Struct AnchorChannelsConfig

pub struct AnchorChannelsConfig {
    pub trusted_peers_no_reserve: Vec<PublicKey>,
    pub per_channel_reserve_sats: u64,
}

Configuration options pertaining to ‘Anchor’ channels, i.e., channels for which the option_anchors_zero_fee_htlc_tx channel type is negotiated.

Prior to the introduction of Anchor channels, the on-chain fees paying for the transactions issued on channel closure were pre-determined and locked-in at the time of the channel opening. This required to estimate what fee rate would be sufficient to still have the closing transactions be spendable on-chain (i.e., not be considered dust). This legacy design of pre-anchor channels proved inadequate in the unpredictable, often turbulent, fee markets we experience today.

In contrast, Anchor channels allow to determine an adequate fee rate at the time of channel closure, making them much more robust in the face of fee spikes. In turn, they require to maintain a reserve of on-chain funds to have the channel closure transactions confirmed on-chain, at least if the channel counterparty can’t be trusted to do this for us.

See BOLT 3 for more technical details on Anchor channels.

Defaults

Parameter	Value
trusted_peers_no_reserve	[]
per_channel_reserve_sats	25000

Fields

trusted_peers_no_reserve: Vec<PublicKey>

A list of peers that we trust to get the required channel closing transactions confirmed on-chain.

Channels with these peers won’t count towards the retained on-chain reserve and we won’t take any action to get the required channel closing transactions confirmed ourselves.

Note: Trusting the channel counterparty to take the necessary actions to get the required Anchor spending transactions confirmed on-chain is potentially insecure as the channel may not be closed if they refuse to do so.

per_channel_reserve_sats: u64

The amount of satoshis per anchors-negotiated channel with an untrusted peer that we keep as an emergency reserve in our on-chain wallet.

This allows for having the required Anchor output spending and HTLC transactions confirmed when the channel is closed.

If the channel peer is not marked as trusted via AnchorChannelsConfig::trusted_peers_no_reserve, we will always try to spend the Anchor outputs with any on-chain funds available, i.e., the total reserve value as well as any spendable funds available in the on-chain wallet. Therefore, this per-channel multiplier is really a emergency reserve that we maintain at all time to reduce reduce the risk of insufficient funds at time of a channel closure. To this end, we will refuse to open outbound or accept inbound channels if we don’t have sufficient on-chain funds available to cover the additional reserve requirement.

Note: Depending on the fee market at the time of closure, this reserve amount might or might not suffice to successfully spend the Anchor output and have the HTLC transactions confirmed on-chain, i.e., you may want to adjust this value accordingly.

Trait Implementations

impl Clone for AnchorChannelsConfig

fn clone(&self) -> AnchorChannelsConfig

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for AnchorChannelsConfig

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for AnchorChannelsConfig

fn default() -> Self

Returns the “default value” for a type.