This software follows the [Lightning Network Specifications (BOLTs)](https://github.com/lightning/bolts).
Other implementations include [core lightning](https://github.com/ElementsProject/lightning), [lnd](https://github.com/LightningNetwork/lnd), [electrum](https://github.com/spesmilo/electrum/), and [ldk](https://github.com/lightningdevkit/rust-lightning).
Eclair relies on Bitcoin Core to interface with and monitor the blockchain and to manage on-chain funds: Eclair does not include an on-chain wallet, channel opening transactions are funded by your Bitcoin Core node, and channel closing transactions return funds to your Bitcoin Core node.
This means that instead of re-implementing them, Eclair benefits from the verifications and optimisations (including fee management with RBF/CPFP, ...) that are implemented by Bitcoin Core. Eclair uses our own [bitcoin library](https://github.com/ACINQ/bitcoin-kmp) to verify data provided by Bitcoin Core.
:warning: This also means that Eclair has strong requirements on how your Bitcoin Core node is configured (see below), and that you must back up your Bitcoin Core wallet as well as your Eclair node (see [here](#configure-bitcoin-core-wallet)):
* You must configure your Bitcoin node to use `bech32` or `bech32m` (segwit) addresses. If your wallet has "non-segwit UTXOs" (outputs that are neither `p2sh-segwit`, `bech32` or `bech32m`), you must send them to a `bech32` or `bech32m` address before running Eclair.
* Eclair requires Bitcoin Core 23.2 or higher. If you are upgrading an existing wallet, you may need to create a new address and send all your funds to that address.
Depending on the actual hardware configuration, it may be useful to provide increased `dbcache` parameter value for faster verification and `rpcworkqueue` parameter value for better handling of API requests on `bitcoind` side.
To run Eclair, you first need to install Java, we recommend that you use [OpenJDK 11](https://adoptopenjdk.net/?variant=openjdk11&jvmVariant=hotspot). Other runtimes also work, but we don't recommend using them.
:warning: Be careful when following tutorials/guides that may be outdated or incomplete. You must thoroughly read the official eclair documentation before running your own node.
Quotes are not required unless the value contains special characters. Full syntax guide [here](https://github.com/lightbend/config/blob/master/HOCON.md).
Eclair will use the default loaded Bitcoin Core wallet to fund any channels you choose to open.
If you want to use a different wallet from the default one, you must set `eclair.bitcoind.wallet` accordingly in your `eclair.conf`.
:warning: Once a wallet is configured, you must be very careful if you want to change it: changing the wallet when you have channels open may result in a loss of funds (or a complex recovery procedure).
Eclair will return BTC from closed channels to the wallet configured.
Any BTC found in the wallet can be used to fund the channels you choose to open.
We also recommend tweaking the following parameters in `bitcoin.conf`:
```conf
# This parameter ensures that your wallet will not create chains of unconfirmed
# transactions that would be rejected by other nodes.
walletrejectlongchains=1
# The following parameters set the maximum length of chains of unconfirmed
# transactions to 20 instead of the default value of 25.
limitancestorcount=20
limitdescendantcount=20
```
Setting these parameters lets you unblock long chains of unconfirmed channel funding transactions by using child-pays-for-parent (CPFP) to make them confirm.
With the default `bitcoind` parameters, if your node created a chain of 25 unconfirmed funding transactions with a low-feerate, you wouldn't be able to use CPFP to raise their fees because your CPFP transaction would likely be rejected by the rest of the network.
: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 uses [`logback`](https://logback.qos.ch) for logging. To use a [different configuration](./docs/Logging.md), and override the internal logback.xml, run:
For Bitcoin Core, you need to backup the wallet file for the wallet that Eclair is using. You only need to do this once, when the wallet is
created. See [Managing Wallets](https://github.com/bitcoin/bitcoin/blob/master/doc/managing-wallets.md) in the Bitcoin Core documentation for more information.
For example, you could configure a `cron` task for your backup job. Or you could configure an optional notification script to be called by eclair once a new database snapshot has been created, using the following option:
A [Dockerfile](Dockerfile) x86_64 image is built on each commit on [docker hub](https://hub.docker.com/r/acinq/eclair) for running a dockerized eclair-node.
A valid plugin is a jar that contains an implementation of the [Plugin](eclair-node/src/main/scala/fr/acinq/eclair/Plugin.scala) interface, and a manifest entry for `Main-Class` with the FQDN of the implementation.
