eclair

A scala implementation of the Lightning Network. Eclair is french for Lightning.

This software follows the BOLT specifications, therefore it is compatible with Blockstream's lightning-c.

Overview

The general idea is to have an actor per channel, everything being non-blocking.

A "blockchain watcher" is responsible for monitoring the blockchain, and sending events (eg. when the anchor is spent).

Modules

• lightning-types: scala code generation using protobuf's compiler (wire protocol)
• eclair-demo: actual implementation

Usage

Prerequisites:

• A JRE or JDK depending on wether you want to compile yourself or not (preferably > 1.8)
• A running bitcoin-demo (testnet or regtest)

⚠️ eclair currently runs on segnet only. Do not try and modify it to run on bitcoin mainnet!

Either run from source:

mvn exec:java -Dexec.mainClass=fr.acinq.eclair.Boot

Or grab the latest released jar and run:

java -jar eclair-demo_2.11-*-capsule-fat.jar

See TESTING.md for more details on how to use this software.

Available jvm options (see application.conf for full reference):

eclair.server.port (default: 45000)
eclair.http.port (default: 8080)
eclair.bitcoind.rpcuser (default: foo)
eclair.bitcoind.rpcpassword (default: bar)

JSON-RPC API

method	params	description
connect	host, port, anchor_amount	opens a channel with another eclair or lightningd instance
list		lists existing channels
addhtlc	channel_id, amount, rhash, locktime	sends an htlc
fulfillhtlc	channel_id, r	fulfills an htlc
close	channel_id	closes a channel
help		displays available methods

Status

• Network
• Routing
• Channel protocol
• HTLC Scripts
• Unilateral close handling
• Relaying Payment
• Fee management
• Blockchain watcher
• Storing states in a database

Resources

• [1] The Bitcoin Lightning Network: Scalable Off-Chain Instant Payments by Joseph Poon and Thaddeus Dryja
• [2] Reaching The Ground With Lightning by Rusty Russell

Other implementations

Name	Language	Compatible
Amiko-Pay	Python	no
lightning-c	C	yes
lnd	Go	no
Thunder	Java	no