# Eclair vnext ## Major changes ### Add support for channel aliases and zeroconf channels :information_source: Those features are only supported for channels of type `AnchorOutputsZeroFeeHtlcTx`, which is the newest channel type and the one enabled by default. If you are opening a channel with a node that doesn't run Eclair, make sure they support `option_anchors_zero_fee_htlc_tx`. #### Channel aliases Channel aliases offer a way to use arbitrary channel identifiers for routing. This feature improves privacy by not leaking the funding transaction of the channel during payments. This feature is enabled by default, but your peer has to support it too, and it is not compatible with public channels. #### Zeroconf channels Zeroconf channels make it possible to use a newly created channel before the funding tx is confirmed on the blockchain. :warning: Zeroconf requires the fundee to trust the funder. For this reason it is disabled by default, and you can only enable it on a peer-by-peer basis. ##### Enabling through features Below is how to enable zeroconf with a given peer in `eclair.conf`. With this config, your node will _accept_ zeroconf channels from node `03864e...`. ```eclair.conf override-init-features = [ { nodeid = "03864ef025fde8fb587d989186ce6a4a186895ee44a926bfc370e2c366597a3f8f", features = { // dependencies of zeroconf option_static_remotekey = optional option_anchors_zero_fee_htlc_tx = optional option_scid_alias = optional // enable zeroconf option_zeroconf = optional } } ] ``` Note that, as funder, Eclair will happily use an unconfirmed channel if the peer sends an early `channel_ready`, even if the `option_zeroconf` feature isn't enabled, as long as the peer provides a channel alias. ##### Enabling through channel type You can enable `option_scid_alias` and `option_zeroconf` features by requesting them in the channel type, even if those options aren't enabled in your features. The new channel types variations are: - `anchor_outputs_zero_fee_htlc_tx+scid_alias` - `anchor_outputs_zero_fee_htlc_tx+zeroconf` - `anchor_outputs_zero_fee_htlc_tx+scid_alias+zeroconf` Examples using the command-line interface: - open a public zeroconf channel: ```shell $ ./eclair-cli open --nodeId=03864e... --fundingSatoshis=100000 --channelType=anchor_outputs_zero_fee_htlc_tx+zeroconf --announceChannel=true ``` - open a private zeroconf channel with aliases: ```shell $ ./eclair-cli open --nodeId=03864e... --fundingSatoshis=100000 --channelType=anchor_outputs_zero_fee_htlc_tx+scid_alias+zeroconf --announceChannel=false ``` ### Experimental support for dual-funding This release adds experimental support for dual-funded channels, as specified [here](https://github.com/lightning/bolts/pull/851). Dual-funded channels have many benefits: - both peers can contribute to channel funding - the funding transaction can be RBF-ed This feature is turned off by default, because there may still be breaking changes in the specification. To turn it on, simply enable the feature in your `eclair.conf`: ```conf eclair.features.option_dual_fund = optional ``` If your peer also supports the feature, eclair will automatically use dual-funding when opening a channel. If the channel doesn't confirm, you can use the `rbfopen` RPC to initiate an RBF attempt and speed up confirmation. In this first version, the non-initiator cannot yet contribute funds to the channel. This will be added in future updates. ### Changes to features override Eclair supports overriding features on a per-peer basis, using the `eclair.override-init-features` field in `eclair.conf`. These overrides will now be applied on top of the default features, whereas the previous behavior was to completely ignore default features. We provide detailed examples in the [documentation](../Configure.md#customize-features). ### Remove support for Tor v2 Dropped support for version 2 of Tor protocol. That means: - Eclair can't open control connection to Tor daemon version 0.3.3.5 and earlier anymore - Eclair can't create hidden services for Tor protocol v2 with newer versions of Tor daemon IMPORTANT: You'll need to upgrade your Tor daemon if for some reason you still use Tor v0.3.3.5 or earlier before upgrading to this release. ### API changes - `channelbalances` retrieves information about the balances of all local channels (#2196) - `channelbalances` and `usablebalances` return a `shortIds` object instead of a single `shortChannelId` (#2323) - `stop` stops eclair: please note that the recommended way of stopping eclair is simply to kill its process (#2233) - `rbfopen` lets the initiator of a dual-funded channel RBF the funding transaction (#2275) ### Miscellaneous improvements and bug fixes #### Delay enforcement of new channel fees When updating the relay fees for a channel, eclair can now continue accepting to relay payments using the old fee even if they would be rejected with the new fee. By default, eclair will still accept the old fee for 10 minutes, you can change it by setting `eclair.relay.fees.enforcement-delay` to a different value. If you want a specific fee update to ignore this delay, you can update the fee twice to make eclair forget about the previous fee. #### New minimum funding setting for private channels New settings have been added to independently control the minimum funding required to open public and private channels to your node. The `eclair.channel.min-funding-satoshis` setting has been deprecated and replaced with the following two new settings and defaults: - `eclair.channel.min-public-funding-satoshis = 100000` - `eclair.channel.min-private-funding-satoshis = 100000` If your configuration file changes `eclair.channel.min-funding-satoshis` then you should replace it with both of these new settings. #### Expired incoming invoices now purged if unpaid Expired incoming invoices that are unpaid will be searched for and purged from the database when Eclair starts up. Thereafter searches for expired unpaid invoices to purge will run once every 24 hours. You can disable this feature, or change the search interval with two new settings: - `eclair.purge-expired-invoices.enabled = true - `eclair.purge-expired-invoices.interval = 24 hours` #### Skip anchor CPFP for empty commitment When using anchor outputs and a channel force-closes without HTLCs in the commitment transaction, funds cannot be stolen by your counterparty. In that case eclair can skip spending the anchor output to save on-chain fees, even if the transaction doesn't confirm. This can be activated by setting the following value in your `eclair.conf`: ```conf eclair.on-chain-fees.spend-anchor-without-htlcs = false ``` This is disabled by default, because there is still a risk of losing funds until bitcoin adds support for package relay. If the mempool becomes congested and the feerate is too low, the commitment transaction may never reach miners' mempools because it's below the minimum relay feerate. #### Public IP addresses can be DNS host names You can now specify a DNS host name as one of your `server.public-ips` addresses (see PR [#911](https://github.com/lightning/bolts/pull/911)). Note: you can not specify more than one DNS host name. #### Support for testing on the signet network To test Eclair with bitcoind configured for signet, set the following values in `eclair.conf`: ```conf eclair.chain = "signet" eclair.bitcoind.rpcport=38332 ``` ## Verifying signatures You will need `gpg` and our release signing key 7A73FE77DE2C4027. Note that you can get it: - from our website: https://acinq.co/pgp/drouinf.asc - from github user @sstone, a committer on eclair: https://api.github.com/users/sstone/gpg_keys To import our signing key: ```sh $ gpg --import drouinf.asc ``` To verify the release file checksums and signatures: ```sh $ gpg -d SHA256SUMS.asc > SHA256SUMS.stripped $ sha256sum -c SHA256SUMS.stripped ``` ## Building Eclair builds are deterministic. To reproduce our builds, please use the following environment (*): - Ubuntu 20.04 - AdoptOpenJDK 11.0.6 - Maven 3.8.1 Use the following command to generate the eclair-node package: ```sh mvn clean install -DskipTests ``` That should generate `eclair-node/target/eclair-node--XXXXXXX-bin.zip` with sha256 checksums that match the one we provide and sign in `SHA256SUMS.asc` (*) You may be able to build the exact same artefacts with other operating systems or versions of JDK 11, we have not tried everything. ## Upgrading This release is fully compatible with previous eclair versions. You don't need to close your channels, just stop eclair, upgrade and restart. ## Changelog