Questions tagged [child-pays-for-parent]

Child Pays For Parent (CPFP) is a technique for increasing the effective feerate of an unconfirmed transaction by spending one of its outputs in a high feerate transaction, encouraging miners to include both transactions in a block.

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Are there any pools or large miners running "child pays for parent" patch?

A feature available through pull #1647 gives the recipient of a transaction a method to help get a transaction to confirm. This feature is called "child pays for parent", and what it means is that ...
Stephen Gornick's user avatar
13 votes
1 answer
8k views

Replace-by-Fee vs Child-pays-for-Parent?

Both RBF and CPFP attempt to solve the problem of transactions not confirming because of an insufficient fee. What are the pros/cons of using one vs the other? Are both currently functional and ...
morsecoder's user avatar
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Can someone outline the full pros/cons of the various Replace-By-Fee proposals?

I've done some research myself, but I find that I'm either biased myself, or my sources themselves are biased. Does anyone have an objective analysis of the various proposals and their advantages/...
Josh Cincinnati's user avatar
10 votes
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7k views

Do unconfirmed transactions expire after some time?

Sometimes confirmation process is very slow. I think that is because of the price of the fee. In that time, is it possible to cancel the unconfirmed transaction and re-send with higher transaction fee?...
zono's user avatar
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8 votes
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Spending output of a low-fee transaction by following with higher-fee transaction

Suppose I broadcast a transaction A with very low (or zero) fee. Normally, it would take a long time to confirm. Suppose, then I broadcast another transaction B that spends a (yet unconfirmed) output ...
Vladimir Reshetnikov's user avatar
6 votes
1 answer
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A question about CPFP relaying policy

Let's say I broadcast a transaction tx0 signaling RBF replaceability. Later on, send another transaction tx1 that spends the same inputs of tx0, but this time with higher fees. In this case, tx0 is ...
Burak's user avatar
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Bitcoin.conf setting for CPFP - how can I enable longer 'chains' of unconfirmed transactions?

I often receive an -32700 'Insufficient Funds' error when attempting to create 'child pays for parent' (CPFP) transactions using unconfirmed change output. This can be problematic since it can prevent ...
qmux's user avatar
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5 votes
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How does first seen replace by fee work?

This pull request describes first-seen replace-by-fee. How is it different from normal replace-by-fee, and how does it compare to child-pays-for-parent?
Nick ODell's user avatar
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Why do Anchor Outputs need to enforce an nSequence of 1?

Quote from https://bitcoinops.org/en/topics/anchor-outputs: As of this writing, the most recent versions of the design add two outputs to the commitment transaction—one for each LN party—and require ...
Dalit Sairio's user avatar
5 votes
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what is meant by DEFAULT_ANCESTOR_LIMIT in child pay for parent?

Why is 25 the max parents a child can rescue in a child pay for parent? I don't think I understand what DEFAULT_ANCESTOR_LIMIT = 25 means. Does that also mean that the child transaction has 25 ...
anu's user avatar
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Does miner with CPFP look through all the possible combinations of descendants to find the one with the highest fee?

When there is a transaction with more descendants, does CPFP policy look through all possible combination of descendants to consider "together", to find which one has the best fee? For example, when ...
Karel Bílek's user avatar
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spending unconfirmed utxos which exist in the tail of mempool queue

I have some unconfirmed utxos with: sat_per_vbyte=1, which probably exist in the tail of the mempool queue, e.g. 22300/22385. They are being kept in: "unconfirmed" since 3 months ago. And ...
Jack Zhu's user avatar
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4 votes
1 answer
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How does one create another transaction when all funds are tied up in an unconfirmed previous transaction?

If I have only one UTXO and I spend from it that's fine, I send myself back the change and that works how I expect it to. However if I want to create a new transaction in the time that the first ...
Kevin Kelbie's user avatar
4 votes
1 answer
2k views

How to issue a CPFP?

I was reading about CPFP (child pays for parents) recently and I didn't completely get the concept of it. Can someone please give me a brief explanation of how it should be done and what are the ...
user6613235's user avatar
4 votes
1 answer
341 views

Lightning bumpfee completes but doesnt create a new transaction. Instead it waits in "pending sweeps"

I had a Lightning channel open transaction pending for 24 hours due to a low fee. So I issued a bumpfee for the output index like so: lncli wallet bumpfee --sat_per_byte <new_fee> <txid>:&...
7hacker's user avatar
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Best Practices with Multiple CPFPs & CPFP + RBF

Problem: In times of escalating fees and a growing mempool, multiple prioritizations may be necessary if the initial Child Pays For Parent (CPFP) transaction fails to offer a sufficient fee. However, ...
Michael Tidwell's user avatar
3 votes
1 answer
176 views

Comparison between CPFP and BIP125 for fee bumping

As far as I understood so far, CPFP and BIP125 are both designed to help spenders to make new transactions using an input of an unconfirmed transaction by paying the cost. The most well known use case ...
Amir reza Riahi's user avatar
3 votes
1 answer
193 views

Transaction with a high fee keeps getting skipped... Reason why?

I was sent a transaction that has been unconfirmed for 3 days now - but the feerate is relatively high (53.8 sat/vB). Blocks have been confirming transactions with lower feerates for days, but for ...
user115073's user avatar
3 votes
1 answer
294 views

Why won't a transaction with 888/byte confirm after 11+ hours?

I have this transaction that I can't figure out why it won't confirm. https://blockchain.info/tx/92b33d498a35d47f03eee14f258cf9b3f015a5d12856eb05e47534e664344239 If I check https://bitcoinfees.earn....
Rob's user avatar
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Is it possible to get CPFP information from full node, without requesting full mempool dump?

I want to get CPFP information out of a full node—that is, ancestorsize and ancestorfees—in order to calculate the necessary fee for either CPFP, or RBF if possible. Can I get this information through ...
Karel Bílek's user avatar
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3 votes
2 answers
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LND funding transaction stuck in mempool due to low fees

I have a funding transaction stuck in mempool due to low fees. Searchng around I have find that there is "BumpFee" wallet option to push your transaction. i have tried in this way: ~$ lncli wallet ...
Butta's user avatar
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3 votes
1 answer
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Unilateral closing transaction for channel stuck in mempool

I've now had an unilateral closing of a channel stuck in the mempool for over two months. I want to transfer the unconfirmed sum to another wallet, so I want to create a new transaction which also is ...
Gimberg's user avatar
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2 votes
2 answers
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How does Bitcoin core knows whether CPFP carve out rule is already used?

Bitcoin node has 2 rules that limit the use of CPFP: number of descendants (including transaction itself) can't be more than 25 total size of transaction and all its descendants can't be more than ...
LeaBit's user avatar
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2 votes
1 answer
130 views

What are all the rules related to CPFP fee bumping?

Here Murch defined the rules related to RBF, as one of the techniques for fee bumping. He also posted a link to Bitcoin Core's official documentation related to the implementation of RBF (link). ...
LeaBit's user avatar
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2 answers
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What types of RBF exist and which one does Bitcoin Core support and use by default?

As far as I know Bitcoin Core knows two types of RBF. These are Full RBF and Opt-in Full RBF. In both cases, the transaction will be replaced if a new one arrives that consumes at least one of the ...
LeaBit's user avatar
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2 votes
1 answer
86 views

Do miners have an incentive to confirm various transactions from same address?

Mempool is really clogged those days. I tried to make a transaction from one of my address to a friend. As we didn't care about confirmation time, I put a 5 sats/bit fee. 2 weeks later, transaction ...
Turbolay's user avatar
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2 votes
2 answers
264 views

Does parent also pay for child?

One Bitcoin core mining policy is CPFP - child pays for parent. That is, transaction with high fee pays for its parent. Does it also work the other way - that is, does transaction with high fee pays ...
Karel Bílek's user avatar
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2 votes
1 answer
168 views

What happens if the commitment tx fee is too low?

How often are commitment tx fees negotiated? Is it every time a payment is made and a new commitment transaction is formed? What about if there are no payments but both nodes see that the on chain ...
Darius's user avatar
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Does bitcoin core node relay those child-pay-for-parent transactions?

I am trying to understand how the relay mechanism works in bitcoin? I understand how CPFP transaction works, but how those transactions get relayed to miner nodes in the first place? the reason is ...
devildeer's user avatar
2 votes
2 answers
267 views

Why are negative fees not allowed?

Why does Bitcoin consensus require blocks to contain only non negative fee transactions? Also why does the coinbase have to be the first transaction in a block with this rule lifted? Instead of ...
Leonidaz0r's user avatar
2 votes
2 answers
333 views

Is it okay to chain multiple unconfirmed transactions?

Is it okay to chain and broadcast multiple unconfirmed transactions? For example: I have two confirmed UTXOs UC1 and UC2. Using both as inputs, I then create and broadcast transaction T1, which ...
abianchessi's user avatar
2 votes
1 answer
342 views

Bump zero fee transaction with CPFP

I want to first create a transaction with 0 fee (tx1). Next, I am going to use an output of tx1 as an input in another transaction with the necessary fees. The issue is now that tx1 gets rejected by ...
f4r4's user avatar
  • 181
2 votes
1 answer
80 views

Can I save mining fees when doing transitive transactions?

If I create two transactions: Send BTC from output X to Y, no fee is attached. Send BTC from output Y to Z, fee is attached (this depends on the previous tx). Would nodes propegate these two ...
ripper234's user avatar
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1 vote
1 answer
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CPFP: Child Pays For Parent Clarification Needed

With the Child Pays for Parent (CPFP) Do I sent more bitcoin to the SAME address the stuck transaction was sent to? The second transaction (with fees high enough to cover both transactions) will push ...
Shes2smart's user avatar
1 vote
1 answer
1k views

How to do RBF using the Ledger Nano / Ledger Live

Would anyone here please be able to tell me how to do RBF using the ledger nano- I can see the transaction has been stuck for about 12 hours now. The TX is ...
Joaquin Birba's user avatar
1 vote
3 answers
793 views

Where do I find my Blockchain wallet's change address?

Six days ago, I sent some bitcoin and it hasn't been confirmed. In an attempt to execute a Child-pays-for-parent transaction, I used my mnemonic seed to derive addresses from my blockchain wallet(in ...
Livid's user avatar
  • 11
1 vote
0 answers
42 views

Building a CPFP raw transaction to confirm a force-closed Lightning channel [closed]

I am attempting to use bitcoin-cli createrawtransaction to build a CPFP transaction to pay for a low-fee channel close that has been unconfirmed for over a week. I have all of the details, i.e, txid, ...
The Daniel's user avatar
1 vote
1 answer
110 views

Is there a formula to know how much to bump your change input to get a desired sat/vbyte for P2TR transactions?

so i know x = (sat/vB_effective * (vB_parent + vB_child) - current_parent_fee) / vB_child where x is the child fee (in sats/vbyte) that would need to get bumped. so this is figured off the child fee. ...
Joe T's user avatar
  • 13
1 vote
1 answer
86 views

Bitcoin transaction stuck

I sent a bitcoin transaction and after sending it I realized that the fee was too low. https://www.blockchain.com/btc/tx/a398c4a2db165bd35435e381a6d185a14aa7a3df40aeca157dd89e4efd2e20d1 in an ...
Mateus Gutemberg's user avatar
1 vote
1 answer
77 views

Child Pays for Parent transactions get stuck on testnet

I'm building a service prototype by reusing Electrum code and generated 4 consequent transactions which are CPFP type on the testnet. They are staying unconfirmed for several hours but test ...
Ilya Evdokimov's user avatar
0 votes
1 answer
1k views

From multibit to electrum : low fee and unconfirmed parent

I made 3 btc transfer from my old Multibit classic wallet a few weeks ago (dec. 11), then I discovered that the fee was far too low for the transfers to be confirmed. I then restored my original ...
soleshoe's user avatar
  • 101
0 votes
1 answer
346 views

Why is CPFP (Child pay for parent) immune to double spend?

Assuming I have 10 Bitcoins in my wallet and I send 4 BTC with a tiny fee and it gets stuck in the mempool due to a low transaction fee. If I understand CPFP correctly I would then send a second ...
Cedric Martens's user avatar
0 votes
1 answer
6k views

Electrum Wallet How to use "Child Pays for Parent"

my transaction is here: https://blockchain.info/tr/tx/cb371b331e99eccb2d7447f4fe02417812ad066de21843fa156d4890e2cdf329 The reciever is a exchange wallet I don't know the reciever's private key. it got ...
Micheal J.'s user avatar
0 votes
0 answers
49 views

Tx Pending. CPFP, BumpFee or do nothing?

I have a stuck/pending tx - 14 hours. Its marked as RBF. I'm a bit below the median tx fee. (currently 67 sat/vB vs ~96 sat/vB). BitcoinFees seems to indicate I should get confirmed within 24 hours. I'...
Simon Woods's user avatar
0 votes
0 answers
243 views

My bitcoin core transaction is stuck in the mempool. I am the sender. I need help with either accelerating this transaction or preparing a CPFP trx

Hello and thank you for looking at my first question. This is my first question ever on StackExchange. I engaged in Bitcoin transactions as the sender; trying to send some Bitcoin to my CashApp so I ...
vittorrio's user avatar
0 votes
1 answer
204 views

In Blue Wallet 6.0.2 for iOS, pressing on Bump Fee causes an infinite wait. Any idea why?

Think there might be a bug in Blue Wallet, I imported the said wallet to BlockChain.com iOS App, but the unconfirmed transaction was not even shown there. In short, how can I CPFP my transaction now?
Nir O.'s user avatar
  • 101