err := client.ProposeChannel(ctx, bob, initBals)
    if err != nil { /* handle error */ }

    // Send 0.5 ETH to Bob
    err = channel.Send(ctx, payment.MakeAmountFromETH(0.5))
    if err != nil { /* handle error */ }
    // Wait for Bob to send us something back
    received := <-channel.Received()
    fmt.Printf("Received %v ETH from Bob", received.ETH())

    // Close the channel and client at the end
    err = channel.Close(ctx)
    if err != nil { /* handle error */ }
    err = client.Close(ctx)
    if err != nil { /* handle error */ }
}

Architecture

The following UML diagram shows the complete interface in abbreviated form:

Copyright

Copyright 2021 PolyCrypt GmbH
Use of the source code is governed by the Apache 2.0 license that can be found in the LICENSE file.