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 c-lightning and lnd.
🚧 Both the BOLTs and Eclair itself are still a work in progress. Expect things to break/change!
🚨 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)
Please see the latest release note for detailed information on BOLT compliance.
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 bitcoin.conf:
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.
You need to first install java, more precisely a JRE 1.8.
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>.jarEclair 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.chain=testnet
eclair.node-alias=eclair
eclair.node-color=49daaa
Here are some of the most common options:
| name | description | default value |
|---|---|---|
| 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.
→ see reference.conf for full reference. There are many more options!
Some advanced parameters can be changed with java environment variables. Most users won't need this and can skip this section.
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| method | params | description |
|---|---|---|
| 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 |
| updaterelayfee | channelId, feeBaseMsat, feeProportionalMillionths | updates the outgoing fee on this channel |
| 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 |
| receive | amountMsat, description, expirySeconds | generate a payment request for a given amount that expires after given number of seconds |
| checkinvoice | paymentRequest | returns node, amount and payment hash in an invoice/paymentRequest |
| findroute | paymentRequest | nodeId |
| 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 |
A Dockerfile image is 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
Following are the minimum configuration files you need to use for Bitcoin Core and Eclair.
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>
- [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
- [3] Lightning Network Explorer - Explore testnet LN nodes you can connect to