lightning-multifundchannel -- Command for establishing many lightning channels

SYNOPSIS

multifundchannel destinations [feerate] [minconf] [utxos] [minchannels] [commitment_feerate]

DESCRIPTION

The multifundchannel RPC command opens multiple payment channels with nodes by committing a single funding transaction to the blockchain that is shared by all channels.

If not already connected, multifundchannel will automatically attempt to connect; you may provide a @host:port hint appended to the node ID so that Core Lightning can learn how to connect to the node; see lightning-connect(7).

Once the transaction is confirmed, normal channel operations may begin. Readiness is indicated by listpeers reporting a state of CHANNELD_NORMAL for the channel.

destinations (array of objects): There must be at least one entry in destinations; it cannot be an empty array.:
- id (string): Node ID, with an optional @host:port appended to it in a manner understood by connect; see lightning-connect(7). Each entry in the destinations array must have a unique node id. If not already connected, multifundchannel will automatically attempt to connect to the node.
- amount (sat_or_all): Amount in satoshis taken from the internal wallet to fund the channel (but if we have any anchor channels, this will always leave at least min-emergency-msat as change). The string all can be used to specify all available funds (or 16,777,215 satoshi if more is available and large channels were not negotiated with the peer). Otherwise it is in satoshi precision; it can be a whole number, a whole number ending in sat, a whole number ending in 000msat, or a number with 1 to 8 decimal places ending in btc. The value cannot be less than the dust limit, currently 546 satoshi as of this writing, nor more than 16,777,215 satoshi (unless large channels were negotiated with the peer).
- announce (boolean, optional): Flag that indicates whether to announce the channel with this. If set to False, the channel is unpublished. The default is True.
- push_msat (msat, optional): Amount of millisatoshis to outright give to the node. This is a gift to the peer, and you do not get a proof-of-payment out of this.
- close_to (string, optional): Bitcoin address to which the channel funds should be sent to on close. Only valid if both peers have negotiated option_upfront_shutdown_script Returns close_to set to closing script iff is negotiated.
- request_amt (sat, optional): Amount of liquidity you'd like to lease from peer. If peer supports option_will_fund, indicates to them to include this much liquidity into the channel. Must also pass in compact_lease.
- compact_lease (string, optional): Compact representation of the peer's expected channel lease terms. If the peer's terms don't match this set, we will fail to open the channel to this destination.
- mindepth (u32, optional): Number of confirmations before we consider the channel active.
- reserve (sat, optional): Amount we want the peer to maintain on its side of the channel. It can be a whole number, a whole number ending in sat, a whole number ending in 000msat, or a number with 1 to 8 decimal places ending in btc. The default is 1% of the funding amount.
feerate (feerate, optional): Feerate used for the opening transaction, and if commitment_feerate is not set, as initial feerate for commitment and HTLC transactions. See NOTES in lightning-feerates(7) for possible values. The default is normal.
minconf (integer, optional): Minimum number of confirmations that used outputs should have. The default is 1.
utxos (array of outpoints, optional):
- (outpoint, optional): Utxos to be used to fund the channel, as an array of txid:vout.
minchannels (integer, optional): Re-attempt funding as long as at least this many peers remain (must not be zero). The multifundchannel command will only fail if too many peers fail the funding process.
commitment_feerate (feerate, optional): Initial feerate for commitment and HTLC transactions. See feerate for valid values.

RETURN VALUE

This command opens multiple channels with a single large transaction, thus only one transaction is returned.

If minchannels was specified and is less than the number of destinations, then it is possible that one or more of the destinations do not have a channel even if multifundchannel succeeded.
On success, an object is returned, containing:

tx (hex): The raw transaction which funded the channel.
txid (txid): The txid of the transaction which funded the channel.
channel_ids (array of objects):
- id (pubkey): The peer we opened the channel with.
- outnum (u32): The 0-based output index showing which output funded the channel.
- channel_id (hash): The channel_id of the resulting channel.
- channel_type (object): Channel_type as negotiated with peer. (added v24.02):
  - bits (array of u32s): Each bit set in this channel_type. (added v24.02):
    - (u32, optional): Bit number.
  - names (array of strings): Feature name for each bit set in this channel_type. Note that anchors_zero_fee_htlc_tx is a deprecated synonym for anchors. (added v24.02):
    - (string, optional) (one of "static_remotekey/even", "anchor_outputs/even", "anchors_zero_fee_htlc_tx/even", "anchors/even", "scid_alias/even", "zeroconf/even"): Name of feature bit.
- close_to (hex, optional): The raw scriptPubkey which mutual close will go to; only present if close_to parameter was specified and peer supports option_upfront_shutdown_script.
failed (array of objects, optional): Any peers we failed to open with (if minchannels was specified less than the number of destinations).:
- id (pubkey): The peer we failed to open the channel with.
- method (string) (one of "connect", "openchannel_init", "fundchannel_start", "fundchannel_complete"): What stage we failed at.
- error (object):
  - code (integer): JSON error code from failing stage.
  - message (string): Message from stage.
  - data: Additional error data.

On failure, none of the channels are created.

ERRORS

The following error codes may occur:

-1: Catchall nonspecific error.
300: The maximum allowed funding amount is exceeded.
301: There are not enough funds in the internal wallet (including fees) to create the transaction.
302: The output amount is too small, and would be considered dust.
303: Broadcasting of the funding transaction failed, the internal call to bitcoin-cli returned with an error.
313: The min-emergency-msat reserve not be preserved (and we have or are opening anchor channels).

Failure may also occur if lightningd and the peer cannot agree on channel parameters (funding limits, channel reserves, fees, etc.). See lightning-fundchannel_start(7) and lightning-fundchannel_complete(7).

There may be rare edge cases where a communications failure later in the channel funding process will cancel the funding locally, but the peer thinks the channel is already waiting for funding lockin. In that case, the next time we connect to the peer, our node will tell the peer to forget the channel, but some nodes (in particular, Core Lightning nodes) will disconnect when our node tells them to forget the channel. If you immediately multifundchannel with that peer, it could trigger this connect-forget-disconnect behavior, causing the second multifundchannel to fail as well due to disconnection. Doing a connect with the peers separately, and waiting for a few seconds, should help clear this hurdle; running multifundchannel a third time would also clear this.

AUTHOR

ZmnSCPxj <[email protected]> is mainly responsible.

RESOURCES

Main web site: https://github.com/ElementsProject/lightning

EXAMPLES

Example 1: This example opens three channels at once, with amounts 20,000 sats, 30,000 sats
and the final channel using all remaining funds (actually, capped at 16,777,215 sats
because large-channels is not enabled):

Request:

lightning-cli multifundchannel -k "destinations"='[{"id": "nodeid030303030303030303030303030303030303030303030303030303030303@127.0.0.1:19736", "amount": "20000sat"}, {"id": "nodeid040404040404040404040404040404040404040404040404040404040404@127.0.0.1:19737", "amount": "0.0003btc"}, {"id": "nodeid050505050505050505050505050505050505050505050505050505050505@127.0.0.1:19738", "amount": "all"}]' "feerate"="10000perkw" "commitment_feerate"="2000perkw"

{
  "id": "example:multifundchannel#1",
  "method": "multifundchannel",
  "params": {
    "destinations": [
      {
        "id": "nodeid030303030303030303030303030303030303030303030303030303030303@127.0.0.1:19736",
        "amount": "20000sat"
      },
      {
        "id": "nodeid040404040404040404040404040404040404040404040404040404040404@127.0.0.1:19737",
        "amount": "0.0003btc"
      },
      {
        "id": "nodeid050505050505050505050505050505050505050505050505050505050505@127.0.0.1:19738",
        "amount": "all"
      }
    ],
    "feerate": "10000perkw",
    "commitment_feerate": "2000perkw"
  }
}

Response:

{
  "tx": "02000000000101multif50000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000500005000050000",
  "txid": "channeltxid01050000500005000050000500005000050000500005000050000",
  "channel_ids": [
    {
      "id": "nodeid030303030303030303030303030303030303030303030303030303030303",
      "channel_id": "channelid1100011000110001100011000110001100011000110001100011000",
      "channel_type": {
        "bits": [
          12,
          22
        ],
        "names": [
          "static_remotekey/even",
          "anchors/even"
        ]
      },
      "outnum": 1
    },
    {
      "id": "nodeid040404040404040404040404040404040404040404040404040404040404",
      "channel_id": "channelid1200012000120001200012000120001200012000120001200012000",
      "channel_type": {
        "bits": [
          12,
          22
        ],
        "names": [
          "static_remotekey/even",
          "anchors/even"
        ]
      },
      "outnum": 1
    },
    {
      "id": "nodeid050505050505050505050505050505050505050505050505050505050505",
      "channel_id": "channelid1300013000130001300013000130001300013000130001300013000",
      "channel_type": {
        "bits": [
          12,
          22
        ],
        "names": [
          "static_remotekey/even",
          "anchors/even"
        ]
      },
      "outnum": 1
    }
  ],
  "failed": []
}

Example 2: