0 sat/byte fee ?

[balambala]

I am trying to force my node to accept and broadcast 0 fee transactions or 0.1 sat/byte transactions.

I set on the config file the following settings but it triggers the node to not start (not accept mintxfee argument as valid) :

minrelaytxfee=0
mintxfee=0



I am using the most recent bitcoind client version.

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[BitMaxz]

Are you going to pay zero fees?

Read this "Free transaction relay policy".

Historic rules for free transactions
A transaction was safe to send without fees if these conditions were met:

It is smaller than 1,000 bytes.
All outputs are 0.01 BTC or larger.
Its priority is large enough (see above)

And I think you can fix this issue by using this settings below:

mintxfee=0.00000001
minrelaytxfee=0.00000001

Got that source from here https://github.com/bitcoin/bitcoin/issues/5746

[bitmover]

Are you going to pay zero fees?

Read this "Free transaction relay policy".

Historic rules for free transactions
A transaction was safe to send without fees if these conditions were met:

It is smaller than 1,000 bytes.
All outputs are 0.01 BTC or larger.
Its priority is large enough (see above)

 1 sat byte is the minimum fee possible for now.

As far as I know, since 2016, no free transactions are allowed anymore. Even in your quoted text it says "was safe to send" . And those as historic rules, rules which doesn't apply anymore

[mocacinno]

Here you go... This should work (as long as you have a linux box with all dependencies installed).

It's

Code:

cd ~
git clone https://github.com/bitcoin/bitcoin/
cd ~/bitcoin/src/wallet/
sed -i 's/static const CAmount DEFAULT_TRANSACTION_MINFEE = 1000;/static const CAmount DEFAULT_TRANSACTION_MINFEE = 0;/g' wallet.h
sed -i 's/static const CAmount WALLET_INCREMENTAL_RELAY_FEE = 5000;/static const CAmount WALLET_INCREMENTAL_RELAY_FEE = 0;/g' wallet.h
cd ~/bitcoin
./autogen.sh
./configure
make
cd ~/bitcoin/src
./bitcoind -daemon -mintxfee=0

But even if you edit the sourcecode and run the modified version, you probably won't receive any 0 fee transactions, since all other nodes you are connected to will reject said transactions, hence they won't broadcast them to you...
This will only work if you're connected to other old or patched nodes that accept and relay 0 fee transactions, or if you use your node to broadcast your own 0 fee transaction... In the latter case any other node you relay the 0 fee transaction to will probably reject it anyways, and no miner will probably touch the 0 fee transaction.

It's not because it's technically possible that it's a wise idear to do this

[josephdd1]

If this was real or possible then the whole Bitcoin mining industry would collapse.
Why would you want to do this anyway and change the status quo?

[Rath_]

If this was real or possible then the whole Bitcoin mining industry would collapse.
Why would you want to do this anyway and change the status quo?

It wouldn't collapse. Miners are still the ones who choose which transactions get to be included in the block they mine. First Bitcoin transactions were basically free of charge because of no block limit and empty blocks.

[bitmover]

If this was real or possible then the whole Bitcoin mining industry would collapse.
Why would you want to do this anyway and change the status quo?

It wouldn't collapse. Miners are still the ones who choose which transactions get to be included in the block they mine. First Bitcoin transactions were basically free of charge because of no block limit and empty blocks.

Additionally, miners are not rewarded just by transaction fees. There is sti the incentive of 12.5 BTC per block.
Also, if even so 12.5 is not profitable, professional miners can just leave until the hashrate drops and mining becomes profitable  again.

So dont worry about miners, they are fine.

[nc50lc]

First, make sure not to add a "#" in front of the line 'cause it will be considered as a comment.
And use one line per config.

The value uses BTC/kB unit so: 0.00001BTC/kB is the default which is 1sat/B.
Try to use these values (0.1 sat/B you said?) instead of 0:

Code:

minrelaytxfee=0.000001
mintxfee=0.000001

Or did you mean 0.1sat/kB? I haven't tried it because it's way too low and probably wouldn't work but, try to use these values:

Code:

minrelaytxfee=1e-9
mintxfee=1e-9

1e-8 for 1 sat/kB | 0.001 sat/B | 0.00000001 BTC/kB
1e-7 for 10 sat/kB | 0.01 sat/B | 0.0000001 BTC/kBY tho?

[slaman29]

Sorry to butt in but does this mean that it is not possible at all anymore to get 0 fee transactions confirmed?

Because as user above puts it, you can possibly sign and broadcast the transaction, but since nobody will confirm it, it's just not worth to do it anymore? Why do people still try?

[mocacinno]

Sorry to butt in but does this mean that it is not possible at all anymore to get 0 fee transactions confirmed?

Because as user above puts it, you can possibly sign and broadcast the transaction, but since nobody will confirm it, it's just not worth to do it anymore? Why do people still try?

Somewhere around 2016-2017, i witnessed people creating 0 fee transactions and getting them confirmed. As long as a single miner runs an old node, a patched node or an alternative node (like btcd) that is configured to accept and relay 0 fee transactions, AND still uses the old, deprecated priority mechanism you can always try to setup a patched node and connect directly to this mining node, then create a 0 fee transaction and get it broadcasted to this miner's node...
However, at this point in time, you'd need very specific and detailed info about which miners would be running such a patched and alternatively-configured node, my guess would be there aren't many of those miners left.

And in the odd chance you do get a 0 fee transaction in his/her node's mempool, and your transaction has very high priority (and the miner still reserves a space in his/her block for high priority transactions), the miner would still need to find a block header whose hash is under the current target (ie solve the block).

Odds are small, very, very, small... But i don't think they're absolute 0.

[2double0]

Sorry to butt in but does this mean that it is not possible at all anymore to get 0 fee transactions confirmed?

Because as user above puts it, you can possibly sign and broadcast the transaction, but since nobody will confirm it, it's just not worth to do it anymore? Why do people still try?

I am aware  that there are a few 'good' miners who still mine BTC as a hobby and not for their financial profits, if they decide to go for charity mining for some time where they go below ground level of 1 sat/byte and choose to take 0 sat/byte transactions in their block, there are 100% chances of getting your 0 sat 'fully free' transactions confirmed. But I thought about a question that comes in the way, how much time will it take from them to confirm those transactions? Because not every other miner there will do this, so those who are doing it need to have enough hash power to get a block in their hands.

[Zicadis]

Sorry to butt in but does this mean that it is not possible at all anymore to get 0 fee transactions confirmed?

Because as user above puts it, you can possibly sign and broadcast the transaction, but since nobody will confirm it, it's just not worth to do it anymore? Why do people still try?

I am aware  that there are a few 'good' miners who still mine BTC as a hobby and not for their financial profits, if they decide to go for charity mining for some time where they go below ground level of 1 sat/byte and choose to take 0 sat/byte transactions in their block, there are 100% chances of getting your 0 sat 'fully free' transactions confirmed. But I thought about a question that comes in the way, how much time will it take from them to confirm those transactions? Because not every other miner there will do this, so those who are doing it need to have enough hash power to get a block in their hands.

Why would anyone want to waste electricity and money as a hobby?
Does it make any sense?
Even under a circumstance where they are doing it to get hash power, remember, accepting 0 sat or free transactions does not mean other miners would accept it as well.
It would get rejected and all that effort into getting it accepted would be wasted.

[josephdd1]

If this was real or possible then the whole Bitcoin mining industry would collapse.
Why would you want to do this anyway and change the status quo?

It wouldn't collapse. Miners are still the ones who choose which transactions get to be included in the block they mine. First Bitcoin transactions were basically free of charge because of no block limit and empty blocks.

Probably because back then it was not resource intensive to run a miner. People could get hundreds of btc with their home computers or old laptops.
Doing this now would collapse the industry. Or at least the Bictoin blockchain.

[Carlton Banks]

Even under a circumstance where they are doing it to get hash power, remember, accepting 0 sat or free transactions does not mean other miners would accept it as well.
It would get rejected and all that effort into getting it accepted would be wasted.

zero fee/free transactions aren't against the consensus rules. if a miner mines a block including free transactions, other miners (and non-mining nodes) will consider it valid

[pooya87]

Probably because back then it was not resource intensive to run a miner. People could get hundreds of btc with their home computers or old laptops.
Doing this now would collapse the industry. Or at least the Bictoin blockchain.

so you think mining industry where miners are getting paid 12.5BTC (or $125000) per block is going to collapse if fees were zero and they weren't getting the 1 satoshi/byte minimal fee which translates into 0.012BTC (or $120) with 1.2 MB block!

not to mention when you say "then" you are talking about the time when miners were getting paid 25BTC or $12500 in other words 10 times less than now!

[slaman29]

Somewhere around 2016-2017, i witnessed people creating 0 fee transactions and getting them confirmed. As long as a single miner runs an old node, a patched node or an alternative node (like btcd) that is configured to accept and relay 0 fee transactions, AND still uses the old, deprecated priority mechanism you can always try to setup a patched node and connect directly to this mining node, then create a 0 fee transaction and get it broadcasted to this miner's node...
However, at this point in time, you'd need very specific and detailed info about which miners would be running such a patched and alternatively-configured node, my guess would be there aren't many of those miners left.

And in the odd chance you do get a 0 fee transaction in his/her node's mempool, and your transaction has very high priority (and the miner still reserves a space in his/her block for high priority transactions), the miner would still need to find a block header whose hash is under the current target (ie solve the block).

Odds are small, very, very, small... But i don't think they're absolute 0.

Thank you for the answer. I admit I didn't really quite understand everything needed for a person to get the tx confirmed, but I understand that there is still a possibility, and because of that possibility, it could be worth just sending a transaction that's 0 fee you don't need to confirm in 1 month, and see if someone will take it.

Do those miners set it up like that on purpose I wonder?

[mocacinno]

Thank you for the answer. I admit I didn't really quite understand everything needed for a person to get the tx confirmed, but I understand that there is still a possibility, and because of that possibility, it could be worth just sending a transaction that's 0 fee you don't need to confirm in 1 month, and see if someone will take it.

Do those miners set it up like that on purpose I wonder?

Well... I wouldn't count on it... If you just create a 0 fee transaction, it'll allmost certainly get rejected by the nodes you are connected to if you try to broadcast it trough them, or relay it to them.
If you find a single node that still accepts a 0 fee transaction, odds are it'll just stay in the mempool of that single node untill it gets pruned after a couple of days since the odds are big this 0-fee-accepting node is only connected to nodes that reject 0 fee transactions...

What i meanth is that if you want to create a 0 fee transaction and even have a very small chance of getting it confirmed, you'll have to find a "path" of 0-fee-accepting node(s) that lead to a 0-fee-accepting node that belongs to a miner... Only if you find such a path, you'll have a (very small) chance the miner will put your transaction into the block he/she is working on, and an even small chance the miner finds a valid blockheader...
Finding 0-fee-accepting nodes is not easy to begin with... You can probably try to connect to as many nodes as possible and look at their versions, recent bitcoin core versions would have had to actively patch their node's code in order to accept 0 fee transactions (thus, the odds of them actually accepting said transactions is VERY small). Older core versions and alternative versions would (theoretically) have the highest odds of accepting 0 fee transactions.

If you want to test out wether or not a node accepts your transaction, you'll probably have to create 2 nodes on 2 different machines, connect them both to the node you are testing. Then broadcast your 0 fee transaction to said node from your first node and see if the tested node broadcast the 0 fee transaction to your second node. If it does, at least you know the tested node RELAYS 0 fee transactions
Here's a small, non-technical, intersting reading piece about how transaction relaying works... It's interesting, but it does not offer a real "answer" in this discussion tough => https://en.bitcoin.it/wiki/Network#Standard_relaying

[buwaytress]

In addition to the fine points already, would just like to add that it is not only still possible, but that there are still daily 0-fee transactions being transmitted and confirmed on the network. Only a handful, and a number that's fewer by the day, only 2 in the last 24 hours actually. These likely are just miners' own transactions, or txs of friends or whatever, merely including them in the blocks they find.

Thanks to mocha too for that useful bit on relay. Never did find any nodes accepting when last looking manually. All the broadcast services online also are pushing to upgraded nodes who'll reject 0-fees. Been a while since I'd seen anyone sharing one of them old setups.

[Red-Apple]

In addition to the fine points already, would just like to add that it is not only still possible, but that there are still daily 0-fee transactions being transmitted and confirmed on the network. Only a handful, and a number that's fewer by the day, only 2 in the last 24 hours actually.

for reference if someone wanted to analyze these transactions further:
list of transactions with zero fee that happened this year using https://blockchair.com/. god i love this block explorer. it has so many cool features to play around and analyze transactions and blocks,... the best thing is you can share the link of your customized sort.

note that i set iscoinbase to false to exclude them since coinbase are transactions also shown to have zero fee on the explorer.

These likely are just miners' own transactions, or txs of friends or whatever, merely including them in the blocks they find.

i checked a bunch of those transactions (obviously not all) and they were all payments made from a mining pool to its miners (spending coinbase transactions)

[Carlton Banks]

Thank you for the answer. I admit I didn't really quite understand everything needed for a person to get the tx confirmed, but I understand that there is still a possibility, and because of that possibility, it could be
What i meanth is that if you want to create a 0 fee transaction and even have a very small chance of getting it confirmed, you'll have to find a "path" of 0-fee-accepting node(s) that lead to a 0-fee-accepting node that belongs to a miner... Only if you find such a path, you'll have a (very small) chance the miner will put your transaction into the block he/she is working on, and an even small chance the miner finds a valid blockheader...
Finding 0-fee-accepting nodes is not easy to begin with... You can probably try to connect to as many nodes as possible and look at their versions, recent bitcoin core versions would have had to actively patch their node's code in order to accept 0 fee transactions (thus, the odds of them actually accepting said transactions is VERY small). Older core versions and alternative versions would (theoretically) have the highest odds of accepting 0 fee transactions.

If you want to test out wether or not a node accepts your transaction, you'll probably have to create 2 nodes on 2 different machines, connect them both to the node you are testing. Then broadcast your 0 fee transaction to said node from your first node and see if the tested node broadcast the 0 fee transaction to your second node. If it does, at least you know the tested node RELAYS 0 fee transactions
Here's a small, non-technical, intersting reading piece about how transaction relaying works... It's interesting, but it does not offer a real "answer" in this discussion tough => https://en.bitcoin.it/wiki/Network#Standard_relaying

or alternatively, just connect to miner nodes directly, and see which accept 0-fee transactions when you try to relay.

the block explorer sites usually publish the IP address of smaller miners. connect your Bitcoin node to those, and start trying.