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.
:construction: Both the BOLTs and Eclair itself are still a work in progress. Expect things to break/change!
:rotating_light: If you intend to run Eclair on mainnet:
- Keep in mind that it is beta-quality software and don't put too much money in it
- Eclair's JSON-RPC API should NOT be accessible from the outside world (similarly to Bitcoin Core API)
- Specific configuration instructions for mainnet are provided below (by default Eclair runs on testnet)
Lightning Network Specification Compliance
Please see the latest release note for detailed information on BOLT compliance.
Configuring Bitcoin Core
:warning: Eclair requires Bitcoin Core 0.16.0 or higher. If you are upgrading an existing wallet, you need to create a new address and send all your funds to that address.
Eclair needs a synchronized, segwit-ready, zeromq-enabled, wallet-enabled, non-pruning, tx-indexing Bitcoin Core node.
Eclair will use any BTC it finds in the Bitcoin Core wallet to fund any channels you choose to open. Eclair will return BTC from closed channels to this wallet.
Run bitcoind with the following minimal
testnet=1 server=1 rpcuser=foo rpcpassword=bar txindex=1 zmqpubrawblock=tcp://127.0.0.1:29000 zmqpubrawtx=tcp://127.0.0.1:29000 addresstype=p2sh-segwit
The released binaries can be downloaded here.
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.
:warning: 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
Eclair reads its configuration file, and write its logs, to
~/.eclair by default.
To change your node's configuration, create a file named
~/.eclair. Here's an example configuration file:
eclair.chain=testnet eclair.node-alias=eclair eclair.node-color=49daaa
Here are some of the most common options:
|eclair.chain||Which blockchain to use: regtest, testnet or mainnet||testnet|
|eclair.server.port||Lightning TCP port||9735|
|eclair.api.enabled||Enable/disable the API||false. By default the API is disabled. If you want to enable it, you must set a password.|
|eclair.api.port||API HTTP port||8080|
|eclair.api.password||API password (BASIC)||"" (must be set if the API is enabled)|
|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"|
|eclair.gui.unit||Unit in which amounts are displayed (possible values: msat, sat, mbtc, btc)||btc|
Quotes are not required unless the value contains special characters. Full syntax guide here.
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.
:warning: 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).
|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
|getinfo||return basic node information (id, chain hash, current block height)|
|connect||nodeId, host, port||open a secure connection to a lightning node|
|connect||uri||open a secure connection to a lightning node|
|open||nodeId, fundingSatoshis, pushMsat = 0, feerateSatPerByte = ?, channelFlags = 0x01||open a channel with another lightning node, by default push = 0, feerate for the funding tx targets 6 blocks, and channel is announced|
|peers||list existing local peers|
|channels||list existing local channels|
|channels||nodeId||list existing local channels opened with a particular nodeId|
|channel||channelId||retrieve detailed information about a given channel|
|allnodes||list all known nodes|
|allchannels||list all known channels|
|allupdates||list all channels updates|
|allupdates||nodeId||list all channels updates for this nodeId|
|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|
|checkinvoice||paymentRequest||returns node, amount and payment hash in an invoice/paymentRequest|
|findroute||paymentRequest||nodeId||given a payment request or nodeID checks if there is a valid payment route returns JSON with attempts, nodes and channels of route|
|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|
|checkpayment||paymentHash||returns true if the payment has been received, false otherwise|
|checkpayment||paymentRequest||returns true if the payment has been received, false otherwise|
|close||channelId||close a channel|
|close||channelId, scriptPubKey||close a channel and send the funds to the given scriptPubKey|
|forceclose||channelId||force-close a channel by publishing the local commitment tx (careful: this is more expensive than a regular close and will incur a delay before funds are spendable)"|
|help||display available methods|
You can use the
JAVA_OPTS environment variable to set arguments to
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
Following are the minimum configuration files you need to use for Bitcoin Core and Eclair.
Bitcoin Core configuration
testnet=0 server=1 rpcuser=<your-rpc-user-here> rpcpassword=<your-rpc-password-here> txindex=1 zmqpubrawblock=tcp://127.0.0.1:29000 zmqpubrawtx=tcp://127.0.0.1:29000 addresstype=p2sh-segwit
eclair.chain=mainnet eclair.bitcoind.rpcport=8332 eclair.bitcoind.rpcuser=<your-bitcoin-core-rpc-user-here> eclair.bitcoind.rpcpassword=<your-bitcoin-core-rpc-passsword-here>
-  The Bitcoin Lightning Network: Scalable Off-Chain Instant Payments by Joseph Poon and Thaddeus Dryja
-  Reaching The Ground With Lightning by Rusty Russell
-  Lightning Network Explorer - Explore testnet LN nodes you can connect to