When my consumer invokes my app, he passes as an enter parameter the specified worth of the TX charge in satoshis per byte. I create a PSBT by calling createpsbt(). I exert full management over the dedication of inputs and outputs. For instance, I do not name walletcreatefundedpsbt(), as a result of I do not need bitcoind to pick out inputs on my behalf. I’ve a rooster and egg drawback in that I must name createpsbt() with a purpose to decide the dimensions of the TX in bytes, however I must specify the charge quantity earlier than the decision to createpsbt(). The most effective resolution that I can consider is to execute a dummy name to createpsbt() utilizing a dummy charge worth, then measure the dimensions of the TX, then do an actual name to createpsbt() after accurately calculating the charge quantity. Is there a greater approach?
Edit: I wish to spend all UTXOs. I would like two outputs, one to obtain a set quantity, the opposite to obtain change much less the charge. I’ve tried many incantations, I can not get it to work. This is my newest try:
raw_psbt = rpc.walletcreatefundedpsbt(
# all UTXOs, as returned by listunspent():
inputs,
# one recipient: [ { addr : amount } ]
outputs,
0, # locktime
{
"replaceable" : True,
# I would really like for the change much less the charge to go right here:
"changeAddress" : xxx,
"includeWatching" : True,
"feeRate" : 0.005,
}
)
This fails with Signing transaction failed (-4). Any thought what I am doing incorrect?
Edit #2: I can not use walletcreatefundedpsbt() as recommended beneath to create the PSBT, as a result of that operate requires that its inputs be “solvable”, which isn’t the case in my surroundings. Extra information at this hyperlink:
Errors with walletcreatefundedpsbt & non-solvable UTXOs
So my unique query stays unresolved at this level.
Edit #3: So I requested on Slack. The issue is that our UTXOs are 1) not “solvable” and a pair of) can’t be expressed within the descriptor language, so Bitcoin Core has no strategy to calculate the TX measurement earlier than the TX is signed. Apparently I must calculated it manually as defined within the hooked up screenshot.
