8.4 KiB
Eclair (french for Lightning) is a scala implementation of the Lightning Network. It can run with or without a GUI, and a JSON-RPC API is also available.
This software follows the Lightning Network Specifications (BOLTs). Other implementations include lightning-c, lit, and lnd.
🚧 Both the BOLTs and Eclair itself are a work in progress. Expect things to break/change!
⚠️ Eclair currently only runs on regtest or testnet. We recommend testing in regtest, as it allows you to generate blocks manually and not wait for confirmations.
🚨 We had reports of Eclair being tested on various segwit-enabled blockchains. Keep in mind that Eclair is still alpha quality software, by using it with actual coins you are putting your funds at risk!
Lightning Network Specification Compliance
Please see the latest release note for detailed information on BOLT compliance.
Overview
Installation
⚠️ Those are valid for the most up-to-date, unreleased, version of eclair. Here are the instructions for Eclair 0.2-alpha5.
Configuring Bitcoin Core
Eclair needs a synchronized, segwit-ready, zeromq-enabled, non-pruning, tx-indexing Bitcoin Core node. This means that on Windows you will need Bitcoin Core 0.14+.
Run bitcoind with the following minimal bitcoin.conf:
regtest=1
server=1
rpcuser=XXX
rpcpassword=XXX
txindex=1
zmqpubrawblock=tcp://127.0.0.1:29000
zmqpubrawtx=tcp://127.0.0.1:29000
On testnet, you also need to make sure that all your UTXOs are p2sh-of-p2wpkh.
To do this, use the debug console, create a new address with getnewaddress, import it as a witness address with addwitnessaddress, and
send all your balance to this witness address.
If you need to create and send funds manually, don't forget to create and specify a witness address for the change output (this option is avaliable on the GUI once you set the Enable coin control features wallet option).
Installing Eclair
The released binaries can be downloaded here.
Windows
Just use the windows installer, it should create a shortcut on your desktop.
Linux, macOS or manual install on Windows
You need to first install java, more precisely a JRE 1.8.
⚠️ If you are using the OpenJDK JRE, you will need to build OpenJFX yourself, or run the application in headless mode (see below).
Then download the latest fat jar and depending on whether or not you want a GUI run the following command:
- with GUI:
java -jar eclair-node-gui-<version>-<commit_id>.jar
- without GUI:
java -jar eclair-node-<version>-<commit_id>.jar
Configuring Eclair
Configuration file
Eclair reads its configuration file, and write its logs, to ~/.eclair by default.
To change your node's configuration, create a file named eclair.conf in ~/.eclair. Here's an example configuration file:
eclair.server.port=9735
eclair.node-alias=eclair
eclair.node-color=49daaa
Here are some of the most common options:
| name | description | default value |
|---|---|---|
| eclair.server.port | Lightning TCP port | 9735 |
| eclair.api.port | API HTTP port | 8080 |
| eclair.bitcoind.rpcuser | Bitcoin Core RPC user | foo |
| eclair.bitcoind.rpcpassword | Bitcoin Core RPC password | bar |
| eclair.bitcoind.zmq | Bitcoin Core ZMQ address | tcp://127.0.0.1:29000 |
Quotes are not required unless the value contains special characters. Full syntax guide here.
→ see reference.conf for full reference. There are many more options!
Java Environment Variables
Some advanced parameters can be changed with java environment variables. Most users won't need this and can skip this section.
⚠️ Using separate datadir is mandatory if you want to run several instances of eclair on the same machine. You will also have to change ports in eclair.conf (see above).
| name | description | default value |
|---|---|---|
| eclair.datadir | Path to the data directory | ~/.eclair |
| eclair.headless | Run eclair without a GUI | |
| eclair.printToConsole | Log to stdout (in addition to eclair.log) |
For example, to specify a different data directory you would run the following command:
java -Declair.datadir=/tmp/node1 -jar eclair-node-gui-<version>-<commit_id>.jar
JSON-RPC API
| method | params | description |
|---|---|---|
| getinfo | return basic node information (id, chain hash, current block height) | |
| connect | nodeId, host, port | connect to another lightning node through a secure connection |
| open | nodeId, host, port, fundingSatoshis, pushMsat | opens a channel with another lightning node |
| peers | list existing local peers | |
| channels | list existing local channels | |
| channel | channelId | retrieve detailed information about a given channel |
| allnodes | list all known nodes | |
| allchannels | list all known channels | |
| receive | description | generate a payment request without a required amount (can be useful for donations) |
| receive | amountMsat, description | generate a payment request for a given amount |
| send | amountMsat, paymentHash, nodeId | send a payment to a lightning node |
| send | paymentRequest | send a payment to a lightning node using a BOLT11 payment request |
| send | paymentRequest, amountMsat | send a payment to a lightning node using a BOLT11 payment request and a custom amount |
| close | channelId | close a channel |
| close | channelId, scriptPubKey (optional) | close a channel and send the funds to the given scriptPubKey |
| help | display available methods |
Docker
A Dockerfile images are built on each commit on docker hub for running a dockerized eclair-node.
You can use the JAVA_OPTS environment variable to set arguments to eclair-node.
docker run -ti --rm -e "JAVA_OPTS=-Xmx512m -Declair.api.binding-ip=0.0.0.0 -Declair.node-alias=node-pm -Declair.printToConsole" acinq\eclair
If you want to persist the data directory, you can make the volume to your host with the -v argument, as the following example:
docker run -ti --rm -v "/path_on_host:/data" -e "JAVA_OPTS=-Declair.printToConsole" acinq\eclair
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