lightning-txprepare – Command to prepare to withdraw funds from the internal wallet

SYNOPSIS

txprepare outputs [feerate] [minconf] [utxos]

DESCRIPTION

The txprepare RPC command creates an unsigned transaction which spends funds from c-lightning’s internal wallet to the outputs specified in outputs.

The outputs is the array of output that include destination and amount({destination: amount}). Its format is like: [{address1: amount1}, {address2: amount2}] or [{address: all}]. It supports the any number of outputs.

The destination of output is the address which can be of any Bitcoin accepted type, including bech32.

The amount of output is the amount to be sent from the internal wallet (expressed, as name suggests, in amount). The string all can be used to specify all available funds. Otherwise, it is in amount 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.

feerate is an optional feerate to use. It can be one of the strings urgent (aim for next block), normal (next 4 blocks or so) or slow (next 100 blocks or so) to use lightningd’s internal estimates: normal is the default.

Otherwise, feerate is a number, with an optional suffix: perkw means the number is interpreted as satoshi-per-kilosipa (weight), and perkb means it is interpreted bitcoind-style as satoshi-per-kilobyte. Omitting the suffix is equivalent to perkb.

minconf specifies the minimum number of confirmations that used outputs should have. Default is 1.

utxos specifies the utxos to be used to fund the transaction, as an array of “txid:vout”. These must be drawn from the node’s available UTXO set.

txprepare is similar to the first part of a withdraw command, but supports multiple outputs and uses outputs as parameter. The second part is provided by txsend.

RETURN VALUE

On success, an object with attributes unsigned_tx and txid will be returned. You need to hand txid to txsend or txdiscard, as the inputs of this transaction are reserved until then, or until the daemon restarts.

unsigned_tx represents the raw bitcoin transaction (not yet signed) and txid represent the bitcoin transaction id.

On failure, an error is reported and the transaction is not created.

The following error codes may occur:

  • -1: Catchall nonspecific error.
  • 301: There are not enough funds in the internal wallet (including fees) to create the transaction.
  • 302: The dust limit is not met.

AUTHOR

Rusty Russell <rusty@rustcorp.com.au> is mainly responsible.

SEE ALSO

lightning-withdraw(7), lightning-txsend(7), lightning-txdiscard(7)